Autotest is a great idea. When it worked for me, I loved it. But I hardly ever used it. Our complicated codebase choked on it - something to do with accounts as subdomains or double-loading of
test_helper when running the test suite or some such. Frankly, I don’t remember the details, but I do remember the multiple two-hour wild goose chases to try to get the lovely software to work for me. Unfortunately I wasn’t up to the task.