180 lines
6.9 KiB
JavaScript
180 lines
6.9 KiB
JavaScript
/**
|
|
* @fileoverview Rule to flag adding properties to native object's prototypes.
|
|
* @author David Nelson
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Requirements
|
|
//------------------------------------------------------------------------------
|
|
|
|
const astUtils = require("../ast-utils");
|
|
const globals = require("globals");
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Helpers
|
|
//------------------------------------------------------------------------------
|
|
|
|
const propertyDefinitionMethods = new Set(["defineProperty", "defineProperties"]);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
docs: {
|
|
description: "disallow extending native types",
|
|
category: "Best Practices",
|
|
recommended: false,
|
|
url: "https://eslint.org/docs/rules/no-extend-native"
|
|
},
|
|
|
|
schema: [
|
|
{
|
|
type: "object",
|
|
properties: {
|
|
exceptions: {
|
|
type: "array",
|
|
items: {
|
|
type: "string"
|
|
},
|
|
uniqueItems: true
|
|
}
|
|
},
|
|
additionalProperties: false
|
|
}
|
|
],
|
|
|
|
messages: {
|
|
unexpected: "{{builtin}} prototype is read only, properties should not be added."
|
|
}
|
|
},
|
|
|
|
create(context) {
|
|
|
|
const config = context.options[0] || {};
|
|
const exceptions = new Set(config.exceptions || []);
|
|
const modifiedBuiltins = new Set(
|
|
Object.keys(globals.builtin)
|
|
.filter(builtin => builtin[0].toUpperCase() === builtin[0])
|
|
.filter(builtin => !exceptions.has(builtin))
|
|
);
|
|
|
|
/**
|
|
* Reports a lint error for the given node.
|
|
* @param {ASTNode} node The node to report.
|
|
* @param {string} builtin The name of the native builtin being extended.
|
|
* @returns {void}
|
|
*/
|
|
function reportNode(node, builtin) {
|
|
context.report({
|
|
node,
|
|
messageId: "unexpected",
|
|
data: {
|
|
builtin
|
|
}
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Check to see if the `prototype` property of the given object
|
|
* identifier node is being accessed.
|
|
* @param {ASTNode} identifierNode The Identifier representing the object
|
|
* to check.
|
|
* @returns {boolean} True if the identifier is the object of a
|
|
* MemberExpression and its `prototype` property is being accessed,
|
|
* false otherwise.
|
|
*/
|
|
function isPrototypePropertyAccessed(identifierNode) {
|
|
return Boolean(
|
|
identifierNode &&
|
|
identifierNode.parent &&
|
|
identifierNode.parent.type === "MemberExpression" &&
|
|
identifierNode.parent.object === identifierNode &&
|
|
astUtils.getStaticPropertyName(identifierNode.parent) === "prototype"
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Checks that an identifier is an object of a prototype whose member
|
|
* is being assigned in an AssignmentExpression.
|
|
* Example: Object.prototype.foo = "bar"
|
|
* @param {ASTNode} identifierNode The identifier to check.
|
|
* @returns {boolean} True if the identifier's prototype is modified.
|
|
*/
|
|
function isInPrototypePropertyAssignment(identifierNode) {
|
|
return Boolean(
|
|
isPrototypePropertyAccessed(identifierNode) &&
|
|
identifierNode.parent.parent.type === "MemberExpression" &&
|
|
identifierNode.parent.parent.parent.type === "AssignmentExpression" &&
|
|
identifierNode.parent.parent.parent.left === identifierNode.parent.parent
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Checks that an identifier is an object of a prototype whose member
|
|
* is being extended via the Object.defineProperty() or
|
|
* Object.defineProperties() methods.
|
|
* Example: Object.defineProperty(Array.prototype, "foo", ...)
|
|
* Example: Object.defineProperties(Array.prototype, ...)
|
|
* @param {ASTNode} identifierNode The identifier to check.
|
|
* @returns {boolean} True if the identifier's prototype is modified.
|
|
*/
|
|
function isInDefinePropertyCall(identifierNode) {
|
|
return Boolean(
|
|
isPrototypePropertyAccessed(identifierNode) &&
|
|
identifierNode.parent.parent.type === "CallExpression" &&
|
|
identifierNode.parent.parent.arguments[0] === identifierNode.parent &&
|
|
identifierNode.parent.parent.callee.type === "MemberExpression" &&
|
|
identifierNode.parent.parent.callee.object.type === "Identifier" &&
|
|
identifierNode.parent.parent.callee.object.name === "Object" &&
|
|
identifierNode.parent.parent.callee.property.type === "Identifier" &&
|
|
propertyDefinitionMethods.has(identifierNode.parent.parent.callee.property.name)
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Check to see if object prototype access is part of a prototype
|
|
* extension. There are three ways a prototype can be extended:
|
|
* 1. Assignment to prototype property (Object.prototype.foo = 1)
|
|
* 2. Object.defineProperty()/Object.defineProperties() on a prototype
|
|
* If prototype extension is detected, report the AssignmentExpression
|
|
* or CallExpression node.
|
|
* @param {ASTNode} identifierNode The Identifier representing the object
|
|
* which prototype is being accessed and possibly extended.
|
|
* @returns {void}
|
|
*/
|
|
function checkAndReportPrototypeExtension(identifierNode) {
|
|
if (isInPrototypePropertyAssignment(identifierNode)) {
|
|
|
|
// Identifier --> MemberExpression --> MemberExpression --> AssignmentExpression
|
|
reportNode(identifierNode.parent.parent.parent, identifierNode.name);
|
|
} else if (isInDefinePropertyCall(identifierNode)) {
|
|
|
|
// Identifier --> MemberExpression --> CallExpression
|
|
reportNode(identifierNode.parent.parent, identifierNode.name);
|
|
}
|
|
}
|
|
|
|
return {
|
|
|
|
"Program:exit"() {
|
|
const globalScope = context.getScope();
|
|
|
|
modifiedBuiltins.forEach(builtin => {
|
|
const builtinVar = globalScope.set.get(builtin);
|
|
|
|
if (builtinVar && builtinVar.references) {
|
|
builtinVar.references
|
|
.map(ref => ref.identifier)
|
|
.forEach(checkAndReportPrototypeExtension);
|
|
}
|
|
});
|
|
}
|
|
};
|
|
|
|
}
|
|
};
|