src/third_party/mozjs-45/js/src/tests/test262/ch11/11.6/11.6.2/S11.6.2_A3_T1.4.js

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

/**
 * Operator x - y returns ToNumber(x) - ToNumber(y)
 *
 * @path ch11/11.6/11.6.2/S11.6.2_A3_T1.4.js
 * @description Type(x) and Type(y) vary between Null and Undefined
 */

//CHECK#1
if (isNaN(null - undefined) !== true) {
  $ERROR('#1: null - undefined === Not-a-Number. Actual: ' + (null - undefined));
}

//CHECK#2
if (isNaN(undefined - null) !== true) {
  $ERROR('#2: undefined - null === Not-a-Number. Actual: ' + (undefined - null));
}

//CHECK#3
if (isNaN(undefined - undefined) !== true) {
  $ERROR('#3: undefined - undefined === Not-a-Number. Actual: ' + (undefined - undefined));
}

//CHECK#4
if (null - null !== 0) {
  $ERROR('#4: null - null === 0. Actual: ' + (null - null));
}