This tests that a call to array.sort(compareFunction) works correctly for numeric comparisons (arg1 - arg2), and also for things that might look like numeric comparisons. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS [3,1,5,2,4].sort(doSort) is [1,2,3,4,5] PASS [3,1,5,2,4].sort(dontSort) is [3,1,5,2,4] PASS successfullyParsed is true TEST COMPLETE