90 lines
2.8 KiB
JavaScript
90 lines
2.8 KiB
JavaScript
/**
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* @fileoverview A rule to warn against using arrow functions when they could be
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* confused with comparisons
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* @author Jxck <https://github.com/Jxck>
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*/
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"use strict";
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const astUtils = require("./utils/ast-utils.js");
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//------------------------------------------------------------------------------
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// Helpers
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//------------------------------------------------------------------------------
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/**
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* Checks whether or not a node is a conditional expression.
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* @param {ASTNode} node node to test
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* @returns {boolean} `true` if the node is a conditional expression.
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*/
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function isConditional(node) {
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return node && node.type === "ConditionalExpression";
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}
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//------------------------------------------------------------------------------
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// Rule Definition
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//------------------------------------------------------------------------------
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/** @type {import('../shared/types').Rule} */
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module.exports = {
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meta: {
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type: "suggestion",
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docs: {
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description: "Disallow arrow functions where they could be confused with comparisons",
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recommended: false,
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url: "https://eslint.org/docs/latest/rules/no-confusing-arrow"
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},
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fixable: "code",
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schema: [{
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type: "object",
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properties: {
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allowParens: { type: "boolean", default: true },
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onlyOneSimpleParam: { type: "boolean", default: false }
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},
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additionalProperties: false
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}],
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messages: {
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confusing: "Arrow function used ambiguously with a conditional expression."
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}
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},
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create(context) {
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const config = context.options[0] || {};
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const allowParens = config.allowParens || (config.allowParens === void 0);
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const onlyOneSimpleParam = config.onlyOneSimpleParam;
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const sourceCode = context.sourceCode;
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/**
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* Reports if an arrow function contains an ambiguous conditional.
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* @param {ASTNode} node A node to check and report.
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* @returns {void}
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*/
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function checkArrowFunc(node) {
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const body = node.body;
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if (isConditional(body) &&
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!(allowParens && astUtils.isParenthesised(sourceCode, body)) &&
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!(onlyOneSimpleParam && !(node.params.length === 1 && node.params[0].type === "Identifier"))) {
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context.report({
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node,
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messageId: "confusing",
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fix(fixer) {
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// if `allowParens` is not set to true don't bother wrapping in parens
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return allowParens && fixer.replaceText(node.body, `(${sourceCode.getText(node.body)})`);
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}
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});
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}
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}
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return {
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ArrowFunctionExpression: checkArrowFunc
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};
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}
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};
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