Test to ensure correct behaviour of Object.keys On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS Object.keys({}) is [] PASS Object.keys({a:null}) is ['a'] PASS Object.keys({a:null, b:null}) is ['a', 'b'] PASS Object.keys({b:null, a:null}) is ['b', 'a'] PASS Object.keys([]) is [] PASS Object.keys([null]) is ['0'] PASS Object.keys([null,null]) is ['0','1'] PASS Object.keys([null,null,,,,null]) is ['0','1','5'] PASS Object.keys({__proto__:{a:null}}) is [] PASS Object.keys({__proto__:[1,2,3]}) is [] PASS x=[];x.__proto__=[1,2,3];Object.keys(x) is [] PASS successfullyParsed is true TEST COMPLETE