Some tests simply cannot be deterministic because the underlying system is not deterministic (eg testing something that has multiple threads, perhaps some of wh

Some tests simply cannot be deterministic because the underlying system is not deterministic (eg testing something that has multiple threads, perhaps some of which live in far-flung members of members, etc). A dirty database is what I would call “avoidable non determinism” because you can easily clean it and you probably do not want to test handling bad databases (maybe you do though). Thread scheduling is not something you would want to work around, because you want to test a wide variety of actual production scheduling patterns to make sure there is not something like a deadlock (which also means, to get full value from the test, you probably need to run it hundreds of times and/or turn on sanitizers). One perhaps better word you are looking for re determinism is hermeticism. A dirty database with junk from previous runs makes the test non-hermetic (not self contained). You can have a hermetic but non-deterministic test also, like telling a bunch of threads to print the ABC’s.