добавлние exception

MagicCarpetProject/MagicCarpetContracts/Exceptions/ElementExistsException.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MagicCarpetContracts.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;
+    }
+}

MagicCarpetProject/MagicCarpetContracts/Exceptions/ElementNotFoundException .cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MagicCarpetContracts.Exceptions;
+
+public class ElementNotFoundException : Exception
+{
+    public string Value { get; private set; }
+
+    public ElementNotFoundException(string value) : base($"Element not found at value = {value}")
+    {
+        Value = value;
+    }
+}

MagicCarpetProject/MagicCarpetContracts/Exceptions/IncorrectDatesException .cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MagicCarpetContracts.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}") { }
+}

MagicCarpetProject/MagicCarpetContracts/Exceptions/NullListException.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MagicCarpetContracts.Exceptions;
+
+public class NullListException : Exception
+{
+    public NullListException() : base("The returned list is null") { }
+}

MagicCarpetProject/MagicCarpetContracts/Exceptions/StorageException .cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MagicCarpetContracts.Exceptions;
+
+public class StorageException : Exception
+{
+    public StorageException(Exception ex) : base($"Error while working in storage: {ex.Message}", ex) { }
+}