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             category: "ECMAScript 6",
  19             recommended: true,
  20             url: "https://eslint.org/docs/rules/no-new-symbol"
  21         },
  22
  23         schema: [],
  24
  25         messages: {
  26             noNewSymbol: "`Symbol` cannot be called as a constructor."
  27         }
  28     },
  29
  30     create(context) {
  31
  32         return {
  33             "Program:exit"() {
  34                 const globalScope = context.getScope();
  35                 const variable = globalScope.set.get("Symbol");
  36
  37                 if (variable && variable.defs.length === 0) {
  38                     variable.references.forEach(ref => {
  39                         const node = ref.identifier;
  40                         const parent = node.parent;
  41
  42                         if (parent && parent.type === "NewExpression" && parent.callee === node) {
  43                             context.report({
  44                                 node,
  45                                 messageId: "noNewSymbol"
  46                             });
  47                         }
  48                     });
  49                 }
  50             }
  51         };
  52
  53     }
  54 };