139 lines
4.2 KiB
JavaScript
139 lines
4.2 KiB
JavaScript
/**
|
|
* @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: [
|
|
{
|
|
type: "object",
|
|
properties: {
|
|
capIsConstructor: {
|
|
type: "boolean",
|
|
default: true
|
|
}
|
|
},
|
|
additionalProperties: false
|
|
}
|
|
]
|
|
},
|
|
|
|
create(context) {
|
|
const options = context.options[0] || {};
|
|
const capIsConstructor = options.capIsConstructor !== false;
|
|
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,
|
|
{ capIsConstructor }
|
|
);
|
|
}
|
|
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'." });
|
|
}
|
|
}
|
|
};
|
|
}
|
|
};
|