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

   1 /**
   2  * @fileoverview Rule to flag references to the undefined variable.
   3  * @author Michael Ficarra
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Rule Definition
   9 //------------------------------------------------------------------------------
  10
  11 module.exports = {
  12     meta: {
  13         type: "suggestion",
  14
  15         docs: {
  16             description: "disallow the use of `undefined` as an identifier",
  17             category: "Variables",
  18             recommended: false,
  19             url: "https://eslint.org/docs/rules/no-undefined"
  20         },
  21
  22         schema: []
  23     },
  24
  25     create(context) {
  26
  27         /**
  28          * Report an invalid "undefined" identifier node.
  29          * @param {ASTNode} node The node to report.
  30          * @returns {void}
  31          */
  32         function report(node) {
  33             context.report({
  34                 node,
  35                 message: "Unexpected use of undefined."
  36             });
  37         }
  38
  39         /**
  40          * Checks the given scope for references to `undefined` and reports
  41          * all references found.
  42          * @param {eslint-scope.Scope} scope The scope to check.
  43          * @returns {void}
  44          */
  45         function checkScope(scope) {
  46             const undefinedVar = scope.set.get("undefined");
  47
  48             if (!undefinedVar) {
  49                 return;
  50             }
  51
  52             const references = undefinedVar.references;
  53
  54             const defs = undefinedVar.defs;
  55
  56             // Report non-initializing references (those are covered in defs below)
  57             references
  58                 .filter(ref => !ref.init)
  59                 .forEach(ref => report(ref.identifier));
  60
  61             defs.forEach(def => report(def.name));
  62         }
  63
  64         return {
  65             "Program:exit"() {
  66                 const globalScope = context.getScope();
  67
  68                 const stack = [globalScope];
  69
  70                 while (stack.length) {
  71                     const scope = stack.pop();
  72
  73                     stack.push(...scope.childScopes);
  74                     checkScope(scope);
  75                 }
  76             }
  77         };
  78
  79     }
  80 };