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Diffstat (limited to 'tools/node_modules/eslint/lib/rules/no-invalid-this.js')
-rw-r--r-- | tools/node_modules/eslint/lib/rules/no-invalid-this.js | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-invalid-this.js b/tools/node_modules/eslint/lib/rules/no-invalid-this.js new file mode 100644 index 0000000000..5a0a62f7a1 --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/no-invalid-this.js @@ -0,0 +1,123 @@ +/** + * @fileoverview A rule to disallow `this` keywords outside of classes or class-like objects. + * @author Toru Nagashima + */ + +"use strict"; + +//------------------------------------------------------------------------------ +// Requirements +//------------------------------------------------------------------------------ + +const astUtils = require("../ast-utils"); + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "disallow `this` keywords outside of classes or class-like objects", + category: "Best Practices", + recommended: false + }, + + 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'." }); + } + } + }; + } +}; |