You're correct. The other comments bring up tail recursion, which would deal with this issue, but they conveniently leave out the fact that almost no JavaScript runtime actually supports it.

I'm in shock :0

While you are right, the "stack problem" can be dealt by adding an accumulator: GetSumHelper(a, b, acc)

For more info: http://stackoverflow.com/questions/33923/what-is-tail-recursion#37010

While undoubtedly clever, I don't get why this has votes for best practice. As a and b get farther apart, the stack gets unnecessarily large.

Love it!

this is cool!!!

Very good hint! Thanks!

Omg this is cool

this is great, wish i had thought of it

You have to call it like

Test.expectError(function () {
  somefn(baddata); 
});

rather than

Test.expectError(someFn(baddata));

The documentation is a bit unclear

a test case is using expectError and I'm throwing an error and it shows on the output that I have thrown an error but the test case is still not regarded as a success. Am I doing something wrong? Shouldn't I throw an error?