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

   1 /**
   2  * @fileoverview A rule to disallow `this` keywords outside of classes or class-like objects.
   3  * @author Toru Nagashima
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Requirements
  10 //------------------------------------------------------------------------------
  11
  12 const astUtils = require("./utils/ast-utils");
  13
  14 //------------------------------------------------------------------------------
  15 // Rule Definition
  16 //------------------------------------------------------------------------------
  17
  18 module.exports = {
  19     meta: {
  20         type: "suggestion",
  21
  22         docs: {
  23             description: "disallow `this` keywords outside of classes or class-like objects",
  24             category: "Best Practices",
  25             recommended: false,
  26             url: "https://eslint.org/docs/rules/no-invalid-this"
  27         },
  28
  29         schema: [
  30             {
  31                 type: "object",
  32                 properties: {
  33                     capIsConstructor: {
  34                         type: "boolean",
  35                         default: true
  36                     }
  37                 },
  38                 additionalProperties: false
  39             }
  40         ]
  41     },
  42
  43     create(context) {
  44         const options = context.options[0] || {};
  45         const capIsConstructor = options.capIsConstructor !== false;
  46         const stack = [],
  47             sourceCode = context.getSourceCode();
  48
  49         /**
  50          * Gets the current checking context.
  51          *
  52          * The return value has a flag that whether or not `this` keyword is valid.
  53          * The flag is initialized when got at the first time.
  54          * @returns {{valid: boolean}}
  55          *   an object which has a flag that whether or not `this` keyword is valid.
  56          */
  57         stack.getCurrent = function() {
  58             const current = this[this.length - 1];
  59
  60             if (!current.init) {
  61                 current.init = true;
  62                 current.valid = !astUtils.isDefaultThisBinding(
  63                     current.node,
  64                     sourceCode,
  65                     { capIsConstructor }
  66                 );
  67             }
  68             return current;
  69         };
  70
  71         /**
  72          * Pushs new checking context into the stack.
  73          *
  74          * The checking context is not initialized yet.
  75          * Because most functions don't have `this` keyword.
  76          * When `this` keyword was found, the checking context is initialized.
  77          * @param {ASTNode} node A function node that was entered.
  78          * @returns {void}
  79          */
  80         function enterFunction(node) {
  81
  82             // `this` can be invalid only under strict mode.
  83             stack.push({
  84                 init: !context.getScope().isStrict,
  85                 node,
  86                 valid: true
  87             });
  88         }
  89
  90         /**
  91          * Pops the current checking context from the stack.
  92          * @returns {void}
  93          */
  94         function exitFunction() {
  95             stack.pop();
  96         }
  97
  98         return {
  99
 100             /*
 101              * `this` is invalid only under strict mode.
 102              * Modules is always strict mode.
 103              */
 104             Program(node) {
 105                 const scope = context.getScope(),
 106                     features = context.parserOptions.ecmaFeatures || {};
 107
 108                 stack.push({
 109                     init: true,
 110                     node,
 111                     valid: !(
 112                         scope.isStrict ||
 113                         node.sourceType === "module" ||
 114                         (features.globalReturn && scope.childScopes[0].isStrict)
 115                     )
 116                 });
 117             },
 118
 119             "Program:exit"() {
 120                 stack.pop();
 121             },
 122
 123             FunctionDeclaration: enterFunction,
 124             "FunctionDeclaration:exit": exitFunction,
 125             FunctionExpression: enterFunction,
 126             "FunctionExpression:exit": exitFunction,
 127
 128             // Reports if `this` of the current context is invalid.
 129             ThisExpression(node) {
 130                 const current = stack.getCurrent();
 131
 132                 if (current && !current.valid) {
 133                     context.report({ node, message: "Unexpected 'this'." });
 134                 }
 135             }
 136         };
 137     }
 138 };