| /** |
| * @fileoverview Rule to flag when return statement contains assignment |
| * @author Ilya Volodin |
| */ |
| "use strict"; |
| |
| //------------------------------------------------------------------------------ |
| // Requirements |
| //------------------------------------------------------------------------------ |
| |
| const astUtils = require("./utils/ast-utils"); |
| |
| //------------------------------------------------------------------------------ |
| // Helpers |
| //------------------------------------------------------------------------------ |
| |
| const SENTINEL_TYPE = /^(?:[a-zA-Z]+?Statement|ArrowFunctionExpression|FunctionExpression|ClassExpression)$/u; |
| |
| //------------------------------------------------------------------------------ |
| // Rule Definition |
| //------------------------------------------------------------------------------ |
| |
| module.exports = { |
| meta: { |
| type: "suggestion", |
| |
| docs: { |
| description: "disallow assignment operators in `return` statements", |
| category: "Best Practices", |
| recommended: false, |
| url: "https://eslint.org/docs/rules/no-return-assign" |
| }, |
| |
| schema: [ |
| { |
| enum: ["except-parens", "always"] |
| } |
| ] |
| }, |
| |
| create(context) { |
| const always = (context.options[0] || "except-parens") !== "except-parens"; |
| const sourceCode = context.getSourceCode(); |
| |
| return { |
| AssignmentExpression(node) { |
| if (!always && astUtils.isParenthesised(sourceCode, node)) { |
| return; |
| } |
| |
| let currentChild = node; |
| let parent = currentChild.parent; |
| |
| // Find ReturnStatement or ArrowFunctionExpression in ancestors. |
| while (parent && !SENTINEL_TYPE.test(parent.type)) { |
| currentChild = parent; |
| parent = parent.parent; |
| } |
| |
| // Reports. |
| if (parent && parent.type === "ReturnStatement") { |
| context.report({ |
| node: parent, |
| message: "Return statement should not contain assignment." |
| }); |
| } else if (parent && parent.type === "ArrowFunctionExpression" && parent.body === currentChild) { |
| context.report({ |
| node: parent, |
| message: "Arrow function should not return assignment." |
| }); |
| } |
| } |
| }; |
| } |
| }; |