.config/coc/extensions/node_modules/coc-prettier/node_modules/eslint/lib/rules/no-return-assign.js

   1 /**
   2  * @fileoverview Rule to flag when return statement contains assignment
   3  * @author Ilya Volodin
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const astUtils = require("./utils/ast-utils");
  12
  13 //------------------------------------------------------------------------------
  14 // Helpers
  15 //------------------------------------------------------------------------------
  16
  17 const SENTINEL_TYPE = /^(?:[a-zA-Z]+?Statement|ArrowFunctionExpression|FunctionExpression|ClassExpression)$/u;
  18
  19 //------------------------------------------------------------------------------
  20 // Rule Definition
  21 //------------------------------------------------------------------------------
  22
  23 module.exports = {
  24     meta: {
  25         type: "suggestion",
  26
  27         docs: {
  28             description: "disallow assignment operators in `return` statements",
  29             category: "Best Practices",
  30             recommended: false,
  31             url: "https://eslint.org/docs/rules/no-return-assign"
  32         },
  33
  34         schema: [
  35             {
  36                 enum: ["except-parens", "always"]
  37             }
  38         ]
  39     },
  40
  41     create(context) {
  42         const always = (context.options[0] || "except-parens") !== "except-parens";
  43         const sourceCode = context.getSourceCode();
  44
  45         return {
  46             AssignmentExpression(node) {
  47                 if (!always && astUtils.isParenthesised(sourceCode, node)) {
  48                     return;
  49                 }
  50
  51                 let currentChild = node;
  52                 let parent = currentChild.parent;
  53
  54                 // Find ReturnStatement or ArrowFunctionExpression in ancestors.
  55                 while (parent && !SENTINEL_TYPE.test(parent.type)) {
  56                     currentChild = parent;
  57                     parent = parent.parent;
  58                 }
  59
  60                 // Reports.
  61                 if (parent && parent.type === "ReturnStatement") {
  62                     context.report({
  63                         node: parent,
  64                         message: "Return statement should not contain assignment."
  65                     });
  66                 } else if (parent && parent.type === "ArrowFunctionExpression" && parent.body === currentChild) {
  67                     context.report({
  68                         node: parent,
  69                         message: "Arrow function should not return assignment."
  70                     });
  71                 }
  72             }
  73         };
  74     }
  75 };