.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         messages: {
  25             unexpectedUndefined: "Unexpected use of undefined."
  26         }
  27     },
  28
  29     create(context) {
  30
  31         /**
  32          * Report an invalid "undefined" identifier node.
  33          * @param {ASTNode} node The node to report.
  34          * @returns {void}
  35          */
  36         function report(node) {
  37             context.report({
  38                 node,
  39                 messageId: "unexpectedUndefined"
  40             });
  41         }
  42
  43         /**
  44          * Checks the given scope for references to `undefined` and reports
  45          * all references found.
  46          * @param {eslint-scope.Scope} scope The scope to check.
  47          * @returns {void}
  48          */
  49         function checkScope(scope) {
  50             const undefinedVar = scope.set.get("undefined");
  51
  52             if (!undefinedVar) {
  53                 return;
  54             }
  55
  56             const references = undefinedVar.references;
  57
  58             const defs = undefinedVar.defs;
  59
  60             // Report non-initializing references (those are covered in defs below)
  61             references
  62                 .filter(ref => !ref.init)
  63                 .forEach(ref => report(ref.identifier));
  64
  65             defs.forEach(def => report(def.name));
  66         }
  67
  68         return {
  69             "Program:exit"() {
  70                 const globalScope = context.getScope();
  71
  72                 const stack = [globalScope];
  73
  74                 while (stack.length) {
  75                     const scope = stack.pop();
  76
  77                     stack.push(...scope.childScopes);
  78                     checkScope(scope);
  79                 }
  80             }
  81         };
  82
  83     }
  84 };