JSTests/test262/test/built-ins/Array/property-cast-nan-infinity.js

// Copyright 2009 the Sputnik authors.  All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
info: |
    A property name P (in the form of a string value) is an array index
    if and only if ToString(ToUint32(P)) is equal to P and ToUint32(P) is not equal to 2^32 - 1
es5id: 15.4_A1.1_T2
description: Checking for number primitive
---*/

var x = [];

x[NaN] = 1;
assert.sameValue(x[0], undefined, 'The value of x[0] is expected to equal undefined');
assert.sameValue(x["NaN"], 1, 'The value of x["NaN"] is expected to be 1');

var y = [];
y[Number.POSITIVE_INFINITY] = 1;
assert.sameValue(y[0], undefined, 'The value of y[0] is expected to equal undefined');
assert.sameValue(y["Infinity"], 1, 'The value of y["Infinity"] is expected to be 1');

var z = [];
z[Number.NEGATIVE_INFINITY] = 1;
assert.sameValue(z[0], undefined, 'The value of z[0] is expected to equal undefined');
assert.sameValue(z["-Infinity"], 1, 'The value of z["-Infinity"] is expected to be 1');