Chatting to a friend recently, we were discussing approaches to tests. I have always put the first test at the top of the .t file, the second test I write second and so on. But it occurred to me that this might not be ideal. Searching, I find that Test::Most has a die_on_fail setting, so my thinking is that if I were to put this option in and then write each new test at the top of the .t file, this might speed up TDD. The effect would be that writing a failing test would not result in all the passing tests having to run first, which is what happens now. The (previously) passing tests would be run only when the new (previously failing) test passed. The time gain would not be massive, but a few seconds over hundreds of iterations could well add up.
I haven't seen this documented anywhere. Is it a fascinating new insight (I don't think so), something that should have occurred to me much earlier or something so trivial that the gains aren't worth losing the train of thought that having tests in the right order exposes?