proxy-array-target-length-definition.js

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/*

 * Any copyright is dedicated to the Public Domain.

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

*/

var gTestfile = 'proxy-array-target-length-definition.js';

var BUGNUMBER = 905947;

var summary =

  "Redefining an array's |length| property when redefining the |length| " +

  "property on a proxy with an array as target";

print(BUGNUMBER + ": " + summary);

/**************

 * BEGIN TEST *

 **************/

var arr = [];

var p = new Proxy(arr, {});

function assertThrowsTypeError(f)

    try {

        f();

        assertEq(false, true, "Must have thrown");

    } catch (e) {

        assertEq(e instanceof TypeError, true, "Must have thrown TypeError");

// Redefining non-configurable length should throw a TypeError

assertThrowsTypeError(function () { Object.defineProperty(p, "length", { value: 17, configurable: true }); });

// Same here.

assertThrowsTypeError(function () { Object.defineProperty(p, "length", { value: 42, enumerable: true }); });

// Check the property went unchanged.

var pd = Object.getOwnPropertyDescriptor(p, "length");

assertEq(pd.value, 0);

assertEq(pd.writable, true);

assertEq(pd.enumerable, false);

assertEq(pd.configurable, false);

var ad = Object.getOwnPropertyDescriptor(arr, "length");

assertEq(ad.value, 0);

assertEq(ad.writable, true);

assertEq(ad.enumerable, false);

assertEq(ad.configurable, false);

/******************************************************************************/

if (typeof reportCompare === "function")

  reportCompare(true, true);

print("Tests complete");