Unfortunately our profession can be learned from books. Because of that it can lead to a lot of individuals who claim to have the same experience as you but can't really program worth shit. Those tests weed out the people who can't from the cans.
I was looking for a job when the company I last worked for went in to the dead pool. One company I applied to and went for an interview gave me a test to take to make sure I was who I claimed to be. I was incensed and argued that I had a proven track record and refused to take the test. It resulted in them passing on me.
A friend had suggested I prepare code samples on mini CD-Rs. The 200 MB ones that are easy to find and cheap. I handed it to the last person I interviewed with. I was warned that I may need to produce code and make some code on the spot but it never happened. The code sample was sufficient. I'll also add that I was the only person to hand the person I interviewed with a code sample. None of the others who interviewed for the same job did. It made me stand out.
So prepare some code samples for them to look over. And even if they still ask you to do a test, swallow your pride and take the damn test. Sometimes we forget that those who have the gold make the rules.
