Наследование ISaleStorage

This reverts commit 9045e90326.

SquirrelContract/SquirrelBusinessLogic/Implementations/ClientBusinessLogicContract.cs

@@ -0,0 +1,70 @@
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.StoragesContracts;
+using Microsoft.Extensions.Logging;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using SquirrelContract.DataModels;
+
+namespace SquirrelBusinessLogic.Implementations;
+
+internal class ClientBusinessLogicContract(IClientStorageContract clientStorageContract, ILogger logger) : IClientBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IClientStorageContract _clientStorageContract = clientStorageContract;
+
+    public List<ClientDataModel> GetAllClients()
+    {
+        _logger.LogInformation("GetAllClients");
+        return _clientStorageContract.GetList() ?? throw new NullListException();
+    }
+
+    public ClientDataModel GetClientByData(string data)
+    {
+        _logger.LogInformation("Get element by data: {data}", data);
+        if (data.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(data));
+        }
+        if (data.IsGuid())
+        {
+            return _clientStorageContract.GetElementById(data) ?? throw new ElementNotFoundException(data);
+        }
+        if (Regex.IsMatch(data, @"^((8|\+7)[\- ]?)?(\(?\d{3}\)?[\- ]?)?[\d\- ]{7,10}$"))
+        {
+            return _clientStorageContract.GetElementByPhoneNumber(data) ?? throw new ElementNotFoundException(data);
+        }
+        return _clientStorageContract.GetElementByFIO(data) ?? throw new ElementNotFoundException(data);
+    }
+
+    public void InsertClient(ClientDataModel clientDataModel)
+    {
+        _logger.LogInformation("New data: {json}", JsonSerializer.Serialize(clientDataModel));
+        ArgumentNullException.ThrowIfNull(clientDataModel);
+        clientDataModel.Validate();
+        _clientStorageContract.AddElement(clientDataModel);
+    }
+
+    public void UpdateClient(ClientDataModel clientDataModel)
+    {
+        _logger.LogInformation("Update data: {json}", JsonSerializer.Serialize(clientDataModel));
+        ArgumentNullException.ThrowIfNull(clientDataModel);
+        clientDataModel.Validate();
+        _clientStorageContract.UpdElement(clientDataModel);
+    }
+
+    public void DeleteClient(string id)
+    {
+        _logger.LogInformation("Delete by id: {id}", id);
+        if (id.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(id));
+        }
+        if (!id.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        _clientStorageContract.DelElement(id);
+    }
+}

SquirrelContract/SquirrelBusinessLogic/Implementations/CocktailBusinessLogicContract.cs

@@ -0,0 +1,79 @@
+using Microsoft.Extensions.Logging;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.StoragesContracts;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+
+namespace SquirrelBusinessLogic.Implementations;
+
+internal class CocktailBusinessLogicContract(ICocktailStorageContract cocktailStorageContract, ILogger logger) : ICocktailBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly ICocktailStorageContract _cocktailStorageContract = cocktailStorageContract;
+    public List<CocktailDataModel> GetAllCocktails()
+    {
+        _logger.LogInformation("GetAllCocktails");
+        return _cocktailStorageContract.GetList() ?? throw new NullListException();
+    }
+
+    public List<CocktailHistoryDataModel> GetCocktailHistoryByCocktail(string cocktailId)
+    {
+        _logger.LogInformation("GetCocktailHistoryByCocktail for {cocktailId}", cocktailId);
+        if (cocktailId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(cocktailId));
+        }
+        if (!cocktailId.IsGuid())
+        {
+            throw new ValidationException("The value in the field cocktailId is not a unique identifier.");
+        }
+        return _cocktailStorageContract.GetHistoryByCocktailId(cocktailId) ?? throw new NullListException();
+    }
+
+    public CocktailDataModel GetCocktailByData(string data)
+    {
+        _logger.LogInformation("Get element by data: {data}", data);
+        if (data.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(data));
+        }
+        if (data.IsGuid())
+        {
+            return _cocktailStorageContract.GetElementById(data) ?? throw new ElementNotFoundException(data);
+        }
+        return _cocktailStorageContract.GetElementByName(data) ?? throw new ElementNotFoundException(data);
+    }
+
+    public void InsertCocktail(CocktailDataModel cocktailDataModel)
+    {
+        _logger.LogInformation("New data: {json}", JsonSerializer.Serialize(cocktailDataModel));
+        ArgumentNullException.ThrowIfNull(cocktailDataModel);
+        cocktailDataModel.Validate();
+        _cocktailStorageContract.AddElement(cocktailDataModel);
+    }
+
+    public void UpdateCocktail(CocktailDataModel cocktailDataModel)
+    {
+        _logger.LogInformation("Update data: {json}", JsonSerializer.Serialize(cocktailDataModel));
+        ArgumentNullException.ThrowIfNull(cocktailDataModel);
+        cocktailDataModel.Validate();
+        _cocktailStorageContract.UpdElement(cocktailDataModel);
+    }
+
+    public void DeleteCocktail(string id)
+    {
+        _logger.LogInformation("Delete by id: {id}", id);
+        if (id.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(id));
+        }
+        if (!id.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        _cocktailStorageContract.DelElement(id);
+    }
+}

SquirrelContract/SquirrelBusinessLogic/Implementations/EmployeeBusinessLogicContract.cs

@@ -0,0 +1,104 @@
+using Microsoft.Extensions.Logging;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.StoragesContracts;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+
+namespace SquirrelBusinessLogic.Implementations;
+
+internal class EmployeeBusinessLogicContract(IEmployeeStorageContract employeeStorageContract, ILogger logger) : IEmployeeBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IEmployeeStorageContract _employeeStorageContract = employeeStorageContract;
+
+    public List<EmployeeDataModel> GetAllEmployees(bool onlyActive = true)
+    {
+        _logger.LogInformation("GetAllEmployees params: {onlyActive}", onlyActive);
+        return _employeeStorageContract.GetList(onlyActive) ?? throw new NullListException();
+    }
+
+    public List<EmployeeDataModel> GetAllEmployeesByPost(string postId, bool onlyActive = true)
+    {
+        _logger.LogInformation("GetAllEmployees params: {postId}, {onlyActive},", postId, onlyActive);
+        if (postId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(postId));
+        }
+        if (!postId.IsGuid())
+        {
+            throw new ValidationException("The value in the field postId is not a unique identifier.");
+        }
+        return _employeeStorageContract.GetList(onlyActive, postId) ?? throw new NullListException();
+    }
+
+    public List<EmployeeDataModel> GetAllEmployeesByBirthDate(DateTime fromDate, DateTime toDate, bool onlyActive = true)
+    {
+        _logger.LogInformation("GetAllEmployees params: {onlyActive}, {fromDate}, {toDate}", onlyActive, fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        return _employeeStorageContract.GetList(onlyActive, fromBirthDate: fromDate, toBirthDate: toDate) ?? throw new NullListException();
+    }
+
+    public List<EmployeeDataModel> GetAllEmployeesByEmploymentDate(DateTime fromDate, DateTime toDate, bool onlyActive = true)
+    {
+        _logger.LogInformation("GetAllEmployees params: {onlyActive}, {fromDate}, {toDate}", onlyActive, fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        return _employeeStorageContract.GetList(onlyActive, fromEmploymentDate: fromDate, toEmploymentDate: toDate) ?? throw new NullListException();
+    }
+
+    public EmployeeDataModel GetEmployeeByData(string data)
+    {
+        _logger.LogInformation("Get element by data: {data}", data);
+        if (data.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(data));
+        }
+        if (data.IsGuid())
+        {
+            return _employeeStorageContract.GetElementById(data) ?? throw new ElementNotFoundException(data);
+        }
+        if (Regex.IsMatch(data, @"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"))
+        {
+            return _employeeStorageContract.GetElementByEmail(data) ?? throw new ElementNotFoundException(data);
+        }
+        return _employeeStorageContract.GetElementByFIO(data) ?? throw new ElementNotFoundException(data);
+    }
+
+    public void InsertEmployee(EmployeeDataModel employeeDataModel)
+    {
+        _logger.LogInformation("New data: {json}", JsonSerializer.Serialize(employeeDataModel));
+        ArgumentNullException.ThrowIfNull(employeeDataModel);
+        employeeDataModel.Validate();
+        _employeeStorageContract.AddElement(employeeDataModel);
+    }
+
+    public void UpdateEmployee(EmployeeDataModel employeeDataModel)
+    {
+        _logger.LogInformation("Update data: {json}", JsonSerializer.Serialize(employeeDataModel));
+        ArgumentNullException.ThrowIfNull(employeeDataModel);
+        employeeDataModel.Validate();
+        _employeeStorageContract.UpdElement(employeeDataModel);
+    }
+
+    public void DeleteEmployee(string id)
+    {
+        _logger.LogInformation("Delete by id: {id}", id);
+        if (id.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(id));
+        }
+        if (!id.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        _employeeStorageContract.DelElement(id);
+    }
+}

SquirrelContract/SquirrelBusinessLogic/Implementations/PostBusinessLogicContract.cs

@@ -0,0 +1,92 @@
+using Microsoft.Extensions.Logging;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.StoragesContracts;
+using System.Text.Json;
+
+namespace SquirrelBusinessLogic.Implementations;
+
+internal class PostBusinessLogicContract(IPostStorageContract postStorageContract, ILogger logger) : IPostBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IPostStorageContract _postStorageContract = postStorageContract;
+    public List<PostDataModel> GetAllPosts(bool onlyActive = true)
+    {
+        _logger.LogInformation("GetAllPosts params: {onlyActive}", onlyActive);
+        return _postStorageContract.GetList(onlyActive) ?? throw new NullListException();
+    }
+
+    public List<PostDataModel> GetAllDataOfPost(string postId)
+    {
+        _logger.LogInformation("GetAllDataOfPost for {postId}", postId);
+        if (postId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(postId));
+        }
+        if (!postId.IsGuid())
+        {
+            throw new ValidationException("The value in the field postId is not a unique identifier.");
+        }
+        return _postStorageContract.GetPostWithHistory(postId) ?? throw new NullListException();
+    }
+
+    public PostDataModel GetPostByData(string data)
+    {
+        _logger.LogInformation("Get element by data: {data}", data);
+        if (data.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(data));
+        }
+        if (data.IsGuid())
+        {
+            return _postStorageContract.GetElementById(data) ?? throw new ElementNotFoundException(data);
+        }
+        return _postStorageContract.GetElementByName(data) ?? throw new ElementNotFoundException(data);
+    }
+
+    public void InsertPost(PostDataModel postDataModel)
+    {
+        _logger.LogInformation("New data: {json}", JsonSerializer.Serialize(postDataModel));
+        ArgumentNullException.ThrowIfNull(postDataModel);
+        postDataModel.Validate();
+        _postStorageContract.AddElement(postDataModel);
+    }
+
+    public void UpdatePost(PostDataModel postDataModel)
+    {
+        _logger.LogInformation("Update data: {json}", JsonSerializer.Serialize(postDataModel));
+        ArgumentNullException.ThrowIfNull(postDataModel);
+        postDataModel.Validate();
+        _postStorageContract.UpdElement(postDataModel);
+    }
+
+    public void DeletePost(string id)
+    {
+        _logger.LogInformation("Delete by id: {id}", id);
+        if (id.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(id));
+        }
+        if (!id.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        _postStorageContract.DelElement(id);
+    }
+
+    public void RestorePost(string id)
+    {
+        _logger.LogInformation("Restore by id: {id}", id);
+        if (id.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(id));
+        }
+        if (!id.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        _postStorageContract.ResElement(id);
+    }
+}

SquirrelContract/SquirrelBusinessLogic/Implementations/SalaryBusinessLogicContract.cs

@@ -0,0 +1,63 @@
+using BarBelochkaContract.DataModels;
+using Microsoft.Extensions.Logging;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.StoragesContracts;
+
+namespace SquirrelBusinessLogic.Implementations;
+
+internal class SalaryBusinessLogicContract(ISalaryStorageContract salaryStorageContract,
+    ISaleStorageContract saleStorageContract, IPostStorageContract postStorageContract, IEmployeeStorageContract employeeStorageContract, ILogger logger) : ISalaryBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly ISalaryStorageContract _salaryStorageContract = salaryStorageContract;
+    private readonly ISaleStorageContract _saleStorageContract = saleStorageContract;
+    private readonly IPostStorageContract _postStorageContract = postStorageContract;
+    private readonly IEmployeeStorageContract _employeeStorageContract = employeeStorageContract;
+    public List<SalaryDataModel> GetAllSalariesByPeriod(DateTime fromDate, DateTime toDate)
+    {
+        _logger.LogInformation("GetAllSalaries params: {fromDate}, {toDate}", fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        return _salaryStorageContract.GetList(fromDate, toDate) ?? throw new NullListException();
+    }
+
+    public List<SalaryDataModel> GetAllSalariesByPeriodByEmployee(DateTime fromDate, DateTime toDate, string employeeId)
+    {
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        if (employeeId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(employeeId));
+        }
+        if (!employeeId.IsGuid())
+        {
+            throw new ValidationException("The value in the field employeeId is not a unique identifier.");
+        }
+        _logger.LogInformation("GetAllSalaries params: {fromDate}, {toDate}, {employeeId}", fromDate, toDate, employeeId);
+        return _salaryStorageContract.GetList(fromDate, toDate, employeeId) ?? throw new NullListException();
+    }
+
+    public void CalculateSalaryByMounth(DateTime date)
+    {
+        _logger.LogInformation("CalculateSalaryByMounth: {date}", date);
+        var startDate = new DateTime(date.Year, date.Month, 1);
+        var finishDate = new DateTime(date.Year, date.Month, DateTime.DaysInMonth(date.Year, date.Month));
+        var employees = _employeeStorageContract.GetList() ?? throw new NullListException();
+        foreach (var employee in employees)
+        {
+            var sales = _saleStorageContract.GetList(startDate, finishDate, employeeId: employee.Id)?.Sum(x => x.Sum) ??
+                throw new NullListException();
+            var post = _postStorageContract.GetElementById(employee.PostId) ??
+                throw new NullListException();
+            var salary = post.Salary + sales * 0.1;
+            _logger.LogDebug("The employee {employeeId} was paid a salary of {salary}", employee.Id, salary);
+            _salaryStorageContract.AddElement(new SalaryDataModel(employee.Id, finishDate, salary));
+        }
+    }
+}

SquirrelContract/SquirrelBusinessLogic/Implementations/SaleBusinessLogicContract.cs

@@ -0,0 +1,116 @@
+using Microsoft.Extensions.Logging;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.StoragesContracts;
+using System.Text.Json;
+
+namespace SquirrelBusinessLogic.Implementations;
+
+internal class SaleBusinessLogicContract(ISaleStorageContract
+saleStorageContract, ILogger logger) : ISaleBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly ISaleStorageContract _saleStorageContract = saleStorageContract;
+
+    public List<SaleDataModel> GetAllSalesByPeriod(DateTime fromDate, DateTime toDate)
+    {
+        _logger.LogInformation("GetAllSales params: {fromDate}, {toDate}", fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        return _saleStorageContract.GetList(fromDate, toDate) ?? throw new NullListException();
+    }
+
+    public List<SaleDataModel> GetAllSalesByEmployeeByPeriod(string employeeId, DateTime fromDate, DateTime toDate)
+    {
+        _logger.LogInformation("GetAllSales params: {employeeId}, {fromDate}, {toDate}", employeeId, fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        if (employeeId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(employeeId));
+        }
+        if (!employeeId.IsGuid())
+        {
+            throw new ValidationException("The value in the field employeeId is not a unique identifier.");
+        }
+        return _saleStorageContract.GetList(fromDate, toDate, employeeId: employeeId) ?? throw new NullListException();
+    }
+
+    public List<SaleDataModel> GetAllSalesByClientByPeriod(string clientId, DateTime fromDate, DateTime toDate)
+    {
+        _logger.LogInformation("GetAllSales params: {buyerId}, {fromDate}, {toDate}", clientId, fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        if (clientId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(clientId));
+        }
+        if (!clientId.IsGuid())
+        {
+            throw new ValidationException("The value in the field clientId is not a unique identifier.");
+        }
+        return _saleStorageContract.GetList(fromDate, toDate, clientId: clientId) ?? throw new NullListException();
+    }
+
+    public List<SaleDataModel> GetAllSalesByCocktailByPeriod(string cocktailId, DateTime fromDate, DateTime toDate)
+    {
+        _logger.LogInformation("GetAllSales params: {cocktailId}, {fromDate}, {toDate}", cocktailId, fromDate, toDate);
+        if (fromDate.IsDateNotOlder(toDate))
+        {
+            throw new IncorrectDatesException(fromDate, toDate);
+        }
+        if (cocktailId.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(cocktailId));
+        }
+        if (!cocktailId.IsGuid())
+        {
+            throw new ValidationException("The value in the field cocktailId is not a unique identifier.");
+        }
+        return _saleStorageContract.GetList(fromDate, toDate, cocktailId: cocktailId) ?? throw new NullListException();
+    }
+
+    public SaleDataModel GetSaleByData(string data)
+    {
+        _logger.LogInformation("Get element by data: {data}", data);
+        if (data.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(data));
+        }
+        if (!data.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        return _saleStorageContract.GetElementById(data) ?? throw new ElementNotFoundException(data);
+    }
+
+    public void InsertSale(SaleDataModel saleDataModel)
+    {
+        _logger.LogInformation("New data: {json}", JsonSerializer.Serialize(saleDataModel));
+        ArgumentNullException.ThrowIfNull(saleDataModel);
+        saleDataModel.Validate();
+        _saleStorageContract.AddElement(saleDataModel);
+    }
+
+    public void CancelSale(string id)
+    {
+        _logger.LogInformation("Cancel by id: {id}", id);
+        if (id.IsEmpty())
+        {
+            throw new ArgumentNullException(nameof(id));
+        }
+        if (!id.IsGuid())
+        {
+            throw new ValidationException("Id is not a unique identifier");
+        }
+        _saleStorageContract.DelElement(id);
+    }
+}

SquirrelContract/SquirrelBusinessLogic/SquirrelBusinessLogic.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+	<ItemGroup>
+		<InternalsVisibleTo Include="SquirrelTests" />
+		<InternalsVisibleTo Include="DynamicProxyGenAssembly2" />
+	</ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\SquirrelContract\SquirrelContract.csproj" />
+  </ItemGroup>
+
+</Project>

SquirrelContract/SquirrelContract.sln

@@ -1,10 +1,16 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
-VisualStudioVersion = 17.12.35707.178 d17.12
+VisualStudioVersion = 17.12.35707.178
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SquirrelContract", "SquirrelContract\SquirrelContract.csproj", "{3B0E65D7-E64B-4893-803B-A59D9F2C8836}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SquirrelTests", "SquirrelTests\SquirrelTests.csproj", "{CC02A7DA-AA53-4D19-BB16-4DDA5243EB33}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SquirrelBusinessLogic", "SquirrelBusinessLogic\SquirrelBusinessLogic.csproj", "{C03D0604-CD06-42DA-99CB-23B8306C3714}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SquirrelDatabase", "SquirrelDatabase\SquirrelDatabase.csproj", "{A8A7A434-A278-4362-8D34-C2E3CAA938C1}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -15,6 +21,18 @@ Global
 		{3B0E65D7-E64B-4893-803B-A59D9F2C8836}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{3B0E65D7-E64B-4893-803B-A59D9F2C8836}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3B0E65D7-E64B-4893-803B-A59D9F2C8836}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CC02A7DA-AA53-4D19-BB16-4DDA5243EB33}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CC02A7DA-AA53-4D19-BB16-4DDA5243EB33}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CC02A7DA-AA53-4D19-BB16-4DDA5243EB33}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CC02A7DA-AA53-4D19-BB16-4DDA5243EB33}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C03D0604-CD06-42DA-99CB-23B8306C3714}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C03D0604-CD06-42DA-99CB-23B8306C3714}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C03D0604-CD06-42DA-99CB-23B8306C3714}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C03D0604-CD06-42DA-99CB-23B8306C3714}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A8A7A434-A278-4362-8D34-C2E3CAA938C1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A8A7A434-A278-4362-8D34-C2E3CAA938C1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A8A7A434-A278-4362-8D34-C2E3CAA938C1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A8A7A434-A278-4362-8D34-C2E3CAA938C1}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

SquirrelContract/SquirrelContract/BusinessLogicContracts/IClientBusinessLogicContract.cs

@@ -0,0 +1,16 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.BusinessLogicContracts;
+
+public interface IClientBusinessLogicContract
+{
+    List<ClientDataModel> GetAllClients();
+
+    ClientDataModel GetClientByData(string data);
+
+    void InsertClient(ClientDataModel clientDataModel);
+
+    void UpdateClient(ClientDataModel clientDataModel);
+
+    void DeleteClient(string id);
+}

SquirrelContract/SquirrelContract/BusinessLogicContracts/ICocktailBusinessLogicContract.cs

@@ -0,0 +1,18 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.BusinessLogicContracts;
+
+public interface ICocktailBusinessLogicContract
+{
+    List<CocktailDataModel> GetAllCocktails();
+
+    List<CocktailHistoryDataModel> GetCocktailHistoryByCocktail(string productId);
+
+    CocktailDataModel GetCocktailByData(string data);
+
+    void InsertCocktail(CocktailDataModel cocktailDataModel);
+
+    void UpdateCocktail(CocktailDataModel cocktailDataModel);
+
+    void DeleteCocktail(string id);
+}

SquirrelContract/SquirrelContract/BusinessLogicContracts/IEmployeeBusinessLogicContract.cs

@@ -0,0 +1,22 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.BusinessLogicContracts;
+
+public interface IEmployeeBusinessLogicContract
+{
+    List<EmployeeDataModel> GetAllEmployees(bool onlyActive = true);
+
+    List<EmployeeDataModel> GetAllEmployeesByPost(string employeeId, bool onlyActive = true);
+
+    List<EmployeeDataModel> GetAllEmployeesByBirthDate(DateTime fromDate, DateTime toDate, bool onlyActive = true);
+
+    List<EmployeeDataModel> GetAllEmployeesByEmploymentDate(DateTime fromDate, DateTime toDate, bool onlyActive = true);
+
+    EmployeeDataModel GetEmployeeByData(string data);
+
+    void InsertEmployee(EmployeeDataModel employeeDataModel);
+
+    void UpdateEmployee(EmployeeDataModel employeeDataModel);
+
+    void DeleteEmployee(string id);
+}

SquirrelContract/SquirrelContract/BusinessLogicContracts/IPostBusinessLogicContract.cs

@@ -0,0 +1,20 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.BusinessLogicContracts;
+
+public interface IPostBusinessLogicContract
+{
+    List<PostDataModel> GetAllPosts(bool onlyActive);
+
+    List<PostDataModel> GetAllDataOfPost(string postId);
+
+    PostDataModel GetPostByData(string data);
+
+    void InsertPost(PostDataModel postDataModel);
+
+    void UpdatePost(PostDataModel postDataModel);
+
+    void DeletePost(string id);
+
+    void RestorePost(string id);
+}

SquirrelContract/SquirrelContract/BusinessLogicContracts/ISalaryBusinessLogicContract.cs

@@ -0,0 +1,12 @@
+using BarBelochkaContract.DataModels;
+
+namespace SquirrelContract.BusinessLogicContracts;
+
+public interface ISalaryBusinessLogicContract
+{
+    List<SalaryDataModel> GetAllSalariesByPeriod(DateTime fromDate, DateTime toDate);
+
+    List<SalaryDataModel> GetAllSalariesByPeriodByEmployee(DateTime fromDate, DateTime toDate, string employeeId);
+
+    void CalculateSalaryByMounth(DateTime date);
+}

SquirrelContract/SquirrelContract/BusinessLogicContracts/ISaleBusinessLogicContract.cs

@@ -0,0 +1,20 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.BusinessLogicContracts;
+
+public interface ISaleBusinessLogicContract
+{
+    List<SaleDataModel> GetAllSalesByPeriod(DateTime fromDate, DateTime toDate);
+
+    List<SaleDataModel> GetAllSalesByEmployeeByPeriod(string employeeId, DateTime fromDate, DateTime toDate);
+
+    List<SaleDataModel> GetAllSalesByClientByPeriod(string clientId, DateTime fromDate, DateTime toDate);
+
+    List<SaleDataModel> GetAllSalesByCocktailByPeriod(string cocktailId, DateTime fromDate, DateTime toDate);
+
+    SaleDataModel GetSaleByData(string data);
+
+    void InsertSale(SaleDataModel saleDataModel);
+
+    void CancelSale(string id);
+}

SquirrelContract/SquirrelContract/DataModels/ClientDataModel.cs

@@ -0,0 +1,32 @@
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+using System.Text.RegularExpressions;
+
+namespace SquirrelContract.DataModels;
+
+public class ClientDataModel(string id, string fio, string phoneNumber, double discountSize) : IValidation
+{
+    public string Id { get; private set; } = id;
+    public string FIO { get; private set;} = fio;
+    public string PhoneNumber { get; private set;} = phoneNumber;
+    public double DiscountSize { get; private set; } = discountSize;
+
+    public void Validate()
+    {
+        if (Id.IsEmpty())
+            throw new ValidationException("Field Id is empty");
+
+        if (!Id.IsGuid())
+            throw new ValidationException("The value in the field Id is not a unique identifier");
+
+        if (FIO.IsEmpty())
+            throw new ValidationException("Field FIO is empty");
+
+        if (PhoneNumber.IsEmpty())
+            throw new ValidationException("Field PhoneNumber is empty");
+
+        if (!Regex.IsMatch(PhoneNumber, @"^((8|\+7)[\- ]?)?(\(?\d{3}\)?[\- ]?)?[\d\- ]{7,10}$"))
+            throw new ValidationException("Field PhoneNumber is not a phone number");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/CocktailDataModel.cs

@@ -0,0 +1,32 @@
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+
+namespace SquirrelContract.DataModels;
+
+public class CocktailDataModel(string id, string cocktailName, double price, AlcoholType baseAlcohol) : IValidation
+{
+    public string Id { get; private set; } = id;
+    public string CocktailName { get; private set; } = cocktailName;
+    public double Price { get; private set; } = price;
+    public AlcoholType BaseAlcohol { get; private set; } = baseAlcohol;
+
+    public void Validate()
+    {
+        if (Id.IsEmpty())
+            throw new ValidationException("Field Id is empty");
+
+        if (!Id.IsGuid())
+            throw new ValidationException("The value in the field Id is not a unique identifier");
+
+        if (CocktailName.IsEmpty())
+            throw new ValidationException("Field CocktailName is empty");
+
+        if (Price <= 0)
+            throw new ValidationException("Field Price is less than or equal to 0");
+
+        if (BaseAlcohol == AlcoholType.None)
+            throw new ValidationException("Field BaseAlcohol is empty");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/CocktailHistoryDataModel.cs

@@ -0,0 +1,26 @@
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+
+namespace SquirrelContract.DataModels;
+
+public class CocktailHistoryDataModel(string cocktailId, double oldPrice) : IValidation
+{
+    public string CocktailId { get; private set; } = cocktailId;
+
+    public double OldPrice { get; private set; } = oldPrice;
+
+    public DateTime ChangeDate { get; private set; } = DateTime.UtcNow;
+
+    public void Validate()
+    {
+        if (CocktailId.IsEmpty())
+            throw new ValidationException("Field CocktailId is empty");
+
+        if (!CocktailId.IsGuid())
+            throw new ValidationException("The value in the field CocktailId is not a unique identifier");
+
+        if (OldPrice <= 0)
+            throw new ValidationException("Field OldPrice is less than or equal to 0");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/EmployeeDataModel.cs

@@ -0,0 +1,56 @@
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+using System.Text.RegularExpressions;
+
+namespace SquirrelContract.DataModels;
+
+public class EmployeeDataModel(string id, string fio, string email, string postId, DateTime birthDate, DateTime employmentDate, bool isDeleted) : IValidation
+{
+    public string Id { get; private set; } = id;
+
+    public string FIO { get; private set; } = fio;
+
+    public string Email { get; private set; } = email;
+
+    public string PostId { get; private set; } = postId;
+
+    public DateTime BirthDate { get; private set; } = birthDate;
+
+    public DateTime EmploymentDate { get; private set; } = employmentDate;
+
+    public bool IsDeleted { get; private set; } = isDeleted;
+
+    public void Validate()
+    {
+        if (Id.IsEmpty())
+            throw new ValidationException("Field Id is empty");
+
+        if (!Id.IsGuid())
+            throw new ValidationException("The value in the field Id is not a unique identifier");
+
+        if (FIO.IsEmpty())
+            throw new ValidationException("Field FIO is empty");
+
+        if (Email.IsEmpty())
+            throw new ValidationException("Field Email is empty");
+
+        if (!Regex.IsMatch(Email, @"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"))
+            throw new ValidationException("Field Email is not a valid email address");
+
+        if (PostId.IsEmpty())
+            throw new ValidationException("Field PostId is empty");
+
+        if (!PostId.IsGuid())
+            throw new ValidationException("The value in the field PostId is not a unique identifier");
+
+        if (BirthDate.Date > DateTime.Now.AddYears(-18).Date)
+            throw new ValidationException($"Only adults can be hired (BirthDate = {BirthDate.ToShortDateString()})");
+
+        if (EmploymentDate.Date < BirthDate.Date)
+            throw new ValidationException("The date of employment cannot be less than the date of birth");
+
+        if ((EmploymentDate - BirthDate).TotalDays / 365 < 18) // EmploymentDate.Year - BirthDate.Year
+            throw new ValidationException($"Only adults can be hired (EmploymentDate - {EmploymentDate.ToShortDateString()}, BirthDate - {BirthDate.ToShortDateString()})");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/PostDataModel.cs

@@ -0,0 +1,39 @@
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+
+namespace SquirrelContract.DataModels;
+
+public class PostDataModel(string postId, string postName, PostType postType, double salary, bool isActual, DateTime changeDate) : IValidation
+{
+    public string Id { get; private set; } = postId;
+
+    public string PostName { get; private set; } = postName;
+
+    public PostType PostType { get; private set; } = postType;
+
+    public double Salary { get; private set; } = salary;
+
+    public bool IsActual { get; private set; } = isActual;
+
+    public DateTime ChangeDate { get; private set; } = changeDate;
+
+    public void Validate()
+    {
+        if (Id.IsEmpty())
+            throw new ValidationException("Field Id is empty");
+
+        if (!Id.IsGuid())
+            throw new ValidationException("The value in the field Id is not a unique identifier");
+
+        if (PostName.IsEmpty())
+            throw new ValidationException("Field PostName is empty");
+
+        if (PostType == PostType.None)
+            throw new ValidationException("Field PostType is empty");
+
+        if (Salary <= 0)
+            throw new ValidationException("Field Salary is empty");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/SalaryDataModel.cs

@@ -0,0 +1,26 @@
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+
+namespace BarBelochkaContract.DataModels;
+
+public class SalaryDataModel(string employeeId, DateTime salaryDate, double employeeSalary) : IValidation
+{
+    public string EmployeeId { get; private set; } = employeeId;
+
+    public DateTime SalaryDate { get; private set; } = salaryDate;
+
+    public double Salary { get; private set; } = employeeSalary;
+
+    public void Validate()
+    {
+        if (EmployeeId.IsEmpty())
+            throw new ValidationException("Field EmployeeId is empty");
+
+        if (!EmployeeId.IsGuid())
+            throw new ValidationException("The value in the field EmployeeId is not a unique identifier");
+
+        if (Salary <= 0)
+            throw new ValidationException("Field Salary is less than or equal to 0");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/SaleCocktailDataModel.cs

@@ -0,0 +1,32 @@
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+
+namespace SquirrelContract.DataModels;
+
+public class SaleCocktailDataModel(string saleId, string cocktailId, int count) : IValidation
+{
+    public string SaleId { get; private set; } = saleId;
+
+    public string CocktailId { get; private set; } = cocktailId;
+
+    public int Count { get; private set; } = count;
+
+    public void Validate()
+    {
+        if (SaleId.IsEmpty())
+            throw new ValidationException("Field SaleId is empty");
+
+        if (!SaleId.IsGuid())
+            throw new ValidationException("The value in the field SaleId is not a unique identifier");
+
+        if (CocktailId.IsEmpty())
+            throw new ValidationException("Field ProductId is empty");
+
+        if (!CocktailId.IsGuid())
+            throw new ValidationException("The value in the field ProductId is not a unique identifier");
+
+        if (Count <= 0)
+            throw new ValidationException("Field Count is less than or equal to 0");
+    }
+}

SquirrelContract/SquirrelContract/DataModels/SaleDataModel.cs

@@ -0,0 +1,51 @@
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.Extensions;
+using SquirrelContract.Infastructure;
+
+namespace SquirrelContract.DataModels;
+
+public class SaleDataModel(string id, string employeeId, string? clientId, double sum, DiscountType discountType, double discount, bool isCancel, List<SaleCocktailDataModel> saleCocktails) : IValidation
+{
+    public string Id { get; private set; } = id;
+
+    public string EmployeeId { get; private set; } = employeeId;
+
+    public string? ClientId { get; private set; } = clientId;
+
+    public DateTime SaleDate { get; private set; } = DateTime.UtcNow;
+
+    public double Sum { get; private set; } = sum;
+
+    public DiscountType DiscountType { get; private set; } = discountType;
+
+    public double Discount { get; private set; } = discount;
+    
+    public bool IsCancel { get; private set; } = isCancel;
+
+    public List<SaleCocktailDataModel> Cocktails { get; private set; } = saleCocktails;
+
+    public void Validate()
+    {
+        if (Id.IsEmpty())
+            throw new ValidationException("Field Id is empty");
+
+        if (!Id.IsGuid())
+            throw new ValidationException("The value in the field Id is not a unique identifier");
+
+        if (EmployeeId.IsEmpty())
+            throw new ValidationException("Field EmployeeId is empty");
+
+        if (!EmployeeId.IsGuid())
+            throw new ValidationException("The value in the field EmployeeId is not a unique identifier");
+
+        if (!ClientId?.IsGuid() ?? !ClientId?.IsEmpty() ?? false)
+            throw new ValidationException("The value in the field BuyerId is not a unique identifier");
+
+        if (Sum <= 0)
+            throw new ValidationException("Field Sum is less than or equal to 0");
+
+        if ((Cocktails?.Count ?? 0) == 0)
+            throw new ValidationException("The sale must include cocktails");
+    }
+}

SquirrelContract/SquirrelContract/Enums/AlcoholType.cs

@@ -0,0 +1,10 @@
+namespace SquirrelContract.Enums;
+
+public enum AlcoholType
+{
+    None = 0,
+    Vodka = 1, 
+    Whiskey = 2,
+    Wine = 3,
+    Beer = 4
+}

SquirrelContract/SquirrelContract/Enums/DiscountType.cs

@@ -0,0 +1,10 @@
+namespace SquirrelContract.Enums;
+
+[Flags]
+public enum DiscountType
+{
+    None = 0,
+    OnSale = 1,
+    RegularCustomer = 2,
+    Certificate = 4
+}

SquirrelContract/SquirrelContract/Enums/PostType.cs

@@ -0,0 +1,9 @@
+namespace SquirrelContract.Enums;
+
+public enum PostType
+{
+    None = 0,
+    Bartender = 1,
+    Manager = 2,
+    PurchasingSpecialist = 3
+}

SquirrelContract/SquirrelContract/Exceptions/ElementDeletedException.cs

@@ -0,0 +1,6 @@
+namespace SquirrelContract.Exceptions;
+
+public class ElementDeletedException : Exception
+{
+	public ElementDeletedException(string id) : base($"Cannot modify a deleted item (id: {id})") { }
+}

SquirrelContract/SquirrelContract/Exceptions/ElementNotFoundException.cs

@@ -0,0 +1,11 @@
+namespace SquirrelContract.Exceptions;
+
+public class ElementNotFoundException : Exception
+{
+    public string Value { get; private set; }
+
+    public ElementNotFoundException(string value) : base($"Element not found at value = {value}")
+    {
+        Value = value;
+    }
+}

SquirrelContract/SquirrelContract/Exceptions/ExceptionExistException.cs

@@ -0,0 +1,14 @@
+namespace SquirrelContract.Exceptions;
+
+public class ElementExistsException : Exception
+{
+    public string ParamName { get; private set; }
+
+    public string ParamValue { get; private set; }
+
+    public ElementExistsException(string paramName, string paramValue) : base($"There is already an element with value{paramValue} of parameter {paramName}")
+    {
+        ParamName = paramName;
+        ParamValue = paramValue;
+    }
+}

SquirrelContract/SquirrelContract/Exceptions/IncorrectDatesException.cs

@@ -0,0 +1,6 @@
+namespace SquirrelContract.Exceptions;
+
+public class IncorrectDatesException : Exception
+{
+    public IncorrectDatesException(DateTime start, DateTime end) : base($"The end date must be later than the start date.. StartDate: {start:dd.MM.YYYY}. EndDate: {end:dd.MM.YYYY}") { }
+}

SquirrelContract/SquirrelContract/Exceptions/NullListException.cs

@@ -0,0 +1,6 @@
+namespace SquirrelContract.Exceptions;
+
+public class NullListException : Exception
+{
+    public NullListException() : base("The returned list is null") { }
+}

SquirrelContract/SquirrelContract/Exceptions/StorageException.cs

@@ -0,0 +1,6 @@
+namespace SquirrelContract.Exceptions;
+
+public class StorageException : Exception
+{
+    public StorageException(Exception ex) : base($"Error while working in storage: {ex.Message}", ex) { }
+}

SquirrelContract/SquirrelContract/Exceptions/ValidationException.cs

@@ -0,0 +1,5 @@
+namespace SquirrelContract.Exceptions;
+
+public class ValidationException(string message) : Exception(message)
+{
+}

SquirrelContract/SquirrelContract/Extensions/DateTimeExtensions.cs

@@ -0,0 +1,9 @@
+namespace SquirrelContract.Extensions;
+
+public static class DateTimeExtensions
+{
+    public static bool IsDateNotOlder(this DateTime date, DateTime olderDate)
+    {
+        return date >= olderDate;
+    }
+}

SquirrelContract/SquirrelContract/Extensions/StringExtensions.cs

@@ -0,0 +1,14 @@
+namespace SquirrelContract.Extensions;
+
+public static class StringExtensions
+{
+    public static bool IsEmpty(this string str)
+    {
+        return string.IsNullOrWhiteSpace(str);
+    }
+
+    public static bool IsGuid(this string str)
+    {
+        return Guid.TryParse(str, out _);
+    }
+}

SquirrelContract/SquirrelContract/Infastructure/IConfigurationDatabase.cs

@@ -0,0 +1,6 @@
+namespace SquirrelContract.Infastructure;
+
+public interface IConfigurationDatabase
+{
+    string ConnectionString { get; }
+}

SquirrelContract/SquirrelContract/Infastructure/IValidation.cs

@@ -0,0 +1,6 @@
+namespace SquirrelContract.Infastructure;
+
+public interface IValidation
+{
+    void Validate();
+}

SquirrelContract/SquirrelContract/StoragesContracts/IClientStorageContract.cs

@@ -0,0 +1,20 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.StoragesContracts;
+
+public interface IClientStorageContract
+{
+    List<ClientDataModel> GetList();
+
+    ClientDataModel? GetElementById(string id);
+
+    ClientDataModel? GetElementByPhoneNumber(string phoneNumber);
+
+    ClientDataModel? GetElementByFIO(string fio);
+
+    void AddElement(ClientDataModel clientDataModel);
+
+    void UpdElement(ClientDataModel clientDataModel);
+
+    void DelElement(string id);
+}

SquirrelContract/SquirrelContract/StoragesContracts/ICocktailStorageContract.cs

@@ -0,0 +1,15 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.StoragesContracts;
+
+public interface ICocktailStorageContract
+{
+    List<CocktailDataModel> GetList();
+    List<CocktailHistoryDataModel> GetHistoryByCocktailId(string cocktailId);
+    CocktailDataModel? GetElementById(string id);
+    CocktailDataModel? GetElementByName(string name);
+    void AddElement(CocktailDataModel cocktailDataModel);
+    void UpdElement(CocktailDataModel cocktailDataModel);
+    void DelElement(string id);
+    void ResElement(string id);
+}

SquirrelContract/SquirrelContract/StoragesContracts/IEmployeeStorageContract.cs

@@ -0,0 +1,20 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.StoragesContracts;
+
+public interface IEmployeeStorageContract
+{
+    List<EmployeeDataModel> GetList(bool onlyActive = true, string? postId = null, DateTime? fromBirthDate = null, DateTime? toBirthDate = null, DateTime? fromEmploymentDate = null, DateTime? toEmploymentDate = null);
+
+    EmployeeDataModel? GetElementById(string id);
+
+    EmployeeDataModel? GetElementByFIO(string fio);
+
+    EmployeeDataModel? GetElementByEmail(string email);
+
+    void AddElement(EmployeeDataModel employeeDataModel);
+
+    void UpdElement(EmployeeDataModel employeeDataModel);
+
+    void DelElement(string id);
+}

SquirrelContract/SquirrelContract/StoragesContracts/IPostStorageContract.cs

@@ -0,0 +1,15 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.StoragesContracts;
+
+public interface IPostStorageContract
+{
+    List<PostDataModel> GetList(bool onlyActual = true);
+    List<PostDataModel> GetPostWithHistory(string postId);
+    PostDataModel? GetElementById(string id);
+    PostDataModel? GetElementByName(string name);
+    void AddElement(PostDataModel postDataModel);
+    void UpdElement(PostDataModel postDataModel);
+    void DelElement(string id);
+    void ResElement(string id);
+}

SquirrelContract/SquirrelContract/StoragesContracts/ISalaryStorageContract.cs

@@ -0,0 +1,10 @@
+using BarBelochkaContract.DataModels;
+
+namespace SquirrelContract.StoragesContracts;
+
+public interface ISalaryStorageContract
+{
+    List<SalaryDataModel> GetList(DateTime startDate, DateTime endDate, string? employeeId = null);
+
+    void AddElement(SalaryDataModel salaryDataModel);
+}

SquirrelContract/SquirrelContract/StoragesContracts/ISaleStorageContract.cs

@@ -0,0 +1,14 @@
+using SquirrelContract.DataModels;
+
+namespace SquirrelContract.StoragesContracts;
+
+public interface ISaleStorageContract
+{
+    List<SaleDataModel> GetList(DateTime? startDate = null, DateTime? endDate = null, string? employeeId = null, string? clientId = null, string? cocktailId = null);
+
+    SaleDataModel? GetElementById(string id);
+
+    void AddElement(SaleDataModel saleDataModel);
+
+    void DelElement(string id);
+}

SquirrelContract/SquirrelDatabase/Implementations/ClientStorageContract.cs

@@ -0,0 +1,149 @@
+using AutoMapper;
+using Microsoft.EntityFrameworkCore;
+using Npgsql;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Models;
+using System;
+
+namespace SquirrelDatabase.Implementations;
+
+public class ClientStorageContract : IClientStorageContract
+{
+    private readonly SquirrelDbContext _dbContext;
+    private readonly Mapper _mapper;
+
+    public ClientStorageContract(SquirrelDbContext squirrelDbContext)
+    {
+        _dbContext = squirrelDbContext;
+        var config = new MapperConfiguration(cfg =>
+        {
+            cfg.AddMaps(typeof(SquirrelDbContext).Assembly);
+        });
+        _mapper = new Mapper(config);
+    }
+
+    public List<ClientDataModel> GetList()
+    {
+        try
+        {
+            return [.. _dbContext.Clients.Select(x => _mapper.Map<ClientDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public ClientDataModel? GetElementById(string id)
+    {
+        try
+        {
+            return _mapper.Map<ClientDataModel>(GetClientById(id));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public ClientDataModel? GetElementByFIO(string fio)
+    {
+        try
+        {
+            return _mapper.Map<ClientDataModel>(_dbContext.Clients.FirstOrDefault(x => x.FIO == fio));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public ClientDataModel? GetElementByPhoneNumber(string phoneNumber)
+    {
+        try
+        {
+            return _mapper.Map<ClientDataModel>(_dbContext.Clients.FirstOrDefault(x => x.PhoneNumber == phoneNumber));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void AddElement(ClientDataModel clientDataModel)
+    {
+        try
+        {
+            _dbContext.Clients.Add(_mapper.Map<Client>(clientDataModel));
+            _dbContext.SaveChanges();
+        }
+        catch (InvalidOperationException ex) when (ex.TargetSite?.Name == "ThrowIdentityConflict")
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("Id", clientDataModel.Id);
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Clients_PhoneNumber" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("PhoneNumber", clientDataModel.PhoneNumber);
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void UpdElement(ClientDataModel clientDataModel)
+    {
+        try
+        {
+            var element = GetClientById(clientDataModel.Id) ?? throw new ElementNotFoundException(clientDataModel.Id);
+            _dbContext.Clients.Update(_mapper.Map(clientDataModel, element));
+            _dbContext.SaveChanges();
+        }
+        catch (ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Clients_PhoneNumber" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("PhoneNumber", clientDataModel.PhoneNumber);
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void DelElement(string id)
+    {
+        try
+        {
+            var element = GetClientById(id) ?? throw new ElementNotFoundException(id);
+            _dbContext.Clients.Remove(element);
+            _dbContext.SaveChanges();
+        }
+        catch (ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    private Client? GetClientById(string id) => _dbContext.Clients.FirstOrDefault(x => x.Id == id);
+}

SquirrelContract/SquirrelDatabase/Implementations/CocktailStorageContract.cs

@@ -0,0 +1,164 @@
+using AutoMapper;
+using Microsoft.EntityFrameworkCore;
+using Npgsql;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Models;
+
+namespace SquirrelDatabase.Implementations;
+
+public class CocktailStorageContract : ICocktailStorageContract
+{
+    private readonly SquirrelDbContext _dbContext;
+    private readonly Mapper _mapper;
+
+    public CocktailStorageContract(SquirrelDbContext dbContext)
+    {
+        _dbContext = dbContext;
+        var config = new MapperConfiguration(cfg =>
+        {
+            cfg.CreateMap<Cocktail, CocktailDataModel>();
+            cfg.CreateMap<CocktailDataModel, Cocktail>();
+            cfg.CreateMap<CocktailHistory, CocktailHistoryDataModel>();
+        });
+        _mapper = new Mapper(config);
+    }
+
+    public List<CocktailDataModel> GetList()
+    {
+        try
+        {
+            return [.. _dbContext.Cocktails.Select(x => _mapper.Map<CocktailDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public List<CocktailHistoryDataModel> GetHistoryByCocktailId(string cocktailId)
+    {
+        try
+        {
+            return [.. _dbContext.CocktailHistories.Where(x => x.CocktailId == cocktailId).OrderByDescending(x => x.ChangeDate).Select(x => _mapper.Map<CocktailHistoryDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public CocktailDataModel? GetElementById(string id)
+    {
+        try
+        {
+            return _mapper.Map<CocktailDataModel>(GetCocktailById(id));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public CocktailDataModel? GetElementByName(string name)
+    {
+        try
+        {
+            return _mapper.Map<CocktailDataModel>(_dbContext.Cocktails.FirstOrDefault(x => x.CocktailName == name));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void AddElement(CocktailDataModel cocktailDataModel)
+    {
+        try
+        {
+            _dbContext.Cocktails.Add(_mapper.Map<Cocktail>(cocktailDataModel));
+            _dbContext.SaveChanges();
+        }
+        catch (InvalidOperationException ex) when (ex.TargetSite?.Name == "ThrowIdentityConflict")
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("Id", cocktailDataModel.Id);
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Cocktails_CocktailName" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("CocktailName", cocktailDataModel.CocktailName);
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void UpdElement(CocktailDataModel cocktailDataModel)
+    {
+        try
+        {
+            var element = GetCocktailById(cocktailDataModel.Id) ?? throw new ElementNotFoundException(cocktailDataModel.Id);
+            _dbContext.Cocktails.Update(_mapper.Map(cocktailDataModel, element));
+            _dbContext.SaveChanges();
+        }
+        catch (ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Cocktails_CocktailName" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("CocktailName", cocktailDataModel.CocktailName);
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void DelElement(string id)
+    {
+        try
+        {
+            var element = GetCocktailById(id) ?? throw new ElementNotFoundException(id);
+            _dbContext.Cocktails.Remove(element);
+            _dbContext.SaveChanges();
+        }
+        catch (ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void ResElement(string id)
+    {
+        try
+        {
+            var element = GetCocktailById(id) ?? throw new ElementNotFoundException(id);
+            _dbContext.SaveChanges();
+        }
+        catch
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+    }
+
+    private Cocktail? GetCocktailById(string id) => _dbContext.Cocktails.FirstOrDefault(x => x.Id == id);
+}

SquirrelContract/SquirrelDatabase/Implementations/EmployeeStorageContract.cs

@@ -0,0 +1,153 @@
+using AutoMapper;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Models;
+
+namespace SquirrelDatabase.Implementations;
+
+public class EmployeeStorageContract : IEmployeeStorageContract
+{
+    private readonly SquirrelDbContext _dbContext;
+    private readonly Mapper _mapper;
+
+    public EmployeeStorageContract(SquirrelDbContext dbContext)
+    {
+        _dbContext = dbContext;
+        var config = new MapperConfiguration(cfg =>
+        {
+            cfg.AddMaps(typeof(SquirrelDbContext).Assembly);
+        });
+        _mapper = new Mapper(config);
+    }
+
+    public List<EmployeeDataModel> GetList(bool onlyActive = true, string? postId = null, DateTime? fromBirthDate = null, DateTime? toBirthDate = null, DateTime? fromEmploymentDate = null, DateTime? toEmploymentDate = null)
+    {
+        try
+        {
+            var query = _dbContext.Employees.AsQueryable();
+            if (onlyActive)
+            {
+                query = query.Where(x => !x.IsDeleted);
+            }
+            if (postId is not null)
+            {
+                query = query.Where(x => x.PostId == postId);
+            }
+            if (fromBirthDate is not null && toBirthDate is not null)
+            {
+                query = query.Where(x => x.BirthDate >= fromBirthDate && x.BirthDate <= toBirthDate);
+            }
+            if (fromEmploymentDate is not null && toEmploymentDate is not null)
+            {
+                query = query.Where(x => x.EmploymentDate >= fromEmploymentDate && x.EmploymentDate <= toEmploymentDate);
+            }
+            return [.. query.Select(x => _mapper.Map<EmployeeDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public EmployeeDataModel? GetElementById(string id)
+    {
+        try
+        {
+            return _mapper.Map<EmployeeDataModel>(GetEmployeeById(id));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public EmployeeDataModel? GetElementByFIO(string fio)
+    {
+        try
+        {
+            return _mapper.Map<EmployeeDataModel>(_dbContext.Employees.FirstOrDefault(x => x.FIO == fio));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public EmployeeDataModel? GetElementByEmail(string email)
+    {
+        try
+        {
+            return _mapper.Map<EmployeeDataModel>(_dbContext.Employees.FirstOrDefault(x => x.Email == email));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void AddElement(EmployeeDataModel employeeDataModel)
+    {
+        try
+        {
+            _dbContext.Employees.Add(_mapper.Map<Employee>(employeeDataModel));
+            _dbContext.SaveChanges();
+        }
+        catch (InvalidOperationException ex) when (ex.TargetSite?.Name == "ThrowIdentityConflict")
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("Id", employeeDataModel.Id);
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void UpdElement(EmployeeDataModel employeeDataModel)
+    {
+        try
+        {
+            var element = GetEmployeeById(employeeDataModel.Id) ?? throw new ElementNotFoundException(employeeDataModel.Id);
+            _dbContext.Employees.Update(_mapper.Map(employeeDataModel, element));
+            _dbContext.SaveChanges();
+        }
+        catch (ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void DelElement(string id)
+    {
+        try
+        {
+            var element = GetEmployeeById(id) ?? throw new ElementNotFoundException(id);
+            element.IsDeleted = true;
+            _dbContext.SaveChanges();
+        }
+        catch (ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    private Employee? GetEmployeeById(string id) => _dbContext.Employees.FirstOrDefault(x => x.Id == id && !x.IsDeleted);
+}

SquirrelContract/SquirrelDatabase/Implementations/PostStorageContract.cs

@@ -0,0 +1,190 @@
+using AutoMapper;
+using Microsoft.EntityFrameworkCore;
+using Npgsql;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Models;
+
+namespace SquirrelDatabase.Implementations;
+
+public class PostStorageContract : IPostStorageContract
+{
+    private readonly SquirrelDbContext _dbContext;
+    private readonly Mapper _mapper;
+
+    public PostStorageContract(SquirrelDbContext dbContext)
+    {
+        _dbContext = dbContext;
+        var config = new MapperConfiguration(cfg =>
+        {
+            cfg.CreateMap<Post, PostDataModel>()
+                .ForMember(x => x.Id, x => x.MapFrom(src => src.PostId));
+            cfg.CreateMap<PostDataModel, Post>()
+                .ForMember(x => x.Id, x => x.Ignore())
+                .ForMember(x => x.PostId, x => x.MapFrom(src => src.Id))
+                .ForMember(x => x.IsActual, x => x.MapFrom(src => true))
+                .ForMember(x => x.ChangeDate, x => x.MapFrom(src => DateTime.UtcNow));
+        });
+        _mapper = new Mapper(config);
+    }
+
+    public List<PostDataModel> GetList(bool onlyActual = true)
+    {
+        try
+        {
+            var query = _dbContext.Posts.AsQueryable();
+            if (onlyActual)
+            {
+                query = query.Where(x => x.IsActual);
+            }
+            return [.. query.Select(x => _mapper.Map<PostDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public List<PostDataModel> GetPostWithHistory(string postId)
+    {
+        try
+        {
+            return [.. _dbContext.Posts.Where(x => x.PostId == postId).Select(x => _mapper.Map<PostDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public PostDataModel? GetElementById(string id)
+    {
+        try
+        {
+            return _mapper.Map<PostDataModel>(_dbContext.Posts.FirstOrDefault(x => x.PostId == id && x.IsActual));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public PostDataModel? GetElementByName(string name)
+    {
+        try
+        {
+            return _mapper.Map<PostDataModel>(_dbContext.Posts.FirstOrDefault(x => x.PostName == name && x.IsActual));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void AddElement(PostDataModel postDataModel)
+    {
+        try
+        {
+            _dbContext.Posts.Add(_mapper.Map<Post>(postDataModel));
+            _dbContext.SaveChanges();
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Posts_PostName_IsActual" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("PostName", postDataModel.PostName);
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Posts_PostId_IsActual" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("PostId", postDataModel.Id);
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void UpdElement(PostDataModel postDataModel)
+    {
+        try
+        {
+            var transaction = _dbContext.Database.BeginTransaction();
+            try
+            {
+                var element = GetPostById(postDataModel.Id) ?? throw new ElementNotFoundException(postDataModel.Id);
+                if (!element.IsActual)
+                {
+                    throw new ElementDeletedException(postDataModel.Id);
+                }
+                element.IsActual = false;
+                _dbContext.SaveChanges();
+                var newElement = _mapper.Map<Post>(postDataModel);
+                _dbContext.Posts.Add(newElement);
+                _dbContext.SaveChanges();
+                transaction.Commit();
+            }
+            catch
+            {
+                transaction.Rollback();
+                throw;
+            }
+        }
+        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Posts_PostName_IsActual" })
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new ElementExistsException("PostName", postDataModel.PostName);
+        }
+        catch (Exception ex) when (ex is ElementDeletedException || ex is ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void DelElement(string id)
+    {
+        try
+        {
+            var element = GetPostById(id) ?? throw new ElementNotFoundException(id);
+            if (!element.IsActual)
+            {
+                throw new ElementDeletedException(id);
+            }
+            element.IsActual = false;
+            _dbContext.SaveChanges();
+        }
+        catch
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+    }
+
+    public void ResElement(string id)
+    {
+        try
+        {
+            var element = GetPostById(id) ?? throw new ElementNotFoundException(id);
+            element.IsActual = true;
+            _dbContext.SaveChanges();
+        }
+        catch
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+    }
+
+    private Post? GetPostById(string id) => _dbContext.Posts.Where(x => x.PostId == id).OrderByDescending(x => x.ChangeDate).FirstOrDefault();
+}

SquirrelContract/SquirrelDatabase/Implementations/SalaryStorageContract.cs

@@ -0,0 +1,57 @@
+using AutoMapper;
+using BarBelochkaContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Models;
+
+namespace SquirrelDatabase.Implementations;
+
+public class SalaryStorageContract : ISalaryStorageContract
+{
+    private readonly SquirrelDbContext _dbContext;
+    private readonly Mapper _mapper;
+
+    public SalaryStorageContract(SquirrelDbContext dbContext)
+    {
+        _dbContext = dbContext;
+        var config = new MapperConfiguration(cfg =>
+        {
+            cfg.CreateMap<Salary, SalaryDataModel>();
+            cfg.CreateMap<SalaryDataModel, Salary>()
+                .ForMember(dest => dest.EmployeeSalary, opt => opt.MapFrom(src => src.Salary));
+        });
+        _mapper = new Mapper(config);
+    }
+
+    public List<SalaryDataModel> GetList(DateTime startDate, DateTime endDate, string? employeeId = null)
+    {
+        try
+        {
+            var query = _dbContext.Salaries.Where(x => x.SalaryDate >= startDate && x.SalaryDate <= endDate);
+            if (employeeId is not null)
+            {
+                query = query.Where(x => x.EmployeeId == employeeId);
+            }
+            return [.. query.Select(x => _mapper.Map<SalaryDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void AddElement(SalaryDataModel salaryDataModel)
+    {
+        try
+        {
+            _dbContext.Salaries.Add(_mapper.Map<Salary>(salaryDataModel));
+            _dbContext.SaveChanges();
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+}

SquirrelContract/SquirrelDatabase/Implementations/SaleStorageContract.cs

@@ -0,0 +1,112 @@
+using AutoMapper;
+using Microsoft.EntityFrameworkCore;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Models;
+
+namespace SquirrelDatabase.Implementations;
+
+public class SaleStorageContract : ISaleStorageContract
+{
+    private readonly SquirrelDbContext _dbContext;
+    private readonly Mapper _mapper;
+
+    public SaleStorageContract(SquirrelDbContext dbContext)
+    {
+        _dbContext = dbContext;
+        var config = new MapperConfiguration(cfg =>
+        {
+            cfg.CreateMap<SaleCocktail, SaleCocktailDataModel>();
+            cfg.CreateMap<SaleCocktailDataModel, SaleCocktail>();
+            cfg.CreateMap<Sale, SaleDataModel>();
+            cfg.CreateMap<SaleDataModel, Sale>()
+                .ForMember(x => x.IsCancel, x => x.MapFrom(src => false))
+                .ForMember(x => x.SaleCocktails, x => x.MapFrom(src => src.Cocktails));
+        });
+        _mapper = new Mapper(config);
+    }
+
+    public List<SaleDataModel> GetList(DateTime? startDate = null, DateTime? endDate = null, string? employeeId = null, string? clientId = null, string? cocktailId = null)
+    {
+        try
+        {
+            var query = _dbContext.Sales.Include(x => x.SaleCocktails).AsQueryable();
+            if (startDate is not null && endDate is not null)
+            {
+                query = query.Where(x => x.SaleDate >= startDate && x.SaleDate < endDate);
+            }
+            if (employeeId is not null)
+            {
+                query = query.Where(x => x.EmployeeId == employeeId);
+            }
+            if (clientId is not null)
+            {
+                query = query.Where(x => x.ClientId == clientId);
+            }
+            if (cocktailId is not null)
+            {
+                query = query.Where(x => x.SaleCocktails!.Any(y => y.CocktailId == cocktailId));
+            }
+            return [.. query.Select(x => _mapper.Map<SaleDataModel>(x))];
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public SaleDataModel? GetElementById(string id)
+    {
+        try
+        {
+            return _mapper.Map<SaleDataModel>(GetSaleById(id));
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void AddElement(SaleDataModel saleDataModel)
+    {
+        try
+        {
+            _dbContext.Sales.Add(_mapper.Map<Sale>(saleDataModel));
+            _dbContext.SaveChanges();
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    public void DelElement(string id)
+    {
+        try
+        {
+            var element = GetSaleById(id) ?? throw new ElementNotFoundException(id);
+            if (element.IsCancel)
+            {
+                throw new ElementDeletedException(id);
+            }
+            element.IsCancel = true;
+            _dbContext.SaveChanges();
+        }
+        catch (Exception ex) when (ex is ElementDeletedException || ex is ElementNotFoundException)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _dbContext.ChangeTracker.Clear();
+            throw new StorageException(ex);
+        }
+    }
+
+    private Sale? GetSaleById(string id) => _dbContext.Sales.FirstOrDefault(x => x.Id == id);
+}

SquirrelContract/SquirrelDatabase/Models/Client.cs

@@ -0,0 +1,18 @@
+using AutoMapper;
+using SquirrelContract.DataModels;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace SquirrelDatabase.Models;
+
+[AutoMap(typeof(ClientDataModel), ReverseMap = true)]
+public class Client
+{
+    public required string Id { get; set; } = Guid.NewGuid().ToString();
+    public required string FIO { get; set; } 
+    public required string PhoneNumber { get; set; } 
+    public double DiscountSize { get; set; }
+
+    [ForeignKey("ClientId")]
+    public List<Sale>? Sales { get; set; }
+
+}

SquirrelContract/SquirrelDatabase/Models/Cocktail.cs

@@ -0,0 +1,18 @@
+using SquirrelContract.Enums;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace SquirrelDatabase.Models;
+
+public class Cocktail
+{
+    public required string Id { get; set; }
+    public required string CocktailName { get; set; }
+    public double Price { get; set; }
+    public required AlcoholType BaseAlcohol { get; set; }
+
+    [ForeignKey("CocktailId")]
+    public List<CocktailHistory>? CocktailHistories { get; set; }
+
+    [ForeignKey("CocktailId")]
+    public List<SaleCocktail>? SaleCocktails { get; set; }
+}

SquirrelContract/SquirrelDatabase/Models/CocktailHistory.cs

@@ -0,0 +1,14 @@
+namespace SquirrelDatabase.Models;
+
+public class CocktailHistory
+{
+    public string Id { get; set; } = Guid.NewGuid().ToString();
+
+    public required string CocktailId { get; set; }
+
+    public double OldPrice { get; set; }
+
+    public DateTime ChangeDate { get; set; }
+
+    public Cocktail? Cocktail { get; set; }
+}

SquirrelContract/SquirrelDatabase/Models/Employee.cs

@@ -0,0 +1,29 @@
+using AutoMapper;
+using SquirrelContract.DataModels;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace SquirrelDatabase.Models;
+
+[AutoMap(typeof(EmployeeDataModel), ReverseMap = true)]
+public class Employee
+{
+    public required string Id { get; set; }
+
+    public required string FIO { get; set; }
+
+    public string Email { get; set; }
+
+    public string PostId { get; set; }
+
+    public DateTime BirthDate { get; set; }
+
+    public DateTime EmploymentDate { get; set; }
+
+    public bool IsDeleted { get; set; }
+
+    [ForeignKey("EmployeeId")]
+    public List<Salary>? Salaries { get; set; }
+
+    [ForeignKey("EmployeeId")]
+    public List<Sale>? Sales { get; set; }
+}

SquirrelContract/SquirrelDatabase/Models/Post.cs

@@ -0,0 +1,22 @@
+using AutoMapper;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+
+namespace SquirrelDatabase.Models;
+
+public class Post
+{
+    public required string Id { get; set; } = Guid.NewGuid().ToString();
+
+    public required string PostId { get; set; }
+
+    public required string PostName { get; set; }
+
+    public PostType PostType { get; set; }
+
+    public double Salary { get; set; }
+
+    public bool IsActual { get; set; }
+
+    public DateTime ChangeDate { get; set; }
+}

SquirrelContract/SquirrelDatabase/Models/Salary.cs

@@ -0,0 +1,18 @@
+using AutoMapper;
+using BarBelochkaContract.DataModels;
+
+namespace SquirrelDatabase.Models;
+
+public class Salary
+{
+    public string Id { get; set; } = Guid.NewGuid().ToString();
+
+    public required string EmployeeId { get; set; }
+
+    public DateTime SalaryDate { get; set; }
+
+    public double EmployeeSalary { get; set; }
+
+    public Employee? Employee { get; set; }
+
+}

SquirrelContract/SquirrelDatabase/Models/Sale.cs

@@ -0,0 +1,33 @@
+using AutoMapper;
+using BarBelochkaContract.DataModels;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace SquirrelDatabase.Models;
+
+public class Sale
+{
+    public string Id { get; set; } = Guid.NewGuid().ToString();
+
+    public required string EmployeeId { get; set; }
+
+    public string? ClientId { get; set; }
+
+    public DateTime SaleDate { get; set; }
+
+    public double Sum { get; set; }
+
+    public DiscountType DiscountType { get; set; }
+
+    public double Discount { get; set; }
+
+    public bool IsCancel { get; set; }
+
+    public Employee? Employee { get; set; }  
+
+    public Client? Client { get; set; }
+
+    [ForeignKey("SaleId")]
+    public List<SaleCocktail>? SaleCocktails { get; set; }
+}

SquirrelContract/SquirrelDatabase/Models/SaleCocktail.cs

@@ -0,0 +1,10 @@
+namespace SquirrelDatabase.Models;
+
+public class SaleCocktail
+{
+    public required string SaleId { get; set; }
+
+    public required string CocktailId { get; set; }
+
+    public int Count { get; set; }
+}

SquirrelContract/SquirrelDatabase/SquirrelDatabase.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Library</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="AutoMapper" Version="14.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.2" />
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.3" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\SquirrelContract\SquirrelContract.csproj" />
+  </ItemGroup>
+
+</Project>

SquirrelContract/SquirrelDatabase/SquirrelDbContext.cs

@@ -0,0 +1,53 @@
+using Microsoft.EntityFrameworkCore;
+using SquirrelContract.Infastructure;
+using SquirrelDatabase.Models;
+
+namespace SquirrelDatabase;
+
+public class SquirrelDbContext(IConfigurationDatabase configurationDatabase) : DbContext
+{
+    private readonly IConfigurationDatabase? _configurationDatabase = configurationDatabase;
+
+    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+    {
+        optionsBuilder.UseNpgsql(_configurationDatabase?.ConnectionString, o => o.SetPostgresVersion(12, 2));
+        base.OnConfiguring(optionsBuilder);
+    }
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        base.OnModelCreating(modelBuilder);
+
+        modelBuilder.Entity<Client>().HasIndex(x => x.PhoneNumber).IsUnique();
+
+        modelBuilder.Entity<Cocktail>().HasIndex(x => x.CocktailName).IsUnique();
+
+        modelBuilder.Entity<Post>()
+            .HasIndex(e => new { e.PostName, e.IsActual })
+            .IsUnique()
+            .HasFilter($"\"{nameof(Post.IsActual)}\" = TRUE");
+
+        modelBuilder.Entity<Post>()
+            .HasIndex(e => new { e.PostId, e.IsActual })
+            .IsUnique()
+            .HasFilter($"\"{nameof(Post.IsActual)}\" = TRUE");
+
+        modelBuilder.Entity<SaleCocktail>().HasKey(x => new { x.SaleId, x.CocktailId });
+    }
+
+    public DbSet<Client> Clients { get; set; }
+
+    public DbSet<Post> Posts { get; set; }
+
+    public DbSet<Cocktail> Cocktails { get; set; }
+
+    public DbSet<CocktailHistory> CocktailHistories { get; set; }
+
+    public DbSet<Salary> Salaries { get; set; }
+
+    public DbSet<Sale> Sales { get; set; }
+
+    public DbSet<SaleCocktail> SaleCocktails { get; set; }
+
+    public DbSet<Employee> Employees { get; set; }
+}

SquirrelContract/SquirrelTests/BusinessLogicContractsTests/ClientBusinessLogicContractTests.cs

@@ -0,0 +1,351 @@
+using SquirrelBusinessLogic.Implementations;
+using SquirrelContract.DataModels;
+using Moq;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using Microsoft.Extensions.Logging;
+using SquirrelContract.BusinessLogicContracts;
+
+namespace SquirrelTests.BusinessLogicContractsTests;
+
+[TestFixture]
+internal class ClientBusinessLogicContractTests
+{
+    private IClientBusinessLogicContract _clientBusinessLogicContract;
+    private Mock<IClientStorageContract> _clientStorageContract;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUp()
+    {
+        _clientStorageContract = new Mock<IClientStorageContract>();
+        _clientBusinessLogicContract = new ClientBusinessLogicContract(_clientStorageContract.Object, new Mock<ILogger>().Object);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _clientStorageContract.Reset();
+    }
+
+    [Test]
+    public void GetAllCLients_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var listOriginal = new List<ClientDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), "fio 1", "+7-111-111-11-11", 0),
+            new(Guid.NewGuid().ToString(), "fio 2", "+7-555-444-33-23", 10),
+            new(Guid.NewGuid().ToString(), "fio 3", "+7-777-777-7777", 0),
+        };
+        _clientStorageContract.Setup(x => x.GetList()).Returns(listOriginal);
+        //Act
+        var list = _clientBusinessLogicContract.GetAllClients();
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+    }
+
+    [Test]
+    public void GetAllClients_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.GetList()).Returns([]);
+        //Act
+        var list = _clientBusinessLogicContract.GetAllClients();
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _clientStorageContract.Verify(x => x.GetList(), Times.Once);
+    }
+
+    [Test]
+    public void GetAllClients_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetAllClients(), Throws.TypeOf<NullListException>());
+        _clientStorageContract.Verify(x => x.GetList(), Times.Once);
+    }
+
+    [Test]
+    public void GetAllClients_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.GetList()).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetAllClients(), Throws.TypeOf<StorageException>());
+        _clientStorageContract.Verify(x => x.GetList(), Times.Once);
+    }
+
+    [Test]
+    public void GetClientByData_GetById_ReturnRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var record = new ClientDataModel(id, "fio", "+7-111-111-11-11", 0);
+        _clientStorageContract.Setup(x => x.GetElementById(id)).Returns(record);
+        //Act
+        var element = _clientBusinessLogicContract.GetClientByData(id);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.Id, Is.EqualTo(id));
+        _clientStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetClientByData_GetByFio_ReturnRecord_Test()
+    {
+        //Arrange
+        var fio = "fio";
+        var record = new ClientDataModel(Guid.NewGuid().ToString(), fio, "+7-111-111-11-11", 0);
+        _clientStorageContract.Setup(x => x.GetElementByFIO(fio)).Returns(record);
+        //Act
+        var element = _clientBusinessLogicContract.GetClientByData(fio);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.FIO, Is.EqualTo(fio));
+        _clientStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetClientByData_GetByPhoneNumber_ReturnRecord_Test()
+    {
+        //Arrange
+        var phoneNumber = "+7-111-111-11-11";
+        var record = new ClientDataModel(Guid.NewGuid().ToString(), "fio", phoneNumber, 0);
+        _clientStorageContract.Setup(x => x.GetElementByPhoneNumber(phoneNumber)).Returns(record);
+        //Act
+        var element = _clientBusinessLogicContract.GetClientByData(phoneNumber);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.PhoneNumber, Is.EqualTo(phoneNumber));
+        _clientStorageContract.Verify(x => x.GetElementByPhoneNumber(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetClientByData_EmptyData_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _clientStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _clientStorageContract.Verify(x => x.GetElementByPhoneNumber(It.IsAny<string>()), Times.Never);
+        _clientStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetClientByData_GetById_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _clientStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _clientStorageContract.Verify(x => x.GetElementByPhoneNumber(It.IsAny<string>()), Times.Never);
+        _clientStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetClientByData_GetByFio_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData("fio"), Throws.TypeOf<ElementNotFoundException>());
+        _clientStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _clientStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Once);
+        _clientStorageContract.Verify(x => x.GetElementByPhoneNumber(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetClientByData_GetByPhoneNumber_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData("+7-111-111-11-12"), Throws.TypeOf<ElementNotFoundException>());
+        _clientStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _clientStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Never);
+        _clientStorageContract.Verify(x => x.GetElementByPhoneNumber(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetClientByData_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.GetElementById(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        _clientStorageContract.Setup(x => x.GetElementByFIO(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        _clientStorageContract.Setup(x => x.GetElementByPhoneNumber(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData("fio"), Throws.TypeOf<StorageException>());
+        Assert.That(() => _clientBusinessLogicContract.GetClientByData("+7-111-111-11-12"), Throws.TypeOf<StorageException>());
+        _clientStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _clientStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Once);
+        _clientStorageContract.Verify(x => x.GetElementByPhoneNumber(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertClient_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new ClientDataModel(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 10);
+        _clientStorageContract.Setup(x => x.AddElement(It.IsAny<ClientDataModel>()))
+            .Callback((ClientDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.FIO == record.FIO &&
+                    x.PhoneNumber == record.PhoneNumber && x.DiscountSize == record.DiscountSize;
+            });
+        //Act
+        _clientBusinessLogicContract.InsertClient(record);
+        //Assert
+        _clientStorageContract.Verify(x => x.AddElement(It.IsAny<ClientDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void InsertClient_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.AddElement(It.IsAny<ClientDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.InsertClient(new(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 0)), Throws.TypeOf<ElementExistsException>());
+        _clientStorageContract.Verify(x => x.AddElement(It.IsAny<ClientDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertClient_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.InsertClient(null), Throws.TypeOf<ArgumentNullException>());
+        _clientStorageContract.Verify(x => x.AddElement(It.IsAny<ClientDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertClient_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.InsertClient(new ClientDataModel("id", "fio", "+7-111-111-11-11", 10)), Throws.TypeOf<ValidationException>());
+        _clientStorageContract.Verify(x => x.AddElement(It.IsAny<ClientDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertClient_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.AddElement(It.IsAny<ClientDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.InsertClient(new(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 0)), Throws.TypeOf<StorageException>());
+        _clientStorageContract.Verify(x => x.AddElement(It.IsAny<ClientDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateClient_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new ClientDataModel(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 0);
+        _clientStorageContract.Setup(x => x.UpdElement(It.IsAny<ClientDataModel>()))
+            .Callback((ClientDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.FIO == record.FIO &&
+                    x.PhoneNumber == record.PhoneNumber && x.DiscountSize == record.DiscountSize;
+            });
+        //Act
+        _clientBusinessLogicContract.UpdateClient(record);
+        //Assert
+        _clientStorageContract.Verify(x => x.UpdElement(It.IsAny<ClientDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void UpdateClient_RecordWithIncorrectData_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.UpdElement(It.IsAny<ClientDataModel>())).Throws(new ElementNotFoundException(""));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.UpdateClient(new(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 0)), Throws.TypeOf<ElementNotFoundException>());
+        _clientStorageContract.Verify(x => x.UpdElement(It.IsAny<ClientDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateClient_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.UpdElement(It.IsAny<ClientDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.UpdateClient(new(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 0)), Throws.TypeOf<ElementExistsException>());
+        _clientStorageContract.Verify(x => x.UpdElement(It.IsAny<ClientDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateClient_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.UpdateClient(null), Throws.TypeOf<ArgumentNullException>());
+        _clientStorageContract.Verify(x => x.UpdElement(It.IsAny<ClientDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdateClient_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.UpdateClient(new ClientDataModel("id", "fio", "+7-111-111-11-11", 10)), Throws.TypeOf<ValidationException>());
+        _clientStorageContract.Verify(x => x.UpdElement(It.IsAny<ClientDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdateClient_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.UpdElement(It.IsAny<ClientDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.UpdateClient(new(Guid.NewGuid().ToString(), "fio", "+7-111-111-11-11", 0)), Throws.TypeOf<StorageException>());
+        _clientStorageContract.Verify(x => x.UpdElement(It.IsAny<ClientDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void DeleteClient_CorrectRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var flag = false;
+        _clientStorageContract.Setup(x => x.DelElement(It.Is((string x) => x == id))).Callback(() => { flag = true; });
+        //Act
+        _clientBusinessLogicContract.DeleteClient(id);
+        //Assert
+        _clientStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void DeleteClient_RecordWithIncorrectId_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new ElementNotFoundException(""));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.DeleteClient(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _clientStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void DeleteClient_IdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.DeleteClient(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _clientBusinessLogicContract.DeleteClient(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _clientStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeleteClient_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.DeleteClient("id"), Throws.TypeOf<ValidationException>());
+        _clientStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeleteClient_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _clientStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _clientBusinessLogicContract.DeleteClient(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _clientStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+}

SquirrelContract/SquirrelTests/BusinessLogicContractsTests/CocktailBusinessLogicContractTests.cs

@@ -0,0 +1,390 @@
+using Microsoft.Extensions.Logging;
+using Moq;
+using SquirrelBusinessLogic.Implementations;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+using System.Xml.Linq;
+using static NUnit.Framework.Internal.OSPlatform;
+
+namespace SquirrelTests.BusinessLogicContractsTests;
+
+[TestFixture]
+internal class CocktailBusinessLogicContractTests
+{
+    private CocktailBusinessLogicContract _cocktailBusinessLogicContract;
+    private Mock<ICocktailStorageContract> _cocktailStorageContract;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUp()
+    {
+        _cocktailStorageContract = new Mock<ICocktailStorageContract>();
+        _cocktailBusinessLogicContract = new CocktailBusinessLogicContract(_cocktailStorageContract.Object, new Mock<ILogger>().Object);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _cocktailStorageContract.Reset();
+    }
+
+    [Test]
+    public void GetAllCocktails_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var listOriginal = new List<CocktailDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), "name 1", 15.5, AlcoholType.Wine),
+            new(Guid.NewGuid().ToString(), "name 2", 15.5, AlcoholType.Wine),
+            new(Guid.NewGuid().ToString(), "name 3", 15.5, AlcoholType.Wine),
+        };
+        _cocktailStorageContract.Setup(x => x.GetList()).Returns(listOriginal);
+        //Act
+        var list = _cocktailBusinessLogicContract.GetAllCocktails();
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+    }
+
+    [Test]
+    public void GetAllCocktails_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.GetList()).Returns([]);
+        //Act
+        var list = _cocktailBusinessLogicContract.GetAllCocktails();
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _cocktailStorageContract.Verify(x => x.GetList(), Times.Once);
+    }
+
+    [Test]
+    public void GetAllCocktails_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetAllCocktails(), Throws.TypeOf<NullListException>());
+        _cocktailStorageContract.Verify(x => x.GetList(), Times.Once);
+    }
+
+    [Test]
+    public void GetAllCocktails_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.GetList()).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetAllCocktails(), Throws.TypeOf<StorageException>());
+        _cocktailStorageContract.Verify(x => x.GetList(), Times.Once);
+    }    
+
+    [Test]
+    public void GetCocktailHistoryByCocktail_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var cocktailId = Guid.NewGuid().ToString();
+        var listOriginal = new List<CocktailHistoryDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), 10),
+            new(Guid.NewGuid().ToString(), 15),
+            new(Guid.NewGuid().ToString(), 10),
+        };
+        _cocktailStorageContract.Setup(x => x.GetHistoryByCocktailId(It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail(cocktailId);
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _cocktailStorageContract.Verify(x => x.GetHistoryByCocktailId(cocktailId), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailHistoryByCocktail_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.GetHistoryByCocktailId(It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail(Guid.NewGuid().ToString());
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _cocktailStorageContract.Verify(x => x.GetHistoryByCocktailId(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailHistoryByCocktail_CocktailIdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _cocktailStorageContract.Verify(x => x.GetHistoryByCocktailId(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetCocktailHistoryByCocktail_CocktailIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail("cocktailId"), Throws.TypeOf<ValidationException>());
+        _cocktailStorageContract.Verify(x => x.GetHistoryByCocktailId(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetCocktailHistoryByCocktail_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail(Guid.NewGuid().ToString()), Throws.TypeOf<NullListException>());
+        _cocktailStorageContract.Verify(x => x.GetHistoryByCocktailId(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailHistoryByCocktail_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.GetHistoryByCocktailId(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailHistoryByCocktail(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _cocktailStorageContract.Verify(x => x.GetHistoryByCocktailId(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailByData_GetById_ReturnRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var record = new CocktailDataModel(id, "name", 10, AlcoholType.Wine);
+        _cocktailStorageContract.Setup(x => x.GetElementById(id)).Returns(record);
+        //Act
+        var element = _cocktailBusinessLogicContract.GetCocktailByData(id);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.Id, Is.EqualTo(id));
+        _cocktailStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailByData_GetByName_ReturnRecord_Test()
+    {
+        //Arrange
+        var name = "name";
+        var record = new CocktailDataModel(Guid.NewGuid().ToString(), name, 10, AlcoholType.Wine);
+        _cocktailStorageContract.Setup(x => x.GetElementByName(name)).Returns(record);
+        //Act
+        var element = _cocktailBusinessLogicContract.GetCocktailByData(name);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.CocktailName, Is.EqualTo(name));
+        _cocktailStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailByData_EmptyData_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailByData(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailByData(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _cocktailStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Never);
+        _cocktailStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetCocktailByData_GetById_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailByData(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _cocktailStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailByData_GetByName_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailByData("name"), Throws.TypeOf<ElementNotFoundException>());
+        _cocktailStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetCocktailByData_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.GetElementById(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        _cocktailStorageContract.Setup(x => x.GetElementByName(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailByData(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        Assert.That(() => _cocktailBusinessLogicContract.GetCocktailByData("name"), Throws.TypeOf<StorageException>());
+        _cocktailStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _cocktailStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertCocktail_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new CocktailDataModel(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine);
+        _cocktailStorageContract.Setup(x => x.AddElement(It.IsAny<CocktailDataModel>()))
+            .Callback((CocktailDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.CocktailName == record.CocktailName &&
+                    x.Price == record.Price && x.BaseAlcohol == record.BaseAlcohol;
+            });
+        //Act
+        _cocktailBusinessLogicContract.InsertCocktail(record);
+        //Assert
+        _cocktailStorageContract.Verify(x => x.AddElement(It.IsAny<CocktailDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void InsertCocktail_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.AddElement(It.IsAny<CocktailDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.InsertCocktail(new(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine)), Throws.TypeOf<ElementExistsException>());
+        _cocktailStorageContract.Verify(x => x.AddElement(It.IsAny<CocktailDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertCocktail_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.InsertCocktail(null), Throws.TypeOf<ArgumentNullException>());
+        _cocktailStorageContract.Verify(x => x.AddElement(It.IsAny<CocktailDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertCocktail_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.InsertCocktail(new CocktailDataModel("id", "name", 10, AlcoholType.Wine)), Throws.TypeOf<ValidationException>());
+        _cocktailStorageContract.Verify(x => x.AddElement(It.IsAny<CocktailDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertCocktail_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.AddElement(It.IsAny<CocktailDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.InsertCocktail(new(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine)), Throws.TypeOf<StorageException>());
+        _cocktailStorageContract.Verify(x => x.AddElement(It.IsAny<CocktailDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateCocktail_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new CocktailDataModel(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine);
+        _cocktailStorageContract.Setup(x => x.UpdElement(It.IsAny<CocktailDataModel>()))
+            .Callback((CocktailDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.CocktailName == record.CocktailName &&
+                    x.Price == record.Price && x.BaseAlcohol == record.BaseAlcohol;
+            });
+        //Act
+        _cocktailBusinessLogicContract.UpdateCocktail(record);
+        //Assert
+        _cocktailStorageContract.Verify(x => x.UpdElement(It.IsAny<CocktailDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void UpdateCocktail_RecordWithIncorrectData_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.UpdElement(It.IsAny<CocktailDataModel>())).Throws(new ElementNotFoundException(""));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.UpdateCocktail(new(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine)), Throws.TypeOf<ElementNotFoundException>());
+        _cocktailStorageContract.Verify(x => x.UpdElement(It.IsAny<CocktailDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateCocktail_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.UpdElement(It.IsAny<CocktailDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.UpdateCocktail(new(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine)), Throws.TypeOf<ElementExistsException>());
+        _cocktailStorageContract.Verify(x => x.UpdElement(It.IsAny<CocktailDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateCocktail_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.UpdateCocktail(null), Throws.TypeOf<ArgumentNullException>());
+        _cocktailStorageContract.Verify(x => x.UpdElement(It.IsAny<CocktailDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdateCocktail_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.UpdateCocktail(new CocktailDataModel("id", "name", 10, AlcoholType.Wine)), Throws.TypeOf<ValidationException>());
+        _cocktailStorageContract.Verify(x => x.UpdElement(It.IsAny<CocktailDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdateCocktail_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.UpdElement(It.IsAny<CocktailDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.UpdateCocktail(new(Guid.NewGuid().ToString(), "name", 10, AlcoholType.Wine)), Throws.TypeOf<StorageException>());
+        _cocktailStorageContract.Verify(x => x.UpdElement(It.IsAny<CocktailDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void DeleteCocktail_CorrectRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var flag = false;
+        _cocktailStorageContract.Setup(x => x.DelElement(It.Is((string x) => x == id))).Callback(() => { flag = true; });
+        //Act
+        _cocktailBusinessLogicContract.DeleteCocktail(id);
+        //Assert
+        _cocktailStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void DeleteCocktail_RecordWithIncorrectId_ThrowException_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        _cocktailStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new ElementNotFoundException(id));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.DeleteCocktail(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _cocktailStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void DeleteCocktail_IdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.DeleteCocktail(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _cocktailBusinessLogicContract.DeleteCocktail(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _cocktailStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeleteCocktail_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.DeleteCocktail("id"), Throws.TypeOf<ValidationException>());
+        _cocktailStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeleteCocktail_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _cocktailStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _cocktailBusinessLogicContract.DeleteCocktail(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _cocktailStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+}

SquirrelContract/SquirrelTests/BusinessLogicContractsTests/EmployeeBusinessLogicContractTests.cs

@@ -0,0 +1,582 @@
+using Microsoft.Extensions.Logging;
+using Moq;
+using SquirrelBusinessLogic.Implementations;
+using SquirrelContract.BusinessLogicContracts;
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+
+namespace SquirrelTests.BusinessLogicContractsTests;
+
+[TestFixture]
+internal class EmployeeBusinessLogicContractTests
+{
+    private EmployeeBusinessLogicContract _employeeBusinessLogicContract;
+    private Mock<IEmployeeStorageContract> _employeeStorageContract;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUp()
+    {
+        _employeeStorageContract = new Mock<IEmployeeStorageContract>();
+        _employeeBusinessLogicContract = new EmployeeBusinessLogicContract(_employeeStorageContract.Object, new Mock<ILogger>().Object);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _employeeStorageContract.Reset();
+    }
+
+    [Test]
+    public void GetAllEmployees_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var listOriginal = new List<EmployeeDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), "fio 1", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+            new(Guid.NewGuid().ToString(), "fio 2", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, true),
+            new(Guid.NewGuid().ToString(), "fio 3", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+        };
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns(listOriginal);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployees(true);
+        var list = _employeeBusinessLogicContract.GetAllEmployees(false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Is.EquivalentTo(listOriginal));
+            Assert.That(list, Is.EquivalentTo(listOriginal));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(true, null, null, null, null, null), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetList(false, null, null, null, null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployees_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns([]);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployees(true);
+        var list = _employeeBusinessLogicContract.GetAllEmployees(false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Has.Count.EqualTo(0));
+            Assert.That(list, Has.Count.EqualTo(0));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), null, null, null, null, null), Times.Exactly(2));
+    }
+
+    [Test]
+    public void GetAllEmployees_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployees(It.IsAny<bool>()), Throws.TypeOf<NullListException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployees_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployees(It.IsAny<bool>()), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), null, null, null, null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByPost_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var postId = Guid.NewGuid().ToString();
+        var listOriginal = new List<EmployeeDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), "fio 1", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+            new(Guid.NewGuid().ToString(), "fio 2", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, true),
+            new(Guid.NewGuid().ToString(), "fio 3", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+        };
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns(listOriginal);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployeesByPost(postId, true);
+        var list = _employeeBusinessLogicContract.GetAllEmployeesByPost(postId, false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Is.EquivalentTo(listOriginal));
+            Assert.That(list, Is.EquivalentTo(listOriginal));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(true, postId, null, null, null, null), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetList(false, postId, null, null, null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByPost_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns([]);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployeesByPost(Guid.NewGuid().ToString(), true);
+        var list = _employeeBusinessLogicContract.GetAllEmployeesByPost(Guid.NewGuid().ToString(), false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Has.Count.EqualTo(0));
+            Assert.That(list, Has.Count.EqualTo(0));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Exactly(2));
+    }
+
+    [Test]
+    public void GetAllEmployeesByPost_PostIdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByPost(null, It.IsAny<bool>()), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByPost(string.Empty, It.IsAny<bool>()), Throws.TypeOf<ArgumentNullException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllEmployeesByPost_PostIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByPost("postId", It.IsAny<bool>()), Throws.TypeOf<ValidationException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllEmployeesByPost_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByPost(Guid.NewGuid().ToString(), It.IsAny<bool>()), Throws.TypeOf<NullListException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByPost_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByPost(Guid.NewGuid().ToString(), It.IsAny<bool>()), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByBirthDate_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        var listOriginal = new List<EmployeeDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), "fio 1", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+            new(Guid.NewGuid().ToString(), "fio 2", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, true),
+            new(Guid.NewGuid().ToString(), "fio 3", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+        };
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns(listOriginal);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(date, date.AddDays(1), true);
+        var list = _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(date, date.AddDays(1), false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Is.EquivalentTo(listOriginal));
+            Assert.That(list, Is.EquivalentTo(listOriginal));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(true, null, date, date.AddDays(1), null, null), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetList(false, null, date, date.AddDays(1), null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByBirthDate_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns([]);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), true);
+        var list = _employeeBusinessLogicContract.GetAllEmployees(false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Has.Count.EqualTo(0));
+            Assert.That(list, Has.Count.EqualTo(0));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(true, null, It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), null, null), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetList(false, null, It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByBirthDate_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(date, date, It.IsAny<bool>()), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(date, date.AddSeconds(-1), It.IsAny<bool>()), Throws.TypeOf<IncorrectDatesException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllEmployeesByBirthDate_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), It.IsAny<bool>()), Throws.TypeOf<NullListException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByBirthDate_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByBirthDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), It.IsAny<bool>()), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByEmploymentDate_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        var listOriginal = new List<EmployeeDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), "fio 1", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+            new(Guid.NewGuid().ToString(), "fio 2", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, true),
+            new(Guid.NewGuid().ToString(), "fio 3", "gg@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false),
+        };
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns(listOriginal);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(date, date.AddDays(1), true);
+        var list = _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(date, date.AddDays(1), false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Is.EquivalentTo(listOriginal));
+            Assert.That(list, Is.EquivalentTo(listOriginal));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(true, null, null, null, date, date.AddDays(1)), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetList(false, null, null, null, date, date.AddDays(1)), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByEmploymentDate_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Returns([]);
+        //Act
+        var listOnlyActive = _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), true);
+        var list = _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(list, Is.Not.Null);
+            Assert.That(listOnlyActive, Has.Count.EqualTo(0));
+            Assert.That(list, Has.Count.EqualTo(0));
+        });
+        _employeeStorageContract.Verify(x => x.GetList(true, null, null, null, It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetList(false, null, null, null, It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByEmploymentDate_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(date, date, It.IsAny<bool>()), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(date, date.AddSeconds(-1), It.IsAny<bool>()), Throws.TypeOf<IncorrectDatesException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllEmployeesByEmploymentDate_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), It.IsAny<bool>()), Throws.TypeOf<NullListException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllEmployeesByEmploymentDate_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetAllEmployeesByEmploymentDate(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), It.IsAny<bool>()), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()), Times.Once);
+    }
+
+    [Test]
+    public void GetEmployeeByData_GetById_ReturnRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var record = new EmployeeDataModel(id, "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false);
+        _employeeStorageContract.Setup(x => x.GetElementById(id)).Returns(record);
+        //Act
+        var element = _employeeBusinessLogicContract.GetEmployeeByData(id);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.Id, Is.EqualTo(id));
+        _employeeStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetEmployeeByData_GetByFio_ReturnRecord_Test()
+    {
+        //Arrange
+        var fio = "fio";
+        var record = new EmployeeDataModel(Guid.NewGuid().ToString(), fio, "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false);
+        _employeeStorageContract.Setup(x => x.GetElementByFIO(fio)).Returns(record);
+        //Act
+        var element = _employeeBusinessLogicContract.GetEmployeeByData(fio);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.FIO, Is.EqualTo(fio));
+        _employeeStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetEmployeeByData_GetByEmail_ReturnRecord_Test()
+    {
+        //Arrange
+        var email = "123@gmail.com";
+        var record = new EmployeeDataModel(Guid.NewGuid().ToString(), "fio", email, Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false);
+        _employeeStorageContract.Setup(x => x.GetElementByEmail(email)).Returns(record);
+        //Act
+        var element = _employeeBusinessLogicContract.GetEmployeeByData(email);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.Email, Is.EqualTo(email));
+        _employeeStorageContract.Verify(x => x.GetElementByEmail(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetEmployeeByData_EmptyData_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _employeeStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _employeeStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetEmployeeByData_GetById_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _employeeStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetEmployeeByData_GetByFio_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData("fio"), Throws.TypeOf<ElementNotFoundException>());
+        _employeeStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _employeeStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetEmployeeByData_GetByEmail_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData("123@gmail.com"), Throws.TypeOf<ElementNotFoundException>());
+        _employeeStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _employeeStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetEmployeeByData_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.GetElementById(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        _employeeStorageContract.Setup(x => x.GetElementByFIO(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        Assert.That(() => _employeeBusinessLogicContract.GetEmployeeByData("fio"), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _employeeStorageContract.Verify(x => x.GetElementByFIO(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertEmployee_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new EmployeeDataModel(Guid.NewGuid().ToString(), "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false);
+        _employeeStorageContract.Setup(x => x.AddElement(It.IsAny<EmployeeDataModel>()))
+            .Callback((EmployeeDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.FIO == record.FIO && x.PostId == record.PostId && x.BirthDate == record.BirthDate &&
+                    x.EmploymentDate == record.EmploymentDate && x.IsDeleted == record.IsDeleted;
+            });
+        //Act
+        _employeeBusinessLogicContract.InsertEmployee(record);
+        //Assert
+        _employeeStorageContract.Verify(x => x.AddElement(It.IsAny<EmployeeDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void InsertEmployee_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.AddElement(It.IsAny<EmployeeDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.InsertEmployee(new(Guid.NewGuid().ToString(), "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false)), Throws.TypeOf<ElementExistsException>());
+        _employeeStorageContract.Verify(x => x.AddElement(It.IsAny<EmployeeDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertEmployee_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.InsertEmployee(null), Throws.TypeOf<ArgumentNullException>());
+        _employeeStorageContract.Verify(x => x.AddElement(It.IsAny<EmployeeDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertEmployee_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.InsertEmployee(new EmployeeDataModel("id", "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false)), Throws.TypeOf<ValidationException>());
+        _employeeStorageContract.Verify(x => x.AddElement(It.IsAny<EmployeeDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertEmployee_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.AddElement(It.IsAny<EmployeeDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.InsertEmployee(new(Guid.NewGuid().ToString(), "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false)), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.AddElement(It.IsAny<EmployeeDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateEmployee_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new EmployeeDataModel(Guid.NewGuid().ToString(), "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false);
+        _employeeStorageContract.Setup(x => x.UpdElement(It.IsAny<EmployeeDataModel>()))
+            .Callback((EmployeeDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.FIO == record.FIO && x.PostId == record.PostId && x.BirthDate == record.BirthDate &&
+                    x.EmploymentDate == record.EmploymentDate && x.IsDeleted == record.IsDeleted;
+            });
+        //Act
+        _employeeBusinessLogicContract.UpdateEmployee(record);
+        //Assert
+        _employeeStorageContract.Verify(x => x.UpdElement(It.IsAny<EmployeeDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void UpdateEmployee_RecordWithIncorrectData_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.UpdElement(It.IsAny<EmployeeDataModel>())).Throws(new ElementNotFoundException(""));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.UpdateEmployee(new(Guid.NewGuid().ToString(), "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false)), Throws.TypeOf<ElementNotFoundException>());
+        _employeeStorageContract.Verify(x => x.UpdElement(It.IsAny<EmployeeDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdateEmployee_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.UpdateEmployee(null), Throws.TypeOf<ArgumentNullException>());
+        _employeeStorageContract.Verify(x => x.UpdElement(It.IsAny<EmployeeDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdateEmployee_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.UpdateEmployee(new EmployeeDataModel("id", "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false)), Throws.TypeOf<ValidationException>());
+        _employeeStorageContract.Verify(x => x.UpdElement(It.IsAny<EmployeeDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdateEmployee_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.UpdElement(It.IsAny<EmployeeDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.UpdateEmployee(new(Guid.NewGuid().ToString(), "fio", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18).AddDays(-1), DateTime.Now, false)), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.UpdElement(It.IsAny<EmployeeDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void DeleteEmployee_CorrectRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var flag = false;
+        _employeeStorageContract.Setup(x => x.DelElement(It.Is((string x) => x == id))).Callback(() => { flag = true; });
+        //Act
+        _employeeBusinessLogicContract.DeleteEmployee(id);
+        //Assert
+        _employeeStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void DeleteEmployee_RecordWithIncorrectId_ThrowException_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        _employeeStorageContract.Setup(x => x.DelElement(It.Is((string x) => x != id))).Throws(new ElementNotFoundException(id));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.DeleteEmployee(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _employeeStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void DeleteEmployee_IdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.DeleteEmployee(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _employeeBusinessLogicContract.DeleteEmployee(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _employeeStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeleteEmployee_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.DeleteEmployee("id"), Throws.TypeOf<ValidationException>());
+        _employeeStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeleteEmployee_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _employeeStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _employeeBusinessLogicContract.DeleteEmployee(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _employeeStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+}

SquirrelContract/SquirrelTests/BusinessLogicContractsTests/PostBusinessLogicContractTests.cs

@@ -0,0 +1,454 @@
+using Microsoft.Extensions.Logging;
+using Moq;
+using SquirrelBusinessLogic.Implementations;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+
+namespace SquirrelTests.BusinessLogicContractsTests;
+
+[TestFixture]
+internal class PostBusinessLogicContractTests
+{
+    private PostBusinessLogicContract _postBusinessLogicContract;
+    private Mock<IPostStorageContract> _postStorageContract;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUp()
+    {
+        _postStorageContract = new Mock<IPostStorageContract>();
+        _postBusinessLogicContract = new PostBusinessLogicContract(_postStorageContract.Object, new Mock<ILogger>().Object);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _postStorageContract.Reset();
+    }
+
+    [Test]
+    public void GetAllPosts_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var listOriginal = new List<PostDataModel>()
+        {
+            new(Guid.NewGuid().ToString(),"name 1", PostType.Manager, 10, true, DateTime.UtcNow),
+            new(Guid.NewGuid().ToString(), "name 2", PostType.Manager, 10, false, DateTime.UtcNow),
+            new(Guid.NewGuid().ToString(), "name 3", PostType.Manager, 10, true, DateTime.UtcNow),
+        };
+        _postStorageContract.Setup(x => x.GetList(It.IsAny<bool>())).Returns(listOriginal);
+        //Act
+        var listOnlyActive = _postBusinessLogicContract.GetAllPosts(true);
+        var listAll = _postBusinessLogicContract.GetAllPosts(false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(listAll, Is.Not.Null);
+            Assert.That(listOnlyActive, Is.EquivalentTo(listOriginal));
+            Assert.That(listAll, Is.EquivalentTo(listOriginal));
+        });
+        _postStorageContract.Verify(x => x.GetList(true), Times.Once);
+        _postStorageContract.Verify(x => x.GetList(false), Times.Once);
+    }
+
+    [Test]
+    public void GetAllPosts_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.GetList(It.IsAny<bool>())).Returns([]);
+        //Act
+        var listOnlyActive = _postBusinessLogicContract.GetAllPosts(true);
+        var listAll = _postBusinessLogicContract.GetAllPosts(false);
+        //Assert
+        Assert.Multiple(() =>
+        {
+            Assert.That(listOnlyActive, Is.Not.Null);
+            Assert.That(listAll, Is.Not.Null);
+            Assert.That(listOnlyActive, Has.Count.EqualTo(0));
+            Assert.That(listAll, Has.Count.EqualTo(0));
+        });
+        _postStorageContract.Verify(x => x.GetList(It.IsAny<bool>()), Times.Exactly(2));
+    }
+
+    [Test]
+    public void GetAllPosts_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetAllPosts(It.IsAny<bool>()), Throws.TypeOf<NullListException>());
+        _postStorageContract.Verify(x => x.GetList(It.IsAny<bool>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllPosts_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.GetList(It.IsAny<bool>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetAllPosts(It.IsAny<bool>()), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.GetList(It.IsAny<bool>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllDataOfPost_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var postId = Guid.NewGuid().ToString();
+        var listOriginal = new List<PostDataModel>()
+        {
+            new(postId, "name 1", PostType.Manager, 10, true, DateTime.UtcNow),
+            new(postId, "name 2", PostType.Manager, 10, false, DateTime.UtcNow)
+        };
+        _postStorageContract.Setup(x => x.GetPostWithHistory(It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _postBusinessLogicContract.GetAllDataOfPost(postId);
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+        _postStorageContract.Verify(x => x.GetPostWithHistory(postId), Times.Once);
+    }
+
+    [Test]
+    public void GetAllDataOfPost_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.GetPostWithHistory(It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _postBusinessLogicContract.GetAllDataOfPost(Guid.NewGuid().ToString());
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _postStorageContract.Verify(x => x.GetPostWithHistory(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllDataOfPost_PostIdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetAllDataOfPost(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _postBusinessLogicContract.GetAllDataOfPost(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _postStorageContract.Verify(x => x.GetPostWithHistory(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllDataOfPost_PostIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetAllDataOfPost("id"), Throws.TypeOf<ValidationException>());
+        _postStorageContract.Verify(x => x.GetPostWithHistory(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllDataOfPost_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetAllDataOfPost(Guid.NewGuid().ToString()), Throws.TypeOf<NullListException>());
+        _postStorageContract.Verify(x => x.GetPostWithHistory(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllDataOfPost_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.GetPostWithHistory(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetAllDataOfPost(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.GetPostWithHistory(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetPostByData_GetById_ReturnRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var record = new PostDataModel(id, "name", PostType.Manager, 10, true, DateTime.UtcNow);
+        _postStorageContract.Setup(x => x.GetElementById(id)).Returns(record);
+        //Act
+        var element = _postBusinessLogicContract.GetPostByData(id);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.Id, Is.EqualTo(id));
+        _postStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetPostByData_GetByName_ReturnRecord_Test()
+    {
+        //Arrange
+        var postName = "name";
+        var record = new PostDataModel(Guid.NewGuid().ToString(), postName, PostType.Manager, 10, true, DateTime.UtcNow);
+        _postStorageContract.Setup(x => x.GetElementByName(postName)).Returns(record);
+        //Act
+        var element = _postBusinessLogicContract.GetPostByData(postName);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.PostName, Is.EqualTo(postName));
+        _postStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetPostByData_EmptyData_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetPostByData(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _postBusinessLogicContract.GetPostByData(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _postStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _postStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetPostByData_GetById_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetPostByData(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _postStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _postStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetPostByData_GetByName_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetPostByData("name"), Throws.TypeOf<ElementNotFoundException>());
+        _postStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+        _postStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetPostByData_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        _postStorageContract.Setup(x => x.GetElementByName(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.GetPostByData(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        Assert.That(() => _postBusinessLogicContract.GetPostByData("name"), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+        _postStorageContract.Verify(x => x.GetElementByName(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertPost_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Bartender, 10, true, DateTime.UtcNow.AddDays(-1));
+        _postStorageContract.Setup(x => x.AddElement(It.IsAny<PostDataModel>()))
+            .Callback((PostDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.PostName == record.PostName && x.PostType == record.PostType && x.Salary == record.Salary &&
+                    x.ChangeDate == record.ChangeDate;
+            });
+        //Act
+        _postBusinessLogicContract.InsertPost(record);
+        //Assert
+        _postStorageContract.Verify(x => x.AddElement(It.IsAny<PostDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void InsertPost_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.AddElement(It.IsAny<PostDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.InsertPost(new(Guid.NewGuid().ToString(), "name", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<ElementExistsException>());
+        _postStorageContract.Verify(x => x.AddElement(It.IsAny<PostDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertPost_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.InsertPost(null), Throws.TypeOf<ArgumentNullException>());
+        _postStorageContract.Verify(x => x.AddElement(It.IsAny<PostDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertPost_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.InsertPost(new PostDataModel("id", "name", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<ValidationException>());
+        _postStorageContract.Verify(x => x.AddElement(It.IsAny<PostDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertPost_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.AddElement(It.IsAny<PostDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.InsertPost(new(Guid.NewGuid().ToString(), "name", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.AddElement(It.IsAny<PostDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdatePost_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Bartender, 10, true, DateTime.UtcNow.AddDays(-1));
+        _postStorageContract.Setup(x => x.UpdElement(It.IsAny<PostDataModel>()))
+            .Callback((PostDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.PostName == record.PostName && x.PostType == record.PostType && x.Salary == record.Salary &&
+                    x.ChangeDate == record.ChangeDate;
+            });
+        //Act
+        _postBusinessLogicContract.UpdatePost(record);
+        //Assert
+        _postStorageContract.Verify(x => x.UpdElement(It.IsAny<PostDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void UpdatePost_RecordWithIncorrectData_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.UpdElement(It.IsAny<PostDataModel>())).Throws(new ElementNotFoundException(""));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.UpdatePost(new(Guid.NewGuid().ToString(), "name", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<ElementNotFoundException>());
+        _postStorageContract.Verify(x => x.UpdElement(It.IsAny<PostDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdatePost_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.UpdElement(It.IsAny<PostDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.UpdatePost(new(Guid.NewGuid().ToString(), "anme", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<ElementExistsException>());
+        _postStorageContract.Verify(x => x.UpdElement(It.IsAny<PostDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void UpdatePost_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.UpdatePost(null), Throws.TypeOf<ArgumentNullException>());
+        _postStorageContract.Verify(x => x.UpdElement(It.IsAny<PostDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdatePost_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.UpdatePost(new PostDataModel("id", "name", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<ValidationException>());
+        _postStorageContract.Verify(x => x.UpdElement(It.IsAny<PostDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void UpdatePost_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.UpdElement(It.IsAny<PostDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.UpdatePost(new(Guid.NewGuid().ToString(), "name", PostType.Bartender, 10, true, DateTime.UtcNow)), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.UpdElement(It.IsAny<PostDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void DeletePost_CorrectRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var flag = false;
+        _postStorageContract.Setup(x => x.DelElement(It.Is((string x) => x == id))).Callback(() => { flag = true; });
+        //Act
+        _postBusinessLogicContract.DeletePost(id);
+        //Assert
+        _postStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void DeletePost_RecordWithIncorrectId_ThrowException_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        _postStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new ElementNotFoundException(id));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.DeletePost(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _postStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void DeletePost_IdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.DeletePost(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _postBusinessLogicContract.DeletePost(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _postStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeletePost_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.DeletePost("id"), Throws.TypeOf<ValidationException>());
+        _postStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void DeletePost_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.DeletePost(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void RestorePost_CorrectRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var flag = false;
+        _postStorageContract.Setup(x => x.ResElement(It.Is((string x) => x == id))).Callback(() => { flag = true; });
+        //Act
+        _postBusinessLogicContract.RestorePost(id);
+        //Assert
+        _postStorageContract.Verify(x => x.ResElement(It.IsAny<string>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void RestorePost_RecordWithIncorrectId_ThrowException_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        _postStorageContract.Setup(x => x.ResElement(It.IsAny<string>())).Throws(new ElementNotFoundException(id));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.RestorePost(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _postStorageContract.Verify(x => x.ResElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void RestorePost_IdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.RestorePost(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _postBusinessLogicContract.RestorePost(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _postStorageContract.Verify(x => x.ResElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void RestorePost_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.RestorePost("id"), Throws.TypeOf<ValidationException>());
+        _postStorageContract.Verify(x => x.ResElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void RestorePost_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _postStorageContract.Setup(x => x.ResElement(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _postBusinessLogicContract.RestorePost(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _postStorageContract.Verify(x => x.ResElement(It.IsAny<string>()), Times.Once);
+    }
+}

SquirrelContract/SquirrelTests/BusinessLogicContractsTests/SalaryBusinessLogicContractTests.cs

@@ -0,0 +1,347 @@
+using BarBelochkaContract.DataModels;
+using Microsoft.Extensions.Logging;
+using Moq;
+using SquirrelBusinessLogic.Implementations;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+
+namespace SquirrelTests.BusinessLogicContractsTests;
+
+[TestFixture]
+internal class SalaryBusinessLogicContractTests
+{
+    private SalaryBusinessLogicContract _salaryBusinessLogicContract;
+    private Mock<ISalaryStorageContract> _salaryStorageContract;
+    private Mock<ISaleStorageContract> _saleStorageContract;
+    private Mock<IPostStorageContract> _postStorageContract;
+    private Mock<IEmployeeStorageContract> _employeeStorageContract;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUp()
+    {
+        _salaryStorageContract = new Mock<ISalaryStorageContract>();
+        _saleStorageContract = new Mock<ISaleStorageContract>();
+        _postStorageContract = new Mock<IPostStorageContract>();
+        _employeeStorageContract = new Mock<IEmployeeStorageContract>();
+        _salaryBusinessLogicContract = new SalaryBusinessLogicContract(_salaryStorageContract.Object,
+            _saleStorageContract.Object, _postStorageContract.Object, _employeeStorageContract.Object, new Mock<ILogger>().Object);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _salaryStorageContract.Reset();
+        _saleStorageContract.Reset();
+        _postStorageContract.Reset();
+        _employeeStorageContract.Reset();
+    }
+
+    [Test]
+    public void GetAllSalaries_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var startDate = DateTime.UtcNow;
+        var endDate = DateTime.UtcNow.AddDays(1);
+        var listOriginal = new List<SalaryDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), DateTime.UtcNow, 10),
+            new(Guid.NewGuid().ToString(), DateTime.UtcNow.AddDays(1), 14),
+            new(Guid.NewGuid().ToString(), DateTime.UtcNow.AddDays(-1), 30),
+        };
+        _salaryStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _salaryBusinessLogicContract.GetAllSalariesByPeriod(startDate, endDate);
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _salaryStorageContract.Verify(x => x.GetList(startDate, endDate, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalaries_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _salaryStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _salaryBusinessLogicContract.GetAllSalariesByPeriod(DateTime.UtcNow, DateTime.UtcNow.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalaries_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var dateTime = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriod(dateTime, dateTime), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriod(dateTime, dateTime.AddSeconds(-1)), Throws.TypeOf<IncorrectDatesException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalaries_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriod(DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<NullListException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalaries_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _salaryStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriod(DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<StorageException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var startDate = DateTime.UtcNow;
+        var endDate = DateTime.UtcNow.AddDays(1);
+        var employeeId = Guid.NewGuid().ToString();
+        var listOriginal = new List<SalaryDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), DateTime.UtcNow, 10),
+            new(Guid.NewGuid().ToString(), DateTime.UtcNow.AddDays(1), 14),
+            new(Guid.NewGuid().ToString(), DateTime.UtcNow.AddDays(-1), 30),
+        };
+        _salaryStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(startDate, endDate, employeeId);
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _salaryStorageContract.Verify(x => x.GetList(startDate, endDate, employeeId), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _salaryStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), Guid.NewGuid().ToString());
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var dateTime = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(dateTime, dateTime, Guid.NewGuid().ToString()), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(dateTime, dateTime.AddSeconds(-1), Guid.NewGuid().ToString()), Throws.TypeOf<IncorrectDatesException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_EmployeeIdIsNUllOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_EmployeeIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), "workerId"), Throws.TypeOf<ValidationException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), Guid.NewGuid().ToString()), Throws.TypeOf<NullListException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalariesByEmployee_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _salaryStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.GetAllSalariesByPeriodByEmployee(DateTime.UtcNow, DateTime.UtcNow.AddDays(1), Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _salaryStorageContract.Verify(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_CalculateSalary_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        var saleSum = 200.0;
+        var postSalary = 2000.0;
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([new SaleDataModel(Guid.NewGuid().ToString(), employeeId, null, saleSum, DiscountType.None, 0, false, [])]);
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, postSalary, true, DateTime.UtcNow));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns([new EmployeeDataModel(employeeId, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)]);
+        var sum = 0.0;
+        var expectedSum = postSalary + saleSum * 0.1;
+        _salaryStorageContract.Setup(x => x.AddElement(It.IsAny<SalaryDataModel>()))
+            .Callback((SalaryDataModel x) =>
+            {
+                sum = x.Salary;
+            });
+        //Act
+        _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow);
+        //Assert
+        Assert.That(sum, Is.EqualTo(expectedSum));
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_WithSeveralWorkers_Test()
+    {
+        //Arrange
+        var employee1Id = Guid.NewGuid().ToString();
+        var employee2Id = Guid.NewGuid().ToString();
+        var employee3Id = Guid.NewGuid().ToString();
+        var list = new List<EmployeeDataModel>() {
+            new(employee1Id, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false),
+            new(employee2Id, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false),
+            new(employee3Id, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)
+        };
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([new SaleDataModel(Guid.NewGuid().ToString(), employee1Id, null, 1, DiscountType.None, 0, false, []),
+            new SaleDataModel(Guid.NewGuid().ToString(), employee1Id, null, 1, DiscountType.None, 0, false, []),
+            new SaleDataModel(Guid.NewGuid().ToString(), employee2Id, null, 1, DiscountType.None, 0, false, []),
+            new SaleDataModel(Guid.NewGuid().ToString(), employee3Id, null, 1, DiscountType.None, 0, false, []),
+            new SaleDataModel(Guid.NewGuid().ToString(), employee3Id, null, 1, DiscountType.None, 0, false, [])]);
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, 2000, true, DateTime.UtcNow));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns(list);
+        //Act
+        _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow);
+        //Assert
+        _salaryStorageContract.Verify(x => x.AddElement(It.IsAny<SalaryDataModel>()), Times.Exactly(list.Count));
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_WithoutSalesByWorker_Test()
+    {
+        //Arrange
+        var postSalary = 2000.0;
+        var employeeId = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([]);
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, postSalary, true, DateTime.UtcNow));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns([new EmployeeDataModel(employeeId, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)]);
+        var sum = 0.0;
+        var expectedSum = postSalary;
+        _salaryStorageContract.Setup(x => x.AddElement(It.IsAny<SalaryDataModel>()))
+            .Callback((SalaryDataModel x) =>
+            {
+                sum = x.Salary;
+            });
+        //Act
+        _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow);
+        //Assert
+        Assert.That(sum, Is.EqualTo(expectedSum));
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_SaleStorageReturnNull_ThrowException_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, 2000, true, DateTime.UtcNow));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns([new EmployeeDataModel(employeeId, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)]);
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow), Throws.TypeOf<NullListException>());
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_PostStorageReturnNull_ThrowException_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([new SaleDataModel(Guid.NewGuid().ToString(), employeeId, null, 200, DiscountType.None, 0, false, [])]);
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns([new EmployeeDataModel(employeeId, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)]);
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow), Throws.TypeOf<NullListException>());
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_WorkerStorageReturnNull_ThrowException_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([new SaleDataModel(Guid.NewGuid().ToString(), employeeId, null, 200, DiscountType.None, 0, false, [])]);
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, 2000, true, DateTime.UtcNow));
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow), Throws.TypeOf<NullListException>());
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_SaleStorageThrowException_ThrowException_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Throws(new StorageException(new InvalidOperationException()));
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, 2000, true, DateTime.UtcNow));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns([new EmployeeDataModel(employeeId, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)]);
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow), Throws.TypeOf<StorageException>());
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_PostStorageThrowException_ThrowException_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([new SaleDataModel(Guid.NewGuid().ToString(), employeeId, null, 200, DiscountType.None, 0, false, [])]);
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Throws(new StorageException(new InvalidOperationException()));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Returns([new EmployeeDataModel(employeeId, "Test", "123@gmail.com", Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow, false)]);
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow), Throws.TypeOf<StorageException>());
+    }
+
+    [Test]
+    public void CalculateSalaryByMounth_WorkerStorageThrowException_ThrowException_Test()
+    {
+        //Arrange
+        var employeeId = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime>(), It.IsAny<DateTime>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
+            .Returns([new SaleDataModel(Guid.NewGuid().ToString(), employeeId, null, 200, DiscountType.None, 0, false, [])]);
+        _postStorageContract.Setup(x => x.GetElementById(It.IsAny<string>()))
+            .Returns(new PostDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, 2000, true, DateTime.UtcNow));
+        _employeeStorageContract.Setup(x => x.GetList(It.IsAny<bool>(), It.IsAny<string?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<DateTime?>()))
+            .Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _salaryBusinessLogicContract.CalculateSalaryByMounth(DateTime.UtcNow), Throws.TypeOf<StorageException>());
+    }
+}

SquirrelContract/SquirrelTests/BusinessLogicContractsTests/SaleBusinessLogicContractTests.cs

@@ -0,0 +1,500 @@
+using Microsoft.Extensions.Logging;
+using Moq;
+using SquirrelBusinessLogic.Implementations;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelContract.StoragesContracts;
+
+namespace SquirrelTests.BusinessLogicContractsTests;
+
+[TestFixture]
+internal class SaleBusinessLogicContractTests
+{
+    private SaleBusinessLogicContract _saleBusinessLogicContract;
+    private Mock<ISaleStorageContract> _saleStorageContract;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUp()
+    {
+        _saleStorageContract = new Mock<ISaleStorageContract>();
+        _saleBusinessLogicContract = new SaleBusinessLogicContract(_saleStorageContract.Object, new Mock<ILogger>().Object);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _saleStorageContract.Reset();
+    }
+
+    [Test]
+    public void GetAllSalesByPeriod_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        var listOriginal = new List<SaleDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false,
+                [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)]),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+        };
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByPeriod(date, date.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _saleStorageContract.Verify(x => x.GetList(date, date.AddDays(1), null, null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByPeriod_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByPeriod(DateTime.UtcNow, DateTime.UtcNow.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByPeriod_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByPeriod(date, date), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByPeriod(date, date.AddSeconds(-1)), Throws.TypeOf<IncorrectDatesException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByPeriod_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByPeriod(DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<NullListException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByPeriod_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByPeriod(DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        var employeeId = Guid.NewGuid().ToString();
+        var listOriginal = new List<SaleDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false,
+                [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)]),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+        };
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(employeeId, date, date.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _saleStorageContract.Verify(x => x.GetList(date, date.AddDays(1), employeeId, null, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(Guid.NewGuid().ToString(), date, date), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(Guid.NewGuid().ToString(), date, date.AddSeconds(-1)), Throws.TypeOf<IncorrectDatesException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_EmployeeIdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(null, DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(string.Empty, DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ArgumentNullException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_EmployeeIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod("employeeId", DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ValidationException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<NullListException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByEmployeeByPeriod_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByEmployeeByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        var clientId = Guid.NewGuid().ToString();
+        var listOriginal = new List<SaleDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false,
+                [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)]),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+        };
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByClientByPeriod(clientId, date, date.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _saleStorageContract.Verify(x => x.GetList(date, date.AddDays(1), null, clientId, null), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByClientByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod(Guid.NewGuid().ToString(), date, date), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod(Guid.NewGuid().ToString(), date, date.AddSeconds(-1)), Throws.TypeOf<IncorrectDatesException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_ClientIdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod(null, DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod(string.Empty, DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ArgumentNullException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_ClientIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod("clientId", DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ValidationException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<NullListException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByClientByPeriod_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByClientByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_ReturnListOfRecords_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        var cocktailId = Guid.NewGuid().ToString();
+        var listOriginal = new List<SaleDataModel>()
+        {
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false,
+                [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)]),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+            new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false, []),
+        };
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns(listOriginal);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(cocktailId, date, date.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.EquivalentTo(listOriginal));
+        _saleStorageContract.Verify(x => x.GetList(date, date.AddDays(1), null, null, cocktailId), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_ReturnEmptyList_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Returns([]);
+        //Act
+        var list = _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1));
+        //Assert
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_IncorrectDates_ThrowException_Test()
+    {
+        //Arrange
+        var date = DateTime.UtcNow;
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(Guid.NewGuid().ToString(), date, date), Throws.TypeOf<IncorrectDatesException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(Guid.NewGuid().ToString(), date, date.AddSeconds(-1)), Throws.TypeOf<IncorrectDatesException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_CocktailIdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(null, DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(string.Empty, DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ArgumentNullException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_CocktailIdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod("CocktailId", DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<ValidationException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_ReturnNull_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<NullListException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetAllSalesByCocktailByPeriod_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetAllSalesByCocktailByPeriod(Guid.NewGuid().ToString(), DateTime.UtcNow, DateTime.UtcNow.AddDays(1)), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.GetList(It.IsAny<DateTime?>(), It.IsAny<DateTime?>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetSaleByData_GetById_ReturnRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var record = new SaleDataModel(id, Guid.NewGuid().ToString(), null, 10, DiscountType.None, 0, false,
+                [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)]);
+        _saleStorageContract.Setup(x => x.GetElementById(id)).Returns(record);
+        //Act
+        var element = _saleBusinessLogicContract.GetSaleByData(id);
+        //Assert
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.Id, Is.EqualTo(id));
+        _saleStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetSaleByData_EmptyData_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetSaleByData(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _saleBusinessLogicContract.GetSaleByData(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _saleStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetSaleByData_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetSaleByData("saleId"), Throws.TypeOf<ValidationException>());
+        _saleStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void GetSaleByData_GetById_NotFoundRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetSaleByData(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _saleStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void GetSaleByData_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.GetElementById(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.GetSaleByData(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.GetElementById(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertSale_CorrectRecord_Test()
+    {
+        //Arrange
+        var flag = false;
+        var record = new SaleDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.None, 10,
+            false, [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)]);
+        _saleStorageContract.Setup(x => x.AddElement(It.IsAny<SaleDataModel>()))
+            .Callback((SaleDataModel x) =>
+            {
+                flag = x.Id == record.Id && x.EmployeeId == record.EmployeeId && x.ClientId == record.ClientId &&
+                    x.SaleDate == record.SaleDate && x.Sum == record.Sum && x.DiscountType == record.DiscountType &&
+                    x.Discount == record.Discount && x.IsCancel == record.IsCancel && x.Cocktails.Count == record.Cocktails.Count &&
+                    x.Cocktails.First().CocktailId == record.Cocktails.First().CocktailId &&
+                    x.Cocktails.First().SaleId == record.Cocktails.First().SaleId &&
+                    x.Cocktails.First().Count == record.Cocktails.First().Count;
+            });
+        //Act
+        _saleBusinessLogicContract.InsertSale(record);
+        //Assert
+        _saleStorageContract.Verify(x => x.AddElement(It.IsAny<SaleDataModel>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void InsertSale_RecordWithExistsData_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.AddElement(It.IsAny<SaleDataModel>())).Throws(new ElementExistsException("Data", "Data"));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.InsertSale(new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(),
+            Guid.NewGuid().ToString(), 10, DiscountType.None, 10, false, [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)])), Throws.TypeOf<ElementExistsException>());
+        _saleStorageContract.Verify(x => x.AddElement(It.IsAny<SaleDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void InsertSale_NullRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.InsertSale(null), Throws.TypeOf<ArgumentNullException>());
+        _saleStorageContract.Verify(x => x.AddElement(It.IsAny<SaleDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertSale_InvalidRecord_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.InsertSale(new SaleDataModel("id", Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.None, 10, false, [])), Throws.TypeOf<ValidationException>());
+        _saleStorageContract.Verify(x => x.AddElement(It.IsAny<SaleDataModel>()), Times.Never);
+    }
+
+    [Test]
+    public void InsertSale_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.AddElement(It.IsAny<SaleDataModel>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.InsertSale(new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(),
+            Guid.NewGuid().ToString(), 10, DiscountType.None, 10, false, [new SaleCocktailDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 5)])), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.AddElement(It.IsAny<SaleDataModel>()), Times.Once);
+    }
+
+    [Test]
+    public void CancelSale_CorrectRecord_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        var flag = false;
+        _saleStorageContract.Setup(x => x.DelElement(It.Is((string x) => x == id))).Callback(() => { flag = true; });
+        //Act
+        _saleBusinessLogicContract.CancelSale(id);
+        //Assert
+        _saleStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+        Assert.That(flag);
+    }
+
+    [Test]
+    public void CancelSale_RecordWithIncorrectId_ThrowException_Test()
+    {
+        //Arrange
+        var id = Guid.NewGuid().ToString();
+        _saleStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new ElementNotFoundException(id));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.CancelSale(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+        _saleStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+
+    [Test]
+    public void CancelSale_IdIsNullOrEmpty_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.CancelSale(null), Throws.TypeOf<ArgumentNullException>());
+        Assert.That(() => _saleBusinessLogicContract.CancelSale(string.Empty), Throws.TypeOf<ArgumentNullException>());
+        _saleStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void CancelSale_IdIsNotGuid_ThrowException_Test()
+    {
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.CancelSale("id"), Throws.TypeOf<ValidationException>());
+        _saleStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Never);
+    }
+
+    [Test]
+    public void CancelSale_StorageThrowError_ThrowException_Test()
+    {
+        //Arrange
+        _saleStorageContract.Setup(x => x.DelElement(It.IsAny<string>())).Throws(new StorageException(new InvalidOperationException()));
+        //Act&Assert
+        Assert.That(() => _saleBusinessLogicContract.CancelSale(Guid.NewGuid().ToString()), Throws.TypeOf<StorageException>());
+        _saleStorageContract.Verify(x => x.DelElement(It.IsAny<string>()), Times.Once);
+    }
+}

SquirrelContract/SquirrelTests/DataModelsTests/ClientDataModelTests.cs

@@ -0,0 +1,70 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class ClientDataModelTests
+{
+    [Test]
+    public void IdIsNullOrEmptyTest()
+    {
+        var client = CreateDataModel(null, "fio", "number", 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+        client = CreateDataModel(string.Empty, "fio", "number", 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void IdIsNotGuidTest()
+    {
+        var client = CreateDataModel("id", "fio", "number", 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void FIOIsNullOrEmptyTest()
+    {
+        var client = CreateDataModel(Guid.NewGuid().ToString(), null, "number", 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+        client = CreateDataModel(Guid.NewGuid().ToString(), string.Empty, "number", 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PhoneNumberIsNullOrEmptyTest()
+    {
+        var client = CreateDataModel(Guid.NewGuid().ToString(), "fio", null, 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+        client = CreateDataModel(Guid.NewGuid().ToString(), "fio", string.Empty, 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PhoneNumberIsIncorrectTest()
+    {
+        var client = CreateDataModel(Guid.NewGuid().ToString(), "fio", "777", 10);
+        Assert.That(() => client.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var clientId = Guid.NewGuid().ToString();
+        var fio = "Fio";
+        var phoneNumber = "+7-777-777-77-77";
+        var discountSize = 11;
+        var buyer = CreateDataModel(clientId, fio, phoneNumber, discountSize);
+        Assert.That(() => buyer.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(buyer.Id, Is.EqualTo(clientId));
+            Assert.That(buyer.FIO, Is.EqualTo(fio));
+            Assert.That(buyer.PhoneNumber, Is.EqualTo(phoneNumber));
+            Assert.That(buyer.DiscountSize, Is.EqualTo(discountSize));
+        });
+    }
+
+    private static ClientDataModel CreateDataModel(string? id, string? fio, string? phoneNumber, double discountSize) =>
+        new(id, fio, phoneNumber, discountSize);
+}

SquirrelContract/SquirrelTests/DataModelsTests/CocktailDataModelTests.cs

@@ -0,0 +1,71 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class CocktailDataModelTests
+{
+    [Test]
+    public void IdIsNullOrEmptyTest()
+    {
+        var cocktail = CreateDataModel(null, "name", 10.5, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+        cocktail = CreateDataModel(string.Empty, "name", 10.5, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void IdIsNotGuidTest()
+    {
+        var cocktail = CreateDataModel("id", "name", 10.5, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+     
+    [Test]
+    public void CocktailNameIsNullOrEmptyTest()
+    {
+        var cocktail = CreateDataModel(Guid.NewGuid().ToString(), null, 10.5, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+        cocktail = CreateDataModel(Guid.NewGuid().ToString(), string.Empty, 10.5, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PriceIsLessOrZeroTest()
+    {
+        var cocktail = CreateDataModel(Guid.NewGuid().ToString(), null, 0, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+        cocktail = CreateDataModel(Guid.NewGuid().ToString(), string.Empty, -10.5, AlcoholType.Beer);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void BaseAlcoholIsNoneTest()
+    {
+        var cocktail = CreateDataModel(Guid.NewGuid().ToString(), null, 0, AlcoholType.None);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var cocktailId = Guid.NewGuid().ToString();
+        var cocktailName = "name";
+        var price = 10.5;
+        var baseAlcohol = AlcoholType.Vodka;
+        var cocktail = CreateDataModel(cocktailId, cocktailName, price, baseAlcohol);
+        Assert.That(() => cocktail.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(cocktail.Id, Is.EqualTo(cocktailId));
+            Assert.That(cocktail.CocktailName, Is.EqualTo(cocktailName));
+            Assert.That(cocktail.Price, Is.EqualTo(price));
+            Assert.That(cocktail.BaseAlcohol, Is.EqualTo(baseAlcohol));
+        });
+    }
+
+    private static CocktailDataModel CreateDataModel(string? id, string? cocktailName, double price, AlcoholType baseAlcohol) =>
+        new(id, cocktailName, price, baseAlcohol);
+}

SquirrelContract/SquirrelTests/DataModelsTests/CocktailHistoryDataModelTests.cs

@@ -0,0 +1,52 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class CocktailHistoryDataModelTests
+{
+    [Test]
+    public void CocktailIdIsNullOrEmptyTest()
+    {
+        var cocktail = CreateDataModel(null, 10);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+        cocktail = CreateDataModel(string.Empty, 10);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void ProductIdIsNotGuidTest()
+    {
+        var cocktail = CreateDataModel("id", 10);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void OldPriceIsLessOrZeroTest()
+    {
+        var cocktail = CreateDataModel(Guid.NewGuid().ToString(), 0);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+        cocktail = CreateDataModel(Guid.NewGuid().ToString(), -10);
+        Assert.That(() => cocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var cocktailId = Guid.NewGuid().ToString();
+        var oldPrice = 10;
+        var cocktailHistory = CreateDataModel(cocktailId, oldPrice);
+        Assert.That(() => cocktailHistory.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(cocktailHistory.CocktailId, Is.EqualTo(cocktailId));
+            Assert.That(cocktailHistory.OldPrice, Is.EqualTo(oldPrice));
+            Assert.That(cocktailHistory.ChangeDate, Is.LessThan(DateTime.UtcNow));
+            Assert.That(cocktailHistory.ChangeDate, Is.GreaterThan(DateTime.UtcNow.AddMinutes(-1)));
+        });
+    }
+
+    private static CocktailHistoryDataModel CreateDataModel(string? cocktailId, double oldPrice) =>
+        new(cocktailId, oldPrice);
+}

SquirrelContract/SquirrelTests/DataModelsTests/EmployeeDataModelTests.cs

@@ -0,0 +1,108 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class EmployeeDataModelTests
+{
+    [Test]
+    public void IdIsNullOrEmptyTest()
+    {
+        var employee = CreateDataModel(null, "fio", "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+        employee = CreateDataModel(string.Empty, "fio", "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void IdIsNotGuidTest()
+    {
+        var employee = CreateDataModel("id", "fio", "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void FIOIsNullOrEmptyTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), null, "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+        employee = CreateDataModel(Guid.NewGuid().ToString(), string.Empty, "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void EmailIsNullOrEmptyTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", null, Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+        employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", string.Empty, Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void EmailIsIncorrectTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PostIdIsNullOrEmptyTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail.com", null, DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+        employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail.com", string.Empty, DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PostIdIsNotGuidTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail.com", "postId", DateTime.Now.AddYears(-18), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void BirthDateIsNotCorrectTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-16).AddDays(1), DateTime.Now, false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void BirthDateAndEmploymentDateIsNotCorrectTest()
+    {
+        var employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now.AddYears(-18).AddDays(-1), false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+        employee = CreateDataModel(Guid.NewGuid().ToString(), "fio", "abc@gmail.com", Guid.NewGuid().ToString(), DateTime.Now.AddYears(-18), DateTime.Now.AddYears(-16), false);
+        Assert.That(() => employee.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var employeeId = Guid.NewGuid().ToString();
+        var fio = "fio";
+        var employeeEmail = "abc@gmail.com";
+        var postId = Guid.NewGuid().ToString();
+        var birthDate = DateTime.Now.AddYears(-18).AddDays(-1);
+        var employmentDate = DateTime.Now;
+        var isDelete = false;
+        var employee = CreateDataModel(employeeId, fio, employeeEmail, postId, birthDate, employmentDate, isDelete);
+        Assert.That(() => employee.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(employee.Id, Is.EqualTo(employeeId));
+            Assert.That(employee.FIO, Is.EqualTo(fio));
+            Assert.That(employee.Email, Is.EqualTo(employeeEmail));
+            Assert.That(employee.PostId, Is.EqualTo(postId));
+            Assert.That(employee.BirthDate, Is.EqualTo(birthDate));
+            Assert.That(employee.EmploymentDate, Is.EqualTo(employmentDate));
+            Assert.That(employee.IsDeleted, Is.EqualTo(isDelete));
+        });
+    }
+
+    private static EmployeeDataModel CreateDataModel(string? id, string? fio, string? email, string? postId, DateTime birthDate, DateTime employmentDate, bool isDeleted) =>
+        new(id, fio, email, postId, birthDate, employmentDate, isDeleted);
+}

SquirrelContract/SquirrelTests/DataModelsTests/PostDataModelTests.cs

@@ -0,0 +1,75 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class PostDataModelTests
+{
+    [Test]
+    public void IdIsNullOrEmptyTest()
+    {
+        var post = CreateDataModel(null, "name", PostType.Manager, 10, true, DateTime.UtcNow);
+        Assert.That(() => post.Validate(), Throws.TypeOf<ValidationException>());
+        post = CreateDataModel(string.Empty, "name", PostType.Manager, 10, true, DateTime.UtcNow);
+        Assert.That(() => post.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void IdIsNotGuidTest()
+    {
+        var post = CreateDataModel("id", "name", PostType.Manager, 10, true, DateTime.UtcNow);
+        Assert.That(() => post.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PostNameIsEmptyTest()
+    {
+        var manufacturer = CreateDataModel(Guid.NewGuid().ToString(), null, PostType.Manager, 10, true, DateTime.UtcNow);
+        Assert.That(() => manufacturer.Validate(), Throws.TypeOf<ValidationException>());
+        manufacturer = CreateDataModel(Guid.NewGuid().ToString(), string.Empty, PostType.Manager, 10, true, DateTime.UtcNow);
+        Assert.That(() => manufacturer.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void PostTypeIsNoneTest()
+    {
+        var post = CreateDataModel(Guid.NewGuid().ToString(), "name", PostType.None, 10, true, DateTime.UtcNow);
+        Assert.That(() => post.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void SalaryIsLessOrZeroTest()
+    {
+        var post = CreateDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, 0, true, DateTime.UtcNow);
+        Assert.That(() => post.Validate(), Throws.TypeOf<ValidationException>());
+        post = CreateDataModel(Guid.NewGuid().ToString(), "name", PostType.Manager, -10, true, DateTime.UtcNow);
+        Assert.That(() => post.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var postId = Guid.NewGuid().ToString();
+        var postName = "name";
+        var postType = PostType.Manager;
+        var salary = 10;
+        var isActual = false;
+        var changeDate = DateTime.UtcNow.AddDays(-1);
+        var post = CreateDataModel(postId, postName, postType, salary, isActual, changeDate);
+        Assert.That(() => post.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(post.Id, Is.EqualTo(postId));
+            Assert.That(post.PostName, Is.EqualTo(postName));
+            Assert.That(post.PostType, Is.EqualTo(postType));
+            Assert.That(post.Salary, Is.EqualTo(salary));
+            Assert.That(post.IsActual, Is.EqualTo(isActual));
+            Assert.That(post.ChangeDate, Is.EqualTo(changeDate));
+        });
+    }
+
+    private static PostDataModel CreateDataModel(string? id, string? postName, PostType postType, double salary, bool isActual, DateTime changeDate) =>
+        new(id, postName, postType, salary, isActual, changeDate);
+}

SquirrelContract/SquirrelTests/DataModelsTests/SalaryDataModelTests.cs

@@ -0,0 +1,52 @@
+using BarBelochkaContract.DataModels;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class SalaryDataModelTests
+{
+    [Test]
+    public void EmployeeIdIsEmptyTest()
+    {
+        var salary = CreateDataModel(null, DateTime.Now, 10);
+        Assert.That(() => salary.Validate(), Throws.TypeOf<ValidationException>());
+        salary = CreateDataModel(string.Empty, DateTime.Now, 10);
+        Assert.That(() => salary.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void EmployeeIdIsNotGuidTest()
+    {
+        var salary = CreateDataModel("employeeId", DateTime.Now, 10);
+        Assert.That(() => salary.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void SalaryIsLessOrZeroTest()
+    {
+        var salary = CreateDataModel(Guid.NewGuid().ToString(), DateTime.Now, 0);
+        Assert.That(() => salary.Validate(), Throws.TypeOf<ValidationException>());
+        salary = CreateDataModel(Guid.NewGuid().ToString(), DateTime.Now, -10);
+        Assert.That(() => salary.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var employeeId = Guid.NewGuid().ToString();
+        var salaryDate = DateTime.Now.AddDays(-3).AddMinutes(-5);
+        var enployeeSalary = 10;
+        var salary = CreateDataModel(employeeId, salaryDate, enployeeSalary);
+        Assert.That(() => salary.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(salary.EmployeeId, Is.EqualTo(employeeId));
+            Assert.That(salary.SalaryDate, Is.EqualTo(salaryDate));
+            Assert.That(salary.Salary, Is.EqualTo(enployeeSalary));
+        });
+    }
+
+    private static SalaryDataModel CreateDataModel(string? employeeId, DateTime salaryDate, double employeeSalary) =>
+        new(employeeId, salaryDate, employeeSalary);
+}

SquirrelContract/SquirrelTests/DataModelsTests/SaleCocktailDataModelTests.cs

@@ -0,0 +1,68 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class SaleCocktailDataModelTests
+{
+    [Test]
+    public void SaleIdIsNullOrEmptyTest()
+    {
+        var saleCocktail = CreateDataModel(null, Guid.NewGuid().ToString(), 10);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+        saleCocktail = CreateDataModel(string.Empty, Guid.NewGuid().ToString(), 10);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void SaleIdIsNotGuidTest()
+    {
+        var saleProduct = CreateDataModel("saleId", Guid.NewGuid().ToString(), 10);
+        Assert.That(() => saleProduct.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void CocktailIdIsNullOrEmptyTest()
+    {
+        var saleCocktail = CreateDataModel(Guid.NewGuid().ToString(), null, 10);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+        saleCocktail = CreateDataModel(string.Empty, Guid.NewGuid().ToString(), 10);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void ProductIdIsNotGuidTest()
+    {
+        var saleCocktail = CreateDataModel(Guid.NewGuid().ToString(), "productId", 10);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void CountIsLessOrZeroTest()
+    {
+        var saleCocktail = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 0);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+        saleCocktail = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), -10);
+        Assert.That(() => saleCocktail.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var saleId = Guid.NewGuid().ToString();
+        var cocktailId = Guid.NewGuid().ToString();
+        var count = 10;
+        var saleCocktail = CreateDataModel(saleId, cocktailId, count);
+        Assert.That(() => saleCocktail.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(saleCocktail.SaleId, Is.EqualTo(saleId));
+            Assert.That(saleCocktail.CocktailId, Is.EqualTo(cocktailId));
+            Assert.That(saleCocktail.Count, Is.EqualTo(count));
+        });
+    }
+
+    private static SaleCocktailDataModel CreateDataModel(string? saleId, string? cocktailId, int count) =>
+        new(saleId, cocktailId, count);
+}

SquirrelContract/SquirrelTests/DataModelsTests/SaleDataModelTests.cs

@@ -0,0 +1,97 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+
+namespace SquirrelTests.DataModelsTests;
+
+[TestFixture]
+internal class SaleDataModelTests
+{
+    [Test]
+    public void IdIsNullOrEmptyTest()
+    {
+        var sale = CreateDataModel(null, Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+        sale = CreateDataModel(string.Empty, Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void IdIsNotGuidTest()
+    {
+        var sale = CreateDataModel("id", Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+    [Test]
+    public void EmployeeIdIsNullOrEmptyTest()
+    {
+        var sale = CreateDataModel(Guid.NewGuid().ToString(), null, Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+        sale = CreateDataModel(Guid.NewGuid().ToString(), string.Empty, Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void EmployeeIdIsNotGuidTest()
+    {
+        var sale = CreateDataModel(Guid.NewGuid().ToString(), "employeeId", Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void ClientIdIsNotGuidTest()
+    {
+        var sale = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "clientId", 10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void SumIsLessOrZeroTest()
+    {
+        var sale = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 0, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+        sale = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), -10, DiscountType.OnSale, 10, false, CreateSubDataModel());
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void CocktailsIsNullOrEmptyTest()
+    {
+        var sale = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, null);
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+        sale = CreateDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10, DiscountType.OnSale, 10, false, []);
+        Assert.That(() => sale.Validate(), Throws.TypeOf<ValidationException>());
+    }
+
+    [Test]
+    public void AllFieldsIsCorrectTest()
+    {
+        var saleId = Guid.NewGuid().ToString();
+        var employeeId = Guid.NewGuid().ToString();
+        var clientId = Guid.NewGuid().ToString();
+        var sum = 10;
+        var discountType = DiscountType.Certificate;
+        var discount = 1;
+        var isCancel = true;
+        var cocktails = CreateSubDataModel();
+        var sale = CreateDataModel(saleId, employeeId, clientId, sum, discountType, discount, isCancel, cocktails);
+        Assert.That(() => sale.Validate(), Throws.Nothing);
+        Assert.Multiple(() =>
+        {
+            Assert.That(sale.Id, Is.EqualTo(saleId));
+            Assert.That(sale.EmployeeId, Is.EqualTo(employeeId));
+            Assert.That(sale.ClientId, Is.EqualTo(clientId));
+            Assert.That(sale.Sum, Is.EqualTo(sum));
+            Assert.That(sale.DiscountType, Is.EqualTo(discountType));
+            Assert.That(sale.Discount, Is.EqualTo(discount));
+            Assert.That(sale.IsCancel, Is.EqualTo(isCancel));
+            Assert.That(sale.Cocktails, Is.EquivalentTo(cocktails));
+        });
+    }
+
+    private static SaleDataModel CreateDataModel(string? id, string? employeeId, string? clientId, double sum, DiscountType discountType, double discount, bool isCancel, List<SaleCocktailDataModel>? cocktails) =>
+        new(id, employeeId, clientId, sum, discountType, discount, isCancel, cocktails);
+
+    private static List<SaleCocktailDataModel> CreateSubDataModel()
+        => [new(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 1)];
+}

SquirrelContract/SquirrelTests/Infrastructure/ConfigurationDatabaseTest.cs

@@ -0,0 +1,10 @@
+using SquirrelContract.Infastructure;
+
+namespace SquirrelTests.Infrastructure;
+
+internal class ConfigurationDatabaseTest : IConfigurationDatabase
+{
+    public string ConnectionString =>
+    "Host=127.0.0.1;Port=5432;Database=SquirrelTest;Username=postgres;Password=postgres;";
+}
+

SquirrelContract/SquirrelTests/SquirrelTests.csproj

@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="NUnit" Version="4.2.2" />
+    <PackageReference Include="NUnit.Analyzers" Version="4.4.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\SquirrelBusinessLogic\SquirrelBusinessLogic.csproj" />
+    <ProjectReference Include="..\SquirrelContract\SquirrelContract.csproj" />
+    <ProjectReference Include="..\SquirrelDatabase\SquirrelDatabase.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="NUnit.Framework" />
+  </ItemGroup>
+
+</Project>

SquirrelContract/SquirrelTests/StorageContracts/BaseStorageContractTest.cs

@@ -0,0 +1,25 @@
+using SquirrelTests.Infrastructure;
+using SquirrelDatabase;
+
+namespace SquirrelTests.StoragesContracts;
+
+internal abstract class BaseStorageContractTest
+{
+	protected SquirrelDbContext SquirrelDbContext { get; private set; }
+
+	[OneTimeSetUp]
+	public void OneTimeSetUp()
+	{
+		SquirrelDbContext = new SquirrelDbContext(new ConfigurationDatabaseTest());
+
+		SquirrelDbContext.Database.EnsureDeleted();
+		SquirrelDbContext.Database.EnsureCreated();
+	}
+
+	[OneTimeTearDown]
+	public void OneTimeTearDown()
+	{
+		SquirrelDbContext.Database.EnsureDeleted();
+		SquirrelDbContext.Dispose();
+	}
+}

SquirrelContract/SquirrelTests/StorageContracts/ClientStorageContractTests.cs

@@ -0,0 +1,214 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelDatabase.Implementations;
+using SquirrelDatabase.Models;
+using Microsoft.EntityFrameworkCore;
+using SquirrelContract.StoragesContracts;
+using SquirrelTests.StoragesContracts;
+
+namespace SquirrelTests.StorageContracts;
+
+[TestFixture]
+internal class ClientStorageContractTests : BaseStorageContractTest
+{
+	private IClientStorageContract _clientStorageContract;
+
+	[SetUp]
+	public void SetUp()
+	{
+		_clientStorageContract = new ClientStorageContract(SquirrelDbContext);
+	}
+
+	[TearDown]
+	public void TearDown()
+	{
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Sales\" CASCADE;");
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Employees\" CASCADE;");
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Clients\" CASCADE;");
+	}
+
+	[Test]
+	public void Try_GetList_WhenHaveRecords_Test()
+	{
+		var client = InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString(), phoneNumber: "+5-555-555-55-55");
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString(), phoneNumber: "+6-666-666-66-66");
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString(), phoneNumber: "+7-777-777-77-77");
+		var list = _clientStorageContract.GetList();
+		Assert.That(list, Is.Not.Null);
+		Assert.That(list, Has.Count.EqualTo(3));
+		AssertElement(list.First(x => x.Id == client.Id), client);
+	}
+
+	[Test]
+	public void Try_GetList_WhenNoRecords_Test()
+	{
+		var list = _clientStorageContract.GetList();
+		Assert.That(list, Is.Not.Null);
+		Assert.That(list, Is.Empty);
+	}
+
+	[Test]
+	public void Try_GetElementById_WhenHaveRecord_Test()
+	{
+		var client = InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		AssertElement(_clientStorageContract.GetElementById(client.Id), client);
+	}
+
+	[Test]
+	public void Try_GetElementById_WhenNoRecord_Test()
+	{
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		Assert.That(() => _clientStorageContract.GetElementById(Guid.NewGuid().ToString()), Is.Null);
+	}
+
+	[Test]
+	public void Try_GetElementByFIO_WhenHaveRecord_Test()
+	{
+		var client = InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		AssertElement(_clientStorageContract.GetElementByFIO(client.FIO), client);
+	}
+
+	[Test]
+	public void Try_GetElementByFIO_WhenNoRecord_Test()
+	{
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		Assert.That(() => _clientStorageContract.GetElementByFIO("New Fio"), Is.Null);
+	}
+
+	[Test]
+	public void Try_GetElementByPhoneNumber_WhenHaveRecord_Test()
+	{
+		var client = InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		AssertElement(_clientStorageContract.GetElementByPhoneNumber(client.PhoneNumber), client);
+	}
+
+	[Test]
+	public void Try_GetElementByPhoneNumber_WhenNoRecord_Test()
+	{
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		Assert.That(() => _clientStorageContract.GetElementByPhoneNumber("+8-888-888-88-88"), Is.Null);
+	}
+
+	[Test]
+	public void Try_AddElement_Test()
+	{
+		var client = CreateModel(Guid.NewGuid().ToString());
+		_clientStorageContract.AddElement(client);
+		AssertElement(GetClientFromDatabase(client.Id), client);
+	}
+
+	[Test]
+	public void Try_AddElement_WhenHaveRecordWithSameId_Test()
+	{
+		var client = CreateModel(Guid.NewGuid().ToString(), "New Fio", "+5-555-555-55-55", 500);
+		InsertClientToDatabaseAndReturn(client.Id);
+		Assert.That(() => _clientStorageContract.AddElement(client), Throws.TypeOf<ElementExistsException>());
+	}
+
+	[Test]
+	public void Try_AddElement_WhenHaveRecordWithSamePhoneNumber_Test()
+	{
+		var client = CreateModel(Guid.NewGuid().ToString(), "New Fio", "+5-555-555-55-55", 500);
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString(), phoneNumber: client.PhoneNumber);
+		Assert.That(() => _clientStorageContract.AddElement(client), Throws.TypeOf<ElementExistsException>());
+	}
+
+	[Test]
+	public void Try_UpdElement_Test()
+	{
+		var client = CreateModel(Guid.NewGuid().ToString(), "New Fio", "+5-555-555-55-55", 500);
+		InsertClientToDatabaseAndReturn(client.Id);
+		_clientStorageContract.UpdElement(client);
+		AssertElement(GetClientFromDatabase(client.Id), client);
+	}
+
+	[Test]
+	public void Try_UpdElement_WhenNoRecordWithThisId_Test()
+	{
+		Assert.That(() => _clientStorageContract.UpdElement(CreateModel(Guid.NewGuid().ToString())), Throws.TypeOf<ElementNotFoundException>());
+	}
+
+	[Test]
+	public void Try_UpdElement_WhenHaveRecordWithSamePhoneNumber_Test()
+	{
+		var client = CreateModel(Guid.NewGuid().ToString(), "New Fio", "+5-555-555-55-55", 500);
+		InsertClientToDatabaseAndReturn(client.Id, phoneNumber: "+7-777-777-77-77");
+		InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString(), phoneNumber: client.PhoneNumber);
+		Assert.That(() => _clientStorageContract.UpdElement(client), Throws.TypeOf<ElementExistsException>());
+	}
+
+	[Test]
+	public void Try_DelElement_Test()
+	{
+		var client = InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		_clientStorageContract.DelElement(client.Id);
+		var element = GetClientFromDatabase(client.Id);
+		Assert.That(element, Is.Null);
+	}
+
+	[Test]
+	public void Try_DelElement_WhenHaveSalesByThisClient_Test()
+	{
+		var client = InsertClientToDatabaseAndReturn(Guid.NewGuid().ToString());
+		var employeeId = Guid.NewGuid().ToString();
+		SquirrelDbContext.Employees.Add(new Employee() { Id = employeeId, FIO = "test", PostId = Guid.NewGuid().ToString(), Email = "abc@gmail.com" });
+		SquirrelDbContext.Sales.Add(new Sale() { Id = Guid.NewGuid().ToString(), EmployeeId = employeeId, ClientId = client.Id, Sum = 10, DiscountType = DiscountType.None, Discount = 0 });
+		SquirrelDbContext.Sales.Add(new Sale() { Id = Guid.NewGuid().ToString(), EmployeeId = employeeId, ClientId = client.Id, Sum = 10, DiscountType = DiscountType.None, Discount = 0 });
+		SquirrelDbContext.SaveChanges();
+		var salesBeforeDelete = SquirrelDbContext.Sales.Where(x => x.ClientId == client.Id).ToArray();
+		_clientStorageContract.DelElement(client.Id);
+		var element = GetClientFromDatabase(client.Id);
+		var salesAfterDelete = SquirrelDbContext.Sales.Where(x => x.ClientId == client.Id).ToArray();
+		Assert.Multiple(() =>
+		{
+			Assert.That(element, Is.Null);
+			Assert.That(salesBeforeDelete, Has.Length.EqualTo(2));
+			Assert.That(salesAfterDelete, Is.Empty);
+			Assert.That(SquirrelDbContext.Sales.Count(), Is.EqualTo(2));
+		});
+	}
+
+	[Test]
+	public void Try_DelElement_WhenNoRecordWithThisId_Test()
+	{
+		Assert.That(() => _clientStorageContract.DelElement(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+	}
+
+	private Client InsertClientToDatabaseAndReturn(string id, string fio = "test", string phoneNumber = "+7-777-777-77-77", double discountSize = 10)
+	{
+		var client = new Client() { Id = id, FIO = fio, PhoneNumber = phoneNumber, DiscountSize = discountSize };
+		SquirrelDbContext.Clients.Add(client);
+		SquirrelDbContext.SaveChanges();
+		return client;
+	}
+
+	private static void AssertElement(ClientDataModel? actual, Client expected)
+	{
+		Assert.That(actual, Is.Not.Null);
+		Assert.Multiple(() =>
+		{
+			Assert.That(actual.Id, Is.EqualTo(expected.Id));
+			Assert.That(actual.FIO, Is.EqualTo(expected.FIO));
+			Assert.That(actual.PhoneNumber, Is.EqualTo(expected.PhoneNumber));
+			Assert.That(actual.DiscountSize, Is.EqualTo(expected.DiscountSize));
+		});
+	}
+
+	private static ClientDataModel CreateModel(string id, string fio = "test", string phoneNumber = "+7-777-777-77-77", double discountSize = 10)
+		=> new(id, fio, phoneNumber, discountSize);
+
+	private Client? GetClientFromDatabase(string id) => SquirrelDbContext.Clients.FirstOrDefault(x => x.Id == id);
+
+	private static void AssertElement(Client? actual, ClientDataModel expected)
+	{
+		Assert.That(actual, Is.Not.Null);
+		Assert.Multiple(() =>
+		{
+			Assert.That(actual.Id, Is.EqualTo(expected.Id));
+			Assert.That(actual.FIO, Is.EqualTo(expected.FIO));
+			Assert.That(actual.PhoneNumber, Is.EqualTo(expected.PhoneNumber));
+			Assert.That(actual.DiscountSize, Is.EqualTo(expected.DiscountSize));
+		});
+	}
+}

SquirrelContract/SquirrelTests/StorageContracts/CocktailStorageContractTests.cs

@@ -0,0 +1,208 @@
+using Microsoft.EntityFrameworkCore;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelDatabase.Implementations;
+using SquirrelDatabase.Models;
+using SquirrelTests.StoragesContracts;
+using static NUnit.Framework.Internal.OSPlatform;
+
+namespace SquirrelTests.StorageContracts;
+
+[TestFixture]
+internal class CocktailStorageContractTests : BaseStorageContractTest
+{
+    private CocktailStorageContract _cocktailStorageContract;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _cocktailStorageContract = new CocktailStorageContract(SquirrelDbContext);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Cocktails\" CASCADE;");
+    }
+
+    [Test]
+    public void Try_GetList_WhenHaveRecords_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1");
+        InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 2");
+        InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 3");
+        var list = _cocktailStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+        AssertElement(list.First(x => x.Id == cocktail.Id), cocktail);
+    }
+
+    [Test]
+    public void Try_GetList_WhenNoRecords_Test()
+    {
+        var list = _cocktailStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.Empty);
+    }
+
+    [Test]
+    public void Try_GetHistoryByCocktailId_WhenHaveRecords_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1");
+        InsertCocktailHistoryToDatabaseAndReturn(cocktail.Id, 20, DateTime.UtcNow.AddDays(-1));
+        InsertCocktailHistoryToDatabaseAndReturn(cocktail.Id, 30, DateTime.UtcNow.AddMinutes(-10));
+        InsertCocktailHistoryToDatabaseAndReturn(cocktail.Id, 40, DateTime.UtcNow.AddDays(1));
+        var list = _cocktailStorageContract.GetHistoryByCocktailId(cocktail.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+    }
+
+    [Test]
+    public void Try_GetHistoryByCocktailId_WhenNoRecords_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1");
+        InsertCocktailHistoryToDatabaseAndReturn(cocktail.Id, 20, DateTime.UtcNow.AddDays(-1));
+        InsertCocktailHistoryToDatabaseAndReturn(cocktail.Id, 30, DateTime.UtcNow.AddMinutes(-10));
+        InsertCocktailHistoryToDatabaseAndReturn(cocktail.Id, 40, DateTime.UtcNow.AddDays(1));
+        var list = _cocktailStorageContract.GetHistoryByCocktailId(Guid.NewGuid().ToString());
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenHaveRecord_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString());
+        AssertElement(_cocktailStorageContract.GetElementById(cocktail.Id), cocktail);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenNoRecord_Test()
+    {
+        InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString());
+        Assert.That(() => _cocktailStorageContract.GetElementById(Guid.NewGuid().ToString()), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementByName_WhenHaveRecord_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString());
+        AssertElement(_cocktailStorageContract.GetElementByName(cocktail.CocktailName), cocktail);
+    }
+
+    [Test]
+    public void Try_GetElementByName_WhenNoRecord_Test()
+    {
+        InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString());
+        Assert.That(() => _cocktailStorageContract.GetElementByName("name"), Is.Null);
+    }
+
+    [Test]
+    public void Try_AddElement_Test()
+    {
+        var cocktail = CreateModel(Guid.NewGuid().ToString());
+        _cocktailStorageContract.AddElement(cocktail);
+        AssertElement(GetCocktailFromDatabaseById(cocktail.Id), cocktail);
+    }
+
+    [Test]
+    public void Try_AddElement_WhenHaveRecordWithSameId_Test()
+    {
+        var cocktail = CreateModel(Guid.NewGuid().ToString());
+        InsertCocktailToDatabaseAndReturn(cocktail.Id, cocktailName: "name unique");
+        Assert.That(() => _cocktailStorageContract.AddElement(cocktail), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_AddElement_WhenHaveRecordWithSameName_Test()
+    {
+        var cocktail = CreateModel(Guid.NewGuid().ToString(), "name unique");
+        InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), cocktailName: cocktail.CocktailName);
+        Assert.That(() => _cocktailStorageContract.AddElement(cocktail), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_Test()
+    {
+        var cocktail = CreateModel(Guid.NewGuid().ToString(), "new name", AlcoholType.Vodka);
+        InsertCocktailToDatabaseAndReturn(cocktail.Id);
+        _cocktailStorageContract.UpdElement(cocktail);
+        AssertElement(GetCocktailFromDatabaseById(cocktail.Id), cocktail);
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _cocktailStorageContract.UpdElement(CreateModel(Guid.NewGuid().ToString())), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenHaveRecordWithSameName_Test()
+    {
+        var cocktail = CreateModel(Guid.NewGuid().ToString(), "name unique");
+        InsertCocktailToDatabaseAndReturn(cocktail.Id, cocktailName: "name");
+        InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString(), cocktailName: cocktail.CocktailName);
+        Assert.That(() => _cocktailStorageContract.UpdElement(cocktail), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_DelElement_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn(Guid.NewGuid().ToString());
+        _cocktailStorageContract.DelElement(cocktail.Id);
+        var element = GetCocktailFromDatabaseById(cocktail.Id);
+        Assert.That(element, Is.Null);
+    }
+
+    [Test]
+    public void Try_DelElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _cocktailStorageContract.DelElement(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    private Cocktail InsertCocktailToDatabaseAndReturn(string id, string cocktailName = "test", AlcoholType baseAlcohol = AlcoholType.Vodka, double price = 1)
+    {
+        var cocktail = new Cocktail() { Id = id, CocktailName = cocktailName, BaseAlcohol = baseAlcohol, Price = price };
+        SquirrelDbContext.Cocktails.Add(cocktail);
+        SquirrelDbContext.SaveChanges();
+        return cocktail;
+    }
+
+    private CocktailHistory InsertCocktailHistoryToDatabaseAndReturn(string cocktailId, double price, DateTime changeDate)
+    {
+        var cocktailHistory = new CocktailHistory() { Id = Guid.NewGuid().ToString(), CocktailId = cocktailId, OldPrice = price, ChangeDate = changeDate };
+        SquirrelDbContext.CocktailHistories.Add(cocktailHistory);
+        SquirrelDbContext.SaveChanges();
+        return cocktailHistory;
+    }
+
+    private static void AssertElement(CocktailDataModel? actual, Cocktail expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.Id));
+            Assert.That(actual.CocktailName, Is.EqualTo(expected.CocktailName));
+            Assert.That(actual.BaseAlcohol, Is.EqualTo(expected.BaseAlcohol));
+            Assert.That(actual.Price, Is.EqualTo(expected.Price));
+        });
+    }
+
+    private static CocktailDataModel CreateModel(string id, string cocktailName = "test", AlcoholType baseAlcohol = AlcoholType.Beer, double price = 1)
+        => new(id, cocktailName, price, baseAlcohol);
+
+    private Cocktail? GetCocktailFromDatabaseById(string id) => SquirrelDbContext.Cocktails.FirstOrDefault(x => x.Id == id);
+
+    private static void AssertElement(Cocktail? actual, CocktailDataModel expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.Id));
+            Assert.That(actual.CocktailName, Is.EqualTo(expected.CocktailName));
+            Assert.That(actual.BaseAlcohol, Is.EqualTo(expected.BaseAlcohol));
+            Assert.That(actual.Price, Is.EqualTo(expected.Price));
+        });
+    }
+}

SquirrelContract/SquirrelTests/StorageContracts/EmployeeStorageContractTests.cs

@@ -0,0 +1,230 @@
+using Microsoft.EntityFrameworkCore;
+
+using SquirrelContract.Exceptions;
+using SquirrelDatabase.Implementations;
+using SquirrelDatabase.Models;
+using SquirrelContract.DataModels;
+using SquirrelTests.StoragesContracts;
+using System.ComponentModel.DataAnnotations;
+
+namespace SquirrelTests.StorageContracts;
+
+[TestFixture]
+internal class EmployeeStorageContractTests : BaseStorageContractTest
+{
+    private EmployeeStorageContract _employeeStorageContract;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _employeeStorageContract = new EmployeeStorageContract(SquirrelDbContext);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Employees\" CASCADE;");
+    }
+
+    [Test]
+    public void Try_GetList_WhenHaveRecords_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 1", "abc@gmail.com");
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 2", "abc@gmail.com");
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 3", "abc@gmail.com");
+        var list = _employeeStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+        AssertElement(list.First(), employee);
+    }
+
+    [Test]
+    public void Try_GetList_WhenNoRecords_Test()
+    {
+        var list = _employeeStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.Empty);
+    }
+
+    [Test]
+    public void Try_GetList_ByPostId_Test()
+    {
+        var postId = Guid.NewGuid().ToString();
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 1", "abc@gmail.com", postId);
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 2", "abc@gmail.com", postId);
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 3", "abc@gmail.com");
+        var list = _employeeStorageContract.GetList(postId: postId);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+        Assert.That(list.All(x => x.PostId == postId));
+    }
+
+    [Test]
+    public void Try_GetList_ByBirthDate_Test()
+    {
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 1", "abc@gmail.com", birthDate: DateTime.UtcNow.AddYears(-25));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 2", "abc@gmail.com", birthDate: DateTime.UtcNow.AddYears(-21));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 3", "abc@gmail.com", birthDate: DateTime.UtcNow.AddYears(-20));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 4", "abc@gmail.com", birthDate: DateTime.UtcNow.AddYears(-19));
+        var list = _employeeStorageContract.GetList(fromBirthDate: DateTime.UtcNow.AddYears(-21).AddMinutes(-1), toBirthDate: DateTime.UtcNow.AddYears(-20).AddMinutes(1));
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+    }
+
+    [Test]
+    public void Try_GetList_ByEmploymentDate_Test()
+    {
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 1", "abc@gmail.com", employmentDate: DateTime.UtcNow.AddDays(-2));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 2", "abc@gmail.com", employmentDate: DateTime.UtcNow.AddDays(-1));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 3", "abc@gmail.com", employmentDate: DateTime.UtcNow.AddDays(1));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 4", "abc@gmail.com", employmentDate: DateTime.UtcNow.AddDays(2));
+        var list = _employeeStorageContract.GetList(fromEmploymentDate: DateTime.UtcNow.AddDays(-1).AddMinutes(-1), toEmploymentDate: DateTime.UtcNow.AddDays(1).AddMinutes(1));
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+    }
+
+    [Test]
+    public void Try_GetList_ByAllParameters_Test()
+    {
+        var postId = Guid.NewGuid().ToString();
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 1", "abc@gmail.com", postId, birthDate: DateTime.UtcNow.AddYears(-25), employmentDate: DateTime.UtcNow.AddDays(-2));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 2", "abc@gmail.com", postId, birthDate: DateTime.UtcNow.AddYears(-22), employmentDate: DateTime.UtcNow.AddDays(-1));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 3", "abc@gmail.com", postId, birthDate: DateTime.UtcNow.AddYears(-21), employmentDate: DateTime.UtcNow.AddDays(-1));
+        InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString(), "fio 4", "abc@gmail.com", birthDate: DateTime.UtcNow.AddYears(-20), employmentDate: DateTime.UtcNow.AddDays(1));
+        var list = _employeeStorageContract.GetList(postId: postId, fromBirthDate: DateTime.UtcNow.AddYears(-21).AddMinutes(-1), toBirthDate: DateTime.UtcNow.AddYears(-20).AddMinutes(1), fromEmploymentDate: DateTime.UtcNow.AddDays(-1).AddMinutes(-1), toEmploymentDate: DateTime.UtcNow.AddDays(1).AddMinutes(1));
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(1));
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenHaveRecord_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString());
+        AssertElement(_employeeStorageContract.GetElementById(employee.Id), employee);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenNoRecord_Test()
+    {
+        Assert.That(() => _employeeStorageContract.GetElementById(Guid.NewGuid().ToString()), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementByFIO_WhenHaveRecord_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString());
+        AssertElement(_employeeStorageContract.GetElementByFIO(employee.FIO), employee);
+    }
+
+    [Test]
+    public void Try_GetElementByFIO_WhenNoRecord_Test()
+    {
+        Assert.That(() => _employeeStorageContract.GetElementByFIO("New Fio"), Is.Null);
+    }
+
+    [Test]
+    public void Try_AddElement_Test()
+    {
+        var employee = CreateModel(Guid.NewGuid().ToString());
+        _employeeStorageContract.AddElement(employee);
+        AssertElement(GetEmployeeFromDatabase(employee.Id), employee);
+    }
+
+    [Test]
+    public void Try_AddElement_WhenHaveRecordWithSameId_Test()
+    {
+        var employee = CreateModel(Guid.NewGuid().ToString());
+        InsertEmployeeToDatabaseAndReturn(employee.Id);
+        Assert.That(() => _employeeStorageContract.AddElement(employee), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_Test()
+    {
+        var employee = CreateModel(Guid.NewGuid().ToString(), "New Fio");
+        InsertEmployeeToDatabaseAndReturn(employee.Id);
+        _employeeStorageContract.UpdElement(employee);
+        AssertElement(GetEmployeeFromDatabase(employee.Id), employee);
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _employeeStorageContract.UpdElement(CreateModel(Guid.NewGuid().ToString())), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenNoRecordWasDeleted_Test()
+    {
+        var employee = CreateModel(Guid.NewGuid().ToString());
+        InsertEmployeeToDatabaseAndReturn(employee.Id, isDeleted: true);
+        Assert.That(() => _employeeStorageContract.UpdElement(employee), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_DelElement_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn(Guid.NewGuid().ToString());
+        _employeeStorageContract.DelElement(employee.Id);
+        var element = GetEmployeeFromDatabase(employee.Id);
+        Assert.That(element, Is.Not.Null);
+        Assert.That(element.IsDeleted);
+    }
+
+    [Test]
+    public void Try_DelElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _employeeStorageContract.DelElement(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_DelElement_WhenNoRecordWasDeleted_Test()
+    {
+        var employee = CreateModel(Guid.NewGuid().ToString());
+        InsertEmployeeToDatabaseAndReturn(employee.Id, isDeleted: true);
+        Assert.That(() => _employeeStorageContract.DelElement(employee.Id), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    private Employee InsertEmployeeToDatabaseAndReturn(string id, string fio = "test", string email = "abc@mail.ru", string? postId = null, DateTime? birthDate = null, DateTime? employmentDate = null, bool isDeleted = false)
+    {
+        var employee = new Employee() { Id = id, FIO = fio, Email = email, PostId = postId ?? Guid.NewGuid().ToString(), BirthDate = birthDate ?? DateTime.UtcNow.AddYears(-20), EmploymentDate = employmentDate ?? DateTime.UtcNow, IsDeleted = isDeleted };
+        SquirrelDbContext.Employees.Add(employee);
+        SquirrelDbContext.SaveChanges();
+        return employee;
+    }
+
+    private static void AssertElement(EmployeeDataModel? actual, Employee expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.Id));
+            Assert.That(actual.PostId, Is.EqualTo(expected.PostId));
+            Assert.That(actual.FIO, Is.EqualTo(expected.FIO));
+            Assert.That(actual.Email, Is.EqualTo(expected.Email));
+            Assert.That(actual.BirthDate, Is.EqualTo(expected.BirthDate));
+            Assert.That(actual.EmploymentDate, Is.EqualTo(expected.EmploymentDate));
+            Assert.That(actual.IsDeleted, Is.EqualTo(expected.IsDeleted));
+        });
+    }
+
+    private static EmployeeDataModel CreateModel(string id, string fio = "fio", string email = "abc@mail.ru", string? postId = null, DateTime? birthDate = null, DateTime? employmentDate = null, bool isDeleted = false) =>
+        new(id, fio, email, postId ?? Guid.NewGuid().ToString(), birthDate ?? DateTime.UtcNow.AddYears(-20), employmentDate ?? DateTime.UtcNow, isDeleted);
+
+    private Employee? GetEmployeeFromDatabase(string id) => SquirrelDbContext.Employees.FirstOrDefault(x => x.Id == id);
+
+    private static void AssertElement(Employee? actual, EmployeeDataModel expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.Id));
+            Assert.That(actual.PostId, Is.EqualTo(expected.PostId));
+            Assert.That(actual.FIO, Is.EqualTo(expected.FIO));
+            Assert.That(actual.Email, Is.EqualTo(expected.Email));  
+            Assert.That(actual.BirthDate, Is.EqualTo(expected.BirthDate));
+            Assert.That(actual.EmploymentDate, Is.EqualTo(expected.EmploymentDate));
+            Assert.That(actual.IsDeleted, Is.EqualTo(expected.IsDeleted));
+        });
+    }
+}

SquirrelContract/SquirrelTests/StorageContracts/PostStorageContractTests.cs

@@ -0,0 +1,318 @@
+using Microsoft.EntityFrameworkCore;
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelDatabase.Implementations;
+using SquirrelDatabase.Models;
+using SquirrelTests.StoragesContracts;
+
+namespace SquirrelTests.StorageContracts;
+
+[TestFixture]
+internal class PostStorageContractTests : BaseStorageContractTest
+{
+    private PostStorageContract _postStorageContract;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _postStorageContract = new PostStorageContract(SquirrelDbContext);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Posts\" CASCADE;");
+    }
+
+    [Test]
+    public void Try_GetList_WhenHaveRecords_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1");
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 2");
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 3");
+        var list = _postStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+        AssertElement(list.First(x => x.Id == post.PostId), post);
+    }
+
+    [Test]
+    public void Try_GetList_WhenNoRecords_Test()
+    {
+        var list = _postStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.Empty);
+    }
+
+    [Test]
+    public void Try_GetList_OnlyActual_Test()
+    {
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1", isActual: true);
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 2", isActual: true);
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 3", isActual: false);
+        var list = _postStorageContract.GetList(onlyActual: true);
+        Assert.That(list, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(list, Has.Count.EqualTo(2));
+            Assert.That(!list.Any(x => !x.IsActual));
+        });
+    }
+
+    [Test]
+    public void Try_GetList_IncludeNoActual_Test()
+    {
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1", isActual: true);
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 2", isActual: true);
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 3", isActual: false);
+        var list = _postStorageContract.GetList(onlyActual: false);
+        Assert.That(list, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(list, Has.Count.EqualTo(3));
+            Assert.That(list.Count(x => x.IsActual), Is.EqualTo(2));
+            Assert.That(list.Count(x => !x.IsActual), Is.EqualTo(1));
+        });
+    }
+
+    [Test]
+    public void Try_GetPostWithHistory_WhenHaveRecords_Test()
+    {
+        var postId = Guid.NewGuid().ToString();
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1", isActual: true);
+        InsertPostToDatabaseAndReturn(postId, "name 2", isActual: true);
+        InsertPostToDatabaseAndReturn(postId, "name 2", isActual: false);
+        var list = _postStorageContract.GetPostWithHistory(postId);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+    }
+
+    [Test]
+    public void Try_GetPostWithHistory_WhenNoRecords_Test()
+    {
+        var postId = Guid.NewGuid().ToString();
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), "name 1", isActual: true);
+        InsertPostToDatabaseAndReturn(postId, "name 2", isActual: true);
+        InsertPostToDatabaseAndReturn(postId, "name 2", isActual: false);
+        var list = _postStorageContract.GetPostWithHistory(Guid.NewGuid().ToString());
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(0));
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenHaveRecord_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString());
+        AssertElement(_postStorageContract.GetElementById(post.PostId), post);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenNoRecord_Test()
+    {
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString());
+        Assert.That(() => _postStorageContract.GetElementById(Guid.NewGuid().ToString()), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenRecordHasDeleted_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), isActual: false);
+        Assert.That(() => _postStorageContract.GetElementById(post.PostId), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenTrySearchById_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString());
+        Assert.That(() => _postStorageContract.GetElementById(post.Id), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementByName_WhenHaveRecord_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString());
+        AssertElement(_postStorageContract.GetElementByName(post.PostName), post);
+    }
+
+    [Test]
+    public void Try_GetElementByName_WhenNoRecord_Test()
+    {
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString());
+        Assert.That(() => _postStorageContract.GetElementByName("name"), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementByName_WhenRecordHasDeleted_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), isActual: false);
+        Assert.That(() => _postStorageContract.GetElementById(post.PostName), Is.Null);
+    }
+
+    [Test]
+    public void Try_AddElement_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString(), isActual: true);
+        _postStorageContract.AddElement(post);
+        AssertElement(GetPostFromDatabaseByPostId(post.Id), post);
+    }
+
+    [Test]
+    public void Try_AddElement_WhenActualIsFalse_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString(), isActual: false);
+        Assert.That(() => _postStorageContract.AddElement(post), Throws.Nothing);
+        AssertElement(GetPostFromDatabaseByPostId(post.Id), CreateModel(post.Id, isActual: true));
+    }
+
+    [Test]
+    public void Try_AddElement_WhenHaveRecordWithSameName_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString(), "name unique", isActual: true);
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), postName: post.PostName, isActual: true);
+        Assert.That(() => _postStorageContract.AddElement(post), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_AddElement_WhenHaveRecordWithSamePostIdAndActualIsTrue_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString(), isActual: true);
+        InsertPostToDatabaseAndReturn(post.Id, isActual: true);
+        Assert.That(() => _postStorageContract.AddElement(post), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString());
+        InsertPostToDatabaseAndReturn(post.Id, isActual: true);
+        _postStorageContract.UpdElement(post);
+        var posts = SquirrelDbContext.Posts.Where(x => x.PostId == post.Id).OrderByDescending(x => x.ChangeDate);
+        Assert.That(posts.Count(), Is.EqualTo(2));
+        AssertElement(posts.First(), CreateModel(post.Id, isActual: true));
+        AssertElement(posts.Last(), CreateModel(post.Id, isActual: false));
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenActualIsFalse_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString(), isActual: false);
+        InsertPostToDatabaseAndReturn(post.Id, isActual: true);
+        _postStorageContract.UpdElement(post);
+        AssertElement(GetPostFromDatabaseByPostId(post.Id), CreateModel(post.Id, isActual: true));
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _postStorageContract.UpdElement(CreateModel(Guid.NewGuid().ToString())), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenHaveRecordWithSameName_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString(), "New Name");
+        InsertPostToDatabaseAndReturn(post.Id, postName: "name");
+        InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), postName: post.PostName);
+        Assert.That(() => _postStorageContract.UpdElement(post), Throws.TypeOf<ElementExistsException>());
+    }
+
+    [Test]
+    public void Try_UpdElement_WhenRecordWasDeleted_Test()
+    {
+        var post = CreateModel(Guid.NewGuid().ToString());
+        InsertPostToDatabaseAndReturn(post.Id, isActual: false);
+        Assert.That(() => _postStorageContract.UpdElement(post), Throws.TypeOf<ElementDeletedException>());
+    }
+
+    [Test]
+    public void Try_DelElement_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), isActual: true);
+        _postStorageContract.DelElement(post.PostId);
+        var element = GetPostFromDatabaseByPostId(post.PostId);
+        Assert.Multiple(() =>
+        {
+            Assert.That(element, Is.Not.Null);
+            Assert.That(!element!.IsActual);
+        });
+    }
+
+    [Test]
+    public void Try_DelElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _postStorageContract.DelElement(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_DelElement_WhenRecordWasDeleted_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), isActual: false);
+        Assert.That(() => _postStorageContract.DelElement(post.PostId), Throws.TypeOf<ElementDeletedException>());
+    }
+
+    [Test]
+    public void Try_ResElement_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), isActual: false);
+        _postStorageContract.ResElement(post.PostId);
+        var element = GetPostFromDatabaseByPostId(post.PostId);
+        Assert.Multiple(() =>
+        {
+            Assert.That(element, Is.Not.Null);
+            Assert.That(element!.IsActual);
+        });
+    }
+
+    [Test]
+    public void Try_ResElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _postStorageContract.ResElement(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_ResElement_WhenRecordNotWasDeleted_Test()
+    {
+        var post = InsertPostToDatabaseAndReturn(Guid.NewGuid().ToString(), isActual: true);
+        Assert.That(() => _postStorageContract.ResElement(post.PostId), Throws.Nothing);
+    }
+
+    private Post InsertPostToDatabaseAndReturn(string id, string postName = "test", PostType postType = PostType.Manager, double salary = 10, bool isActual = true, DateTime? changeDate = null)
+    {
+        var post = new Post() { Id = Guid.NewGuid().ToString(), PostId = id, PostName = postName, PostType = postType, Salary = salary, IsActual = isActual, ChangeDate = changeDate ?? DateTime.UtcNow };
+        SquirrelDbContext.Posts.Add(post);
+        SquirrelDbContext.SaveChanges();
+        return post;
+    }
+
+    private static void AssertElement(PostDataModel? actual, Post expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.PostId));
+            Assert.That(actual.PostName, Is.EqualTo(expected.PostName));
+            Assert.That(actual.PostType, Is.EqualTo(expected.PostType));
+            Assert.That(actual.Salary, Is.EqualTo(expected.Salary));
+            Assert.That(actual.IsActual, Is.EqualTo(expected.IsActual));
+        });
+    }
+
+    private static PostDataModel CreateModel(string postId, string postName = "test", PostType postType = PostType.Manager, double salary = 10, bool isActual = false, DateTime? changeDate = null)
+        => new(postId, postName, postType, salary, isActual, changeDate ?? DateTime.UtcNow);
+
+    private Post? GetPostFromDatabaseByPostId(string id) => SquirrelDbContext.Posts.Where(x => x.PostId == id).OrderByDescending(x => x.ChangeDate).FirstOrDefault();
+
+    private static void AssertElement(Post? actual, PostDataModel expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.PostId, Is.EqualTo(expected.Id));
+            Assert.That(actual.PostName, Is.EqualTo(expected.PostName));
+            Assert.That(actual.PostType, Is.EqualTo(expected.PostType));
+            Assert.That(actual.Salary, Is.EqualTo(expected.Salary));
+            Assert.That(actual.IsActual, Is.EqualTo(expected.IsActual));
+        });
+    }
+}

SquirrelContract/SquirrelTests/StorageContracts/SalaryStorageContractTests.cs

@@ -0,0 +1,150 @@
+using BarBelochkaContract.DataModels;
+using Microsoft.EntityFrameworkCore;
+using SquirrelContract.StoragesContracts;
+using SquirrelDatabase.Implementations;
+using SquirrelDatabase.Models;
+using SquirrelTests.StoragesContracts;
+
+namespace SquirrelTests.StorageContracts;
+
+[TestFixture]
+internal class SalaryStorageContractTests : BaseStorageContractTest
+{
+    private SalaryStorageContract _salaryStorageContract;
+    private Employee _employee;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _salaryStorageContract = new SalaryStorageContract(SquirrelDbContext);
+        _employee = InsertEmployeeToDatabaseAndReturn();
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Salaries\" CASCADE;");
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Employees\" CASCADE;");
+    }
+
+    [Test]
+    public void Try_GetList_WhenHaveRecords_Test()
+    {
+        var salary = InsertSalaryToDatabaseAndReturn(_employee.Id, employeeSalary: 100);
+        InsertSalaryToDatabaseAndReturn(_employee.Id);
+        InsertSalaryToDatabaseAndReturn(_employee.Id);
+        var list = _salaryStorageContract.GetList(DateTime.UtcNow.AddDays(-10), DateTime.UtcNow.AddDays(10));
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+        AssertElement(list.First(), salary);
+    }
+
+    [Test]
+    public void Try_GetList_WhenNoRecords_Test()
+    {
+        var list = _salaryStorageContract.GetList(DateTime.UtcNow.AddDays(-10), DateTime.UtcNow.AddDays(10));
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.Empty);
+    }
+
+    [Test]
+    public void Try_GetList_OnlyInDatePeriod_Test()
+    {
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-2));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-1).AddMinutes(-5));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-1).AddMinutes(5));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(1).AddMinutes(-5));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(1).AddMinutes(5));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-2));
+        var list = _salaryStorageContract.GetList(DateTime.UtcNow.AddDays(-1), DateTime.UtcNow.AddDays(1));
+        Assert.That(list, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(list, Has.Count.EqualTo(2));
+        });
+    }
+
+    [Test]
+    public void Try_GetList_ByEmployee_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn("name 2");
+        InsertSalaryToDatabaseAndReturn(_employee.Id);
+        InsertSalaryToDatabaseAndReturn(_employee.Id);
+        InsertSalaryToDatabaseAndReturn(employee.Id);
+        var list = _salaryStorageContract.GetList(DateTime.UtcNow.AddDays(-1), DateTime.UtcNow.AddDays(1), _employee.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(list, Has.Count.EqualTo(2));
+            Assert.That(list.All(x => x.EmployeeId == _employee.Id));
+        });
+    }
+
+    [Test]
+    public void Try_GetList_ByEmployeeOnlyInDatePeriod_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn("name 2");
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-2));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-1).AddMinutes(5));
+        InsertSalaryToDatabaseAndReturn(employee.Id, salaryDate: DateTime.UtcNow.AddDays(-1).AddMinutes(5));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(1).AddMinutes(-5));
+        InsertSalaryToDatabaseAndReturn(employee.Id, salaryDate: DateTime.UtcNow.AddDays(1).AddMinutes(-5));
+        InsertSalaryToDatabaseAndReturn(_employee.Id, salaryDate: DateTime.UtcNow.AddDays(-2));
+        var list = _salaryStorageContract.GetList(DateTime.UtcNow.AddDays(-1), DateTime.UtcNow.AddDays(1), _employee.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(list, Has.Count.EqualTo(2));
+            Assert.That(list.All(x => x.EmployeeId == _employee.Id));
+        });
+    }
+
+    [Test]
+    public void Try_AddElement_Test()
+    {
+        var salary = CreateModel(_employee.Id);
+        _salaryStorageContract.AddElement(salary);
+        AssertElement(GetSalaryFromDatabaseByEmployeeId(_employee.Id), salary);
+    }
+
+    private Employee InsertEmployeeToDatabaseAndReturn(string employeeFIO = "fio", string employeeEmail = "abc@mail.ru")
+    {
+        var employee = new Employee() { Id = Guid.NewGuid().ToString(), PostId = Guid.NewGuid().ToString(), FIO = employeeFIO, Email = employeeEmail, IsDeleted = false };
+        SquirrelDbContext.Employees.Add(employee);
+        SquirrelDbContext.SaveChanges();
+        return employee;
+    }
+
+    private Salary InsertSalaryToDatabaseAndReturn(string employeeId, double employeeSalary = 1, DateTime? salaryDate = null)
+    {
+        var salary = new Salary() { EmployeeId = employeeId, EmployeeSalary = employeeSalary, SalaryDate = salaryDate ?? DateTime.UtcNow };
+        SquirrelDbContext.Salaries.Add(salary);
+        SquirrelDbContext.SaveChanges();
+        return salary;
+    }
+
+    private static void AssertElement(SalaryDataModel? actual, Salary expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.EmployeeId, Is.EqualTo(expected.EmployeeId));
+            Assert.That(actual.Salary, Is.EqualTo(expected.EmployeeSalary));
+        });
+    }
+
+    private static SalaryDataModel CreateModel(string employeeId, double employeeSalary = 1, DateTime? salaryDate = null)
+        => new(employeeId, salaryDate ?? DateTime.UtcNow, employeeSalary);
+
+    private Salary? GetSalaryFromDatabaseByEmployeeId(string id) => SquirrelDbContext.Salaries.FirstOrDefault(x => x.EmployeeId == id);
+
+    private static void AssertElement(Salary? actual, SalaryDataModel expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.EmployeeId, Is.EqualTo(expected.EmployeeId));
+            Assert.That(actual.EmployeeSalary, Is.EqualTo(expected.Salary));
+        });
+    }
+}

SquirrelContract/SquirrelTests/StorageContracts/SaleStorageContractTests.cs

@@ -0,0 +1,303 @@
+using SquirrelContract.DataModels;
+using SquirrelContract.Enums;
+using SquirrelContract.Exceptions;
+using SquirrelDatabase.Implementations;
+using SquirrelDatabase.Models;
+using static NUnit.Framework.Internal.OSPlatform;
+using System;
+using SquirrelTests.StoragesContracts;
+using Microsoft.EntityFrameworkCore;
+
+namespace SquirrelTests.StorageContracts;
+
+[TestFixture]
+internal class SaleStorageContractTests : BaseStorageContractTest
+{
+    private SaleStorageContract _saleStorageContract;
+    private Client _client;
+    private Employee _employee;
+    private Cocktail _cocktail;
+
+    [SetUp]
+    public void SetUp()
+    {
+        _saleStorageContract = new SaleStorageContract(SquirrelDbContext);
+        _client = InsertClientToDatabaseAndReturn();
+        _employee = InsertEmployeeToDatabaseAndReturn();
+        _cocktail = InsertCocktailToDatabaseAndReturn();
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Sales\" CASCADE;");
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Clients\" CASCADE;");
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Employees\" CASCADE;");
+        SquirrelDbContext.Database.ExecuteSqlRaw("TRUNCATE \"Cocktails\" CASCADE;");
+    }
+
+    [Test]
+    public void Try_GetList_WhenHaveRecords_Test()
+    {
+        var sale = InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 5)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, null, cocktails: [(_cocktail.Id, 10)]);
+        var list = _saleStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+        AssertElement(list.First(x => x.Id == sale.Id), sale);
+    }
+
+    [Test]
+    public void Try_GetList_WhenNoRecords_Test()
+    {
+        var list = _saleStorageContract.GetList();
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Is.Empty);
+    }
+
+    [Test]
+    public void Try_GetList_ByPeriod_Test()
+    {
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, saleDate: DateTime.UtcNow.AddDays(-1).AddMinutes(-3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, saleDate: DateTime.UtcNow.AddDays(-1).AddMinutes(3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, null, saleDate: DateTime.UtcNow.AddDays(1).AddMinutes(-3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, null, saleDate: DateTime.UtcNow.AddDays(1).AddMinutes(3), cocktails: [(_cocktail.Id, 1)]);
+        var list = _saleStorageContract.GetList(startDate: DateTime.UtcNow.AddDays(-1), endDate: DateTime.UtcNow.AddDays(1));
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+    }
+
+    [Test]
+    public void Try_GetList_ByEmployeeId_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn("Other employee");
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(employee.Id, null, cocktails: [(_cocktail.Id, 1)]);
+        var list = _saleStorageContract.GetList(employeeId: _employee.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+        Assert.That(list.All(x => x.EmployeeId == _employee.Id));
+    }
+
+    [Test]
+    public void Try_GetList_ByClientId_Test()
+    {
+        var client = InsertClientToDatabaseAndReturn("Other fio", "+8-888-888-88-88");
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, client.Id, cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, null, cocktails: [(_cocktail.Id, 1)]);
+        var list = _saleStorageContract.GetList(clientId: _client.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(2));
+        Assert.That(list.All(x => x.ClientId == _client.Id));
+    }
+
+    [Test]
+    public void Try_GetList_ByCocktailId_Test()
+    {
+        var cocktail = InsertCocktailToDatabaseAndReturn("Other name");
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 5)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1), (cocktail.Id, 4)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, null, cocktails: [(cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, null, cocktails: [(cocktail.Id, 1), (_cocktail.Id, 1)]);
+        var list = _saleStorageContract.GetList(cocktailId: _cocktail.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(3));
+        Assert.That(list.All(x => x.Cocktails.Any(y => y.CocktailId == _cocktail.Id)));
+    }
+
+    [Test]
+    public void Try_GetList_ByAllParameters_Test()
+    {
+        var employee = InsertEmployeeToDatabaseAndReturn("Other employee");
+        var client = InsertClientToDatabaseAndReturn("Other fio", "+8-888-888-88-88");
+        var cocktail = InsertCocktailToDatabaseAndReturn("Other name");
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, saleDate: DateTime.UtcNow.AddDays(-1).AddMinutes(-3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(employee.Id, null, saleDate: DateTime.UtcNow.AddDays(-1).AddMinutes(3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(employee.Id, _client.Id, saleDate: DateTime.UtcNow.AddDays(-1).AddMinutes(3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(employee.Id, _client.Id, saleDate: DateTime.UtcNow.AddDays(-1).AddMinutes(3), cocktails: [(cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, client.Id, saleDate: DateTime.UtcNow.AddDays(1).AddMinutes(-3), cocktails: [(_cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, saleDate: DateTime.UtcNow.AddDays(1).AddMinutes(-3), cocktails: [(cocktail.Id, 1)]);
+        InsertSaleToDatabaseAndReturn(employee.Id, null, saleDate: DateTime.UtcNow.AddDays(1).AddMinutes(-3), cocktails: [(_cocktail.Id, 1)]);
+        var list = _saleStorageContract.GetList(startDate: DateTime.UtcNow.AddDays(-1), endDate: DateTime.UtcNow.AddDays(1), employeeId: _employee.Id, clientId: _client.Id, cocktailId: cocktail.Id);
+        Assert.That(list, Is.Not.Null);
+        Assert.That(list, Has.Count.EqualTo(1));
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenHaveRecord_Test()
+    {
+        var sale = InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        AssertElement(_saleStorageContract.GetElementById(sale.Id), sale);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenNoRecord_Test()
+    {
+        InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)]);
+        Assert.That(() => _saleStorageContract.GetElementById(Guid.NewGuid().ToString()), Is.Null);
+    }
+
+    [Test]
+    public void Try_GetElementById_WhenRecordHasCanceled_Test()
+    {
+        var sale = InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)], isCancel: true);
+        AssertElement(_saleStorageContract.GetElementById(sale.Id), sale);
+    }
+
+    [Test]
+    public void Try_AddElement_Test()
+    {
+        var sale = CreateModel(Guid.NewGuid().ToString(), _employee.Id, _client.Id, 1, DiscountType.RegularCustomer, 1, false, [_cocktail.Id]);
+        _saleStorageContract.AddElement(sale);
+        AssertElement(GetSaleFromDatabaseById(sale.Id), sale);
+    }
+
+    [Test]
+    public void Try_AddElement_WhenIsDeletedIsTrue_Test()
+    {
+        var sale = CreateModel(Guid.NewGuid().ToString(), _employee.Id, _client.Id, 1, DiscountType.RegularCustomer, 1, true, [_cocktail.Id]);
+        Assert.That(() => _saleStorageContract.AddElement(sale), Throws.Nothing);
+        AssertElement(GetSaleFromDatabaseById(sale.Id), CreateModel(sale.Id, _employee.Id, _client.Id, 1, DiscountType.RegularCustomer, 1, false, [_cocktail.Id]));
+    }
+
+    [Test]
+    public void Try_DelElement_Test()
+    {
+        var sale = InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)], isCancel: false);
+        _saleStorageContract.DelElement(sale.Id);
+        var element = GetSaleFromDatabaseById(sale.Id);
+        Assert.Multiple(() =>
+        {
+            Assert.That(element, Is.Not.Null);
+            Assert.That(element!.IsCancel);
+        });
+    }
+
+    [Test]
+    public void Try_DelElement_WhenNoRecordWithThisId_Test()
+    {
+        Assert.That(() => _saleStorageContract.DelElement(Guid.NewGuid().ToString()), Throws.TypeOf<ElementNotFoundException>());
+    }
+
+    [Test]
+    public void Try_DelElement_WhenRecordWasCanceled_Test()
+    {
+        var sale = InsertSaleToDatabaseAndReturn(_employee.Id, _client.Id, cocktails: [(_cocktail.Id, 1)], isCancel: true);
+        Assert.That(() => _saleStorageContract.DelElement(sale.Id), Throws.TypeOf<ElementDeletedException>());
+    }
+
+    private Client InsertClientToDatabaseAndReturn(string fio = "test", string phoneNumber = "+7-777-777-77-77")
+    {
+        var client = new Client() { Id = Guid.NewGuid().ToString(), FIO = fio, PhoneNumber = phoneNumber, DiscountSize = 10 };
+        SquirrelDbContext.Clients.Add(client);
+        SquirrelDbContext.SaveChanges();
+        return client;
+    }
+
+    private Employee InsertEmployeeToDatabaseAndReturn(string fio = "test", string employeeEmail = "abc@gmail.com")
+    {
+        var employee = new Employee() { Id = Guid.NewGuid().ToString(), FIO = fio, Email = employeeEmail, PostId = Guid.NewGuid().ToString() };
+        SquirrelDbContext.Employees.Add(employee);
+        SquirrelDbContext.SaveChanges();
+        return employee;
+    }
+
+    private Cocktail InsertCocktailToDatabaseAndReturn(string cocktailName = "test", AlcoholType baseAlcohol = AlcoholType.Whiskey, double price = 1)
+    {
+        var cocktail = new Cocktail() { Id = Guid.NewGuid().ToString(), CocktailName = cocktailName, BaseAlcohol = baseAlcohol, Price = price };
+        SquirrelDbContext.Cocktails.Add(cocktail);
+        SquirrelDbContext.SaveChanges();
+        return cocktail;
+    }
+
+    private Sale InsertSaleToDatabaseAndReturn(string employeeId, string? clientId, DateTime? saleDate = null, double sum = 1, DiscountType discountType = DiscountType.OnSale, double discount = 0, bool isCancel = false, List<(string, int)>? cocktails = null)
+    {
+        var sale = new Sale() { EmployeeId = employeeId, ClientId = clientId, SaleDate = saleDate ?? DateTime.UtcNow, Sum = sum, DiscountType = discountType, Discount = discount, IsCancel = isCancel, SaleCocktails = [] };
+        if (cocktails is not null)
+        {
+            foreach (var elem in cocktails)
+            {
+                sale.SaleCocktails.Add(new SaleCocktail { CocktailId = elem.Item1, SaleId = sale.Id, Count = elem.Item2 });
+            }
+        }
+        SquirrelDbContext.Sales.Add(sale);
+        SquirrelDbContext.SaveChanges();
+        return sale;
+    }
+
+    private static void AssertElement(SaleDataModel? actual, Sale expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.Id));
+            Assert.That(actual.EmployeeId, Is.EqualTo(expected.EmployeeId));
+            Assert.That(actual.ClientId, Is.EqualTo(expected.ClientId));
+            Assert.That(actual.DiscountType, Is.EqualTo(expected.DiscountType));
+            Assert.That(actual.Discount, Is.EqualTo(expected.Discount));
+            Assert.That(actual.IsCancel, Is.EqualTo(expected.IsCancel));
+        });
+
+        if (expected.SaleCocktails is not null)
+        {
+            Assert.That(actual.Cocktails, Is.Not.Null);
+            Assert.That(actual.Cocktails, Has.Count.EqualTo(expected.SaleCocktails.Count));
+            for (int i = 0; i < actual.Cocktails.Count; ++i)
+            {
+                Assert.Multiple(() =>
+                {
+                    Assert.That(actual.Cocktails[i].CocktailId, Is.EqualTo(expected.SaleCocktails[i].CocktailId));
+                    Assert.That(actual.Cocktails[i].Count, Is.EqualTo(expected.SaleCocktails[i].Count));
+                });
+            }
+        }
+        else
+        {
+            Assert.That(actual.Cocktails, Is.Null);
+        }
+    }
+
+    private static SaleDataModel CreateModel(string id, string employeeId, string? clientId, double sum, DiscountType discountType, double discount, bool isCancel, List<string> cocktailIds)
+    {
+        var cocktails = cocktailIds.Select(x => new SaleCocktailDataModel(id, x, 1)).ToList();
+        return new(id, employeeId, clientId, sum, discountType, discount, isCancel, cocktails);
+    }
+
+    private Sale? GetSaleFromDatabaseById(string id) => SquirrelDbContext.Sales.Include(x => x.SaleCocktails).FirstOrDefault(x => x.Id == id);
+
+    private static void AssertElement(Sale? actual, SaleDataModel expected)
+    {
+        Assert.That(actual, Is.Not.Null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(actual.Id, Is.EqualTo(expected.Id));
+            Assert.That(actual.EmployeeId, Is.EqualTo(expected.EmployeeId));
+            Assert.That(actual.ClientId, Is.EqualTo(expected.ClientId));
+            Assert.That(actual.DiscountType, Is.EqualTo(expected.DiscountType));
+            Assert.That(actual.Discount, Is.EqualTo(expected.Discount));
+            Assert.That(actual.IsCancel, Is.EqualTo(expected.IsCancel));
+        });
+
+        if (expected.Cocktails is not null)
+        {
+            Assert.That(actual.SaleCocktails, Is.Not.Null);
+            Assert.That(actual.SaleCocktails, Has.Count.EqualTo(expected.Cocktails.Count));
+            for (int i = 0; i < actual.SaleCocktails.Count; ++i)
+            {
+                Assert.Multiple(() =>
+                {
+                    Assert.That(actual.SaleCocktails[i].CocktailId, Is.EqualTo(expected.Cocktails[i].CocktailId));
+                    Assert.That(actual.SaleCocktails[i].Count, Is.EqualTo(expected.Cocktails[i].Count));
+                });
+            }
+        }
+        else
+        {
+            Assert.That(actual.SaleCocktails, Is.Null);
+        }
+    }
+}