eslint/lib/rules/no-new-symbol.js

   1 /**
   2  * @fileoverview Rule to disallow use of the new operator with the `Symbol` object
   3  * @author Alberto Rodríguez
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Rule Definition
  10 //------------------------------------------------------------------------------
  11
  12 module.exports = {
  13     meta: {
  14         type: "problem",
  15
  16         docs: {
  17             description: "disallow `new` operators with the `Symbol` object",
  18             recommended: true,
  19             url: "https://eslint.org/docs/rules/no-new-symbol"
  20         },
  21
  22         schema: [],
  23
  24         messages: {
  25             noNewSymbol: "`Symbol` cannot be called as a constructor."
  26         }
  27     },
  28
  29     create(context) {
  30
  31         return {
  32             "Program:exit"() {
  33                 const globalScope = context.getScope();
  34                 const variable = globalScope.set.get("Symbol");
  35
  36                 if (variable && variable.defs.length === 0) {
  37                     variable.references.forEach(ref => {
  38                         const node = ref.identifier;
  39                         const parent = node.parent;
  40
  41                         if (parent && parent.type === "NewExpression" && parent.callee === node) {
  42                             context.report({
  43                                 node,
  44                                 messageId: "noNewSymbol"
  45                             });
  46                         }
  47                     });
  48                 }
  49             }
  50         };
  51
  52     }
  53 };