Test for error messages on function.apply On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS function foo(){}; foo.apply(null, 20) threw exception TypeError: second argument to Function.prototype.apply must be an Array-like object (evaluating 'foo.apply(null, 20)'). PASS function foo(){}; foo.apply(null, 'hello') threw exception TypeError: second argument to Function.prototype.apply must be an Array-like object (evaluating 'foo.apply(null, 'hello')'). PASS function foo(){}; foo.apply(null, true) threw exception TypeError: second argument to Function.prototype.apply must be an Array-like object (evaluating 'foo.apply(null, true)'). PASS successfullyParsed is true TEST COMPLETE