Testing is the new compiling.

Static typing fan: Static typing allows earlier detection of programming mistakes.

Valid if the only kind of errors you’re worried about are type errors. If you think (and you should) that your code might contain other kind of errors, you should write unit tests and those will catch type errors anyway.

Dynamic typing fan: With dynamic languages you don’t waste time compiling.

Valid if you don’t test or check your code at all. Otherwise, you still have to waste time running tests and checkers.

Testing is my new perfect excuse for legitimately slacking off!

XKCD: Compiling