no-extend-native.js

/**
 * @fileoverview Tests for no-extend-native rule.
 * @author David Nelson
 */

"use strict";

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const rule = require("../../../lib/rules/no-extend-native"),
    { RuleTester } = require("../../../lib/rule-tester");

//------------------------------------------------------------------------------
// Tests
//------------------------------------------------------------------------------

const ruleTester = new RuleTester();

ruleTester.run("no-extend-native", rule, {
    valid: [
        "x.prototype.p = 0",
        "x.prototype['p'] = 0",
        "Object.p = 0",
        "Object.toString.bind = 0",
        "Object['toString'].bind = 0",
        "Object.defineProperty(x, 'p', {value: 0})",
        "Object.defineProperties(x, {p: {value: 0}})",
        "global.Object.prototype.toString = 0",
        "this.Object.prototype.toString = 0",
        "with(Object) { prototype.p = 0; }",
        "o = Object; o.prototype.toString = 0",
        "eval('Object.prototype.toString = 0')",
        "parseFloat.prototype.x = 1",
        {
            code: "Object.prototype.g = 0",
            options: [{ exceptions: ["Object"] }]
        },
        "obj[Object.prototype] = 0",

        // https://github.com/eslint/eslint/issues/4438
        "Object.defineProperty()",
        "Object.defineProperties()",

        // https://github.com/eslint/eslint/issues/8461
        "function foo() { var Object = function() {}; Object.prototype.p = 0 }",
        {
            code: "{ let Object = function() {}; Object.prototype.p = 0 }",
            parserOptions: { ecmaVersion: 6 }
        },

        // TODO(mdjermanovic): This test should become `invalid` in the next major version, when we upgrade the `globals` package.
        {
            code: "WeakRef.prototype.p = 0",
            env: { es2021: true }
        }
    ],
    invalid: [{
        code: "Object.prototype.p = 0",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Object" },
            type: "AssignmentExpression"
        }]
    }, {
        code: "BigInt.prototype.p = 0",
        env: { es2020: true },
        errors: [{
            messageId: "unexpected",
            data: { builtin: "BigInt" },
            type: "AssignmentExpression"
        }]
    }, {
        code: "Function.prototype['p'] = 0",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Function" },
            type: "AssignmentExpression"
        }]
    }, {
        code: "String['prototype'].p = 0",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "String" },
            type: "AssignmentExpression"
        }]
    }, {
        code: "Number['prototype']['p'] = 0",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Number" },
            type: "AssignmentExpression"
        }]
    }, {
        code: "Object.defineProperty(Array.prototype, 'p', {value: 0})",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Array" },
            type: "CallExpression"
        }]
    }, {
        code: "Object.defineProperties(Array.prototype, {p: {value: 0}})",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Array" },
            type: "CallExpression"
        }]
    }, {
        code: "Object.defineProperties(Array.prototype, {p: {value: 0}, q: {value: 0}})",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Array" },
            type: "CallExpression"
        }]
    },
    {
        code: "Number['prototype']['p'] = 0",
        options: [{ exceptions: ["Object"] }],
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Number" },
            type: "AssignmentExpression"
        }]
    },
    {
        code: "Object.prototype.p = 0; Object.prototype.q = 0",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Object" },
            type: "AssignmentExpression",
            column: 1
        }, {
            messageId: "unexpected",
            data: { builtin: "Object" },
            type: "AssignmentExpression",
            column: 25
        }]
    },
    {
        code: "function foo() { Object.prototype.p = 0 }",
        errors: [{
            messageId: "unexpected",
            data: { builtin: "Object" },
            type: "AssignmentExpression"
        }]
    },

    // Optional chaining
    {
        code: "(Object?.prototype).p = 0",
        parserOptions: { ecmaVersion: 2020 },
        errors: [{ messageId: "unexpected", data: { builtin: "Object" } }]
    },
    {
        code: "Object.defineProperty(Object?.prototype, 'p', { value: 0 })",
        parserOptions: { ecmaVersion: 2020 },
        errors: [{ messageId: "unexpected", data: { builtin: "Object" } }]
    },
    {
        code: "Object?.defineProperty(Object.prototype, 'p', { value: 0 })",
        parserOptions: { ecmaVersion: 2020 },
        errors: [{ messageId: "unexpected", data: { builtin: "Object" } }]
    },
    {
        code: "(Object?.defineProperty)(Object.prototype, 'p', { value: 0 })",
        parserOptions: { ecmaVersion: 2020 },
        errors: [{ messageId: "unexpected", data: { builtin: "Object" } }]
    }

    ]
});