ownKeys.js - mozsearch

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/* Any copyright is dedicated to the Public Domain.

 * http://creativecommons.org/licenses/publicdomain/ */

// Reflect.ownKeys(obj) returns an array of an object's own property keys.

// Test that Reflect.ownKeys gets the expected result when applied to various

// objects. (These tests also check the basics: that the result is an array,

// that its prototype is correct, etc.)

var sym = Symbol.for("comet");

var sym2 = Symbol.for("meteor");

var cases = [

    {object: {z: 3, y: 2, x: 1},

     keys: ["z", "y", "x"]},

    {object: [],

     keys: ["length"]},

    {object: new Int8Array(4),

     keys: ["0", "1", "2", "3"]},

    {object: new Proxy({a: 7}, {}),

     keys: ["a"]},

    {object: {[sym]: "ok"},

     keys: [sym]},

    {object: {[sym]: 0,  // test 9.1.12 ordering

              "str": 0,

              "773": 0,

              "0": 0,

              [sym2]: 0,

              "-1": 0,

              "8": 0,

              "second str": 0},

     keys: ["0", "8", "773",  // indexes in numeric order

            "str", "-1", "second str", // strings in insertion order

            sym, sym2]}, // symbols in insertion order

    {object: newGlobal().Math,  // cross-compartment wrapper

     keys: Reflect.ownKeys(Math)}

];

for (var {object, keys} of cases)

    assertDeepEq(Reflect.ownKeys(object), keys);

// Reflect.ownKeys() creates a new array each time it is called.

var object = {}, keys = [];

for (var i = 0; i < 3; i++) {

    var newKeys = Reflect.ownKeys(object);

    assertEq(newKeys !== keys, true);

    keys = newKeys;

// Proxy behavior with successful ownKeys() handler

keys = ["str", "0"];

obj = {};

proxy = new Proxy(obj, {

    ownKeys() { return keys; }

});

var actual = Reflect.ownKeys(proxy);

assertDeepEq(actual, keys);  // we get correct answers

assertEq(actual !== keys, true);  // but not the same object

// If a proxy breaks invariants, a TypeError is thrown.

var obj = Object.preventExtensions({});

var proxy = new Proxy(obj, {

    ownKeys() { return ["something"]; }

});

assertThrowsInstanceOf(() => Reflect.ownKeys(proxy), TypeError);

// For more Reflect.ownKeys tests, see target.js.

reportCompare(0, 0);