180 lines
		
	
	
		
			6.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			180 lines
		
	
	
		
			6.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
/**
 | 
						|
 * @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/latest/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 sourceCode = context.sourceCode;
 | 
						|
        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"(node) {
 | 
						|
                const globalScope = sourceCode.getScope(node);
 | 
						|
 | 
						|
                modifiedBuiltins.forEach(builtin => {
 | 
						|
                    const builtinVar = globalScope.set.get(builtin);
 | 
						|
 | 
						|
                    if (builtinVar && builtinVar.references) {
 | 
						|
                        builtinVar.references
 | 
						|
                            .map(ref => ref.identifier)
 | 
						|
                            .forEach(checkAndReportPrototypeExtension);
 | 
						|
                    }
 | 
						|
                });
 | 
						|
            }
 | 
						|
        };
 | 
						|
 | 
						|
    }
 | 
						|
};
 |