| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178 | /** * @fileoverview Rule to flag adding properties to native object's prototypes. * @author David Nelson */"use strict";//------------------------------------------------------------------------------// Requirements//------------------------------------------------------------------------------const astUtils = require("./utils/ast-utils");const globals = require("globals");//------------------------------------------------------------------------------// Rule Definition//------------------------------------------------------------------------------/** @type {import('../shared/types').Rule} */module.exports = {    meta: {        type: "suggestion",        docs: {            description: "Disallow extending native types",            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"            );        }        /**         * Check if it's an assignment to the property of the given node.         * Example: `*.prop = 0` // the `*` is the given node.         * @param {ASTNode} node The node to check.         * @returns {boolean} True if an assignment to the property of the node.         */        function isAssigningToPropertyOf(node) {            return (                node.parent.type === "MemberExpression" &&                node.parent.object === node &&                node.parent.parent.type === "AssignmentExpression" &&                node.parent.parent.left === node.parent            );        }        /**         * Checks if the given node is at the first argument of the method call of `Object.defineProperty()` or `Object.defineProperties()`.         * @param {ASTNode} node The node to check.         * @returns {boolean} True if the node is at the first argument of the method call of `Object.defineProperty()` or `Object.defineProperties()`.         */        function isInDefinePropertyCall(node) {            return (                node.parent.type === "CallExpression" &&                node.parent.arguments[0] === node &&                astUtils.isSpecificMemberAccess(node.parent.callee, "Object", /^definePropert(?:y|ies)$/u)            );        }        /**         * 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 (!isPrototypePropertyAccessed(identifierNode)) {                return; // This is not `*.prototype` access.            }            /*             * `identifierNode.parent` is a MemberExpression `*.prototype`.             * If it's an optional member access, it may be wrapped by a `ChainExpression` node.             */            const prototypeNode =                identifierNode.parent.parent.type === "ChainExpression"                    ? identifierNode.parent.parent                    : identifierNode.parent;            if (isAssigningToPropertyOf(prototypeNode)) {                // `*.prototype` -> MemberExpression -> AssignmentExpression                reportNode(prototypeNode.parent.parent, identifierNode.name);            } else if (isInDefinePropertyCall(prototypeNode)) {                // `*.prototype` -> CallExpression                reportNode(prototypeNode.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);                    }                });            }        };    }};
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