Test to ensure correct behavior of Object.is On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS Object.is.length is 2 PASS Object.is.name is 'is' PASS Object.is(NaN, NaN) is true PASS Object.is(null, null) is true PASS Object.is(null) is false PASS Object.is(undefined, undefined) is true PASS Object.is(true, true) is true PASS Object.is(false, false) is true PASS Object.is('abc', 'abc') is true PASS Object.is(Infinity, Infinity) is true PASS Object.is(0, 0) is true PASS Object.is(-0, -0) is true PASS Object.is(0, -0) is false PASS Object.is(-0, 0) is false PASS var obj = {}; Object.is(obj, obj) is true PASS var arr = []; Object.is(arr, arr) is true PASS var sym = Symbol(); Object.is(sym, sym) is true PASS successfullyParsed is true TEST COMPLETE