Permalink
Cannot retrieve contributors at this time
| /** | |
| * @fileoverview A rule to disallow `this` keywords outside of classes or class-like objects. | |
| * @author Toru Nagashima | |
| */ | |
| "use strict"; | |
| //------------------------------------------------------------------------------ | |
| // Requirements | |
| //------------------------------------------------------------------------------ | |
| const astUtils = require("./utils/ast-utils"); | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
| module.exports = { | |
| meta: { | |
| type: "suggestion", | |
| docs: { | |
| description: "disallow `this` keywords outside of classes or class-like objects", | |
| category: "Best Practices", | |
| recommended: false, | |
| url: "https://eslint.org/docs/rules/no-invalid-this" | |
| }, | |
| schema: [] | |
| }, | |
| create(context) { | |
| const stack = [], | |
| sourceCode = context.getSourceCode(); | |
| /** | |
| * Gets the current checking context. | |
| * | |
| * The return value has a flag that whether or not `this` keyword is valid. | |
| * The flag is initialized when got at the first time. | |
| * @returns {{valid: boolean}} | |
| * an object which has a flag that whether or not `this` keyword is valid. | |
| */ | |
| stack.getCurrent = function() { | |
| const current = this[this.length - 1]; | |
| if (!current.init) { | |
| current.init = true; | |
| current.valid = !astUtils.isDefaultThisBinding( | |
| current.node, | |
| sourceCode | |
| ); | |
| } | |
| return current; | |
| }; | |
| /** | |
| * Pushs new checking context into the stack. | |
| * | |
| * The checking context is not initialized yet. | |
| * Because most functions don't have `this` keyword. | |
| * When `this` keyword was found, the checking context is initialized. | |
| * @param {ASTNode} node A function node that was entered. | |
| * @returns {void} | |
| */ | |
| function enterFunction(node) { | |
| // `this` can be invalid only under strict mode. | |
| stack.push({ | |
| init: !context.getScope().isStrict, | |
| node, | |
| valid: true | |
| }); | |
| } | |
| /** | |
| * Pops the current checking context from the stack. | |
| * @returns {void} | |
| */ | |
| function exitFunction() { | |
| stack.pop(); | |
| } | |
| return { | |
| /* | |
| * `this` is invalid only under strict mode. | |
| * Modules is always strict mode. | |
| */ | |
| Program(node) { | |
| const scope = context.getScope(), | |
| features = context.parserOptions.ecmaFeatures || {}; | |
| stack.push({ | |
| init: true, | |
| node, | |
| valid: !( | |
| scope.isStrict || | |
| node.sourceType === "module" || | |
| (features.globalReturn && scope.childScopes[0].isStrict) | |
| ) | |
| }); | |
| }, | |
| "Program:exit"() { | |
| stack.pop(); | |
| }, | |
| FunctionDeclaration: enterFunction, | |
| "FunctionDeclaration:exit": exitFunction, | |
| FunctionExpression: enterFunction, | |
| "FunctionExpression:exit": exitFunction, | |
| // Reports if `this` of the current context is invalid. | |
| ThisExpression(node) { | |
| const current = stack.getCurrent(); | |
| if (current && !current.valid) { | |
| context.report({ node, message: "Unexpected 'this'." }); | |
| } | |
| } | |
| }; | |
| } | |
| }; |