> thought I checked for that but apparently I got confused. I do find it > disconcerting that the random seed can get incremented by > LuceneTestCase.newDirectory() a different number of times depending on > wether or not -Dtests.seed has been set.
It's not really like that. By passing -Dtests.seed you're not "just" incrementing/ changing the random generator. You're starting from a different seed so you're running a whole different execution scenario. Think of it as Heisenberg's uncertainty principle -- if you've touched something on the lab plate (anything) then the outcome will be different. If you want your test to pick a random directory but make this choice insensitive to tests.seed then use the newDirectory(Random) method with a "forked" random number generator. As in here: Random forkedRandom = new Random(random().nextLong()); Directory myDirectory = LuceneTestCase.newDirectory(forkedRandom); then you can change "myDirectory" to your liking and it won't affect the default random generator... Random forkedRandom = new Random(random().nextLong()); // you don't even need to call newDirectory(forkedRandom) but I'll keep it here. Directory myDirectory = LuceneTestCase.newDirectory(forkedRandom); // temporarily substitute with something else... myDirectory = ...; > test that uses randomization to "just" change the directory for a given test > run (i.e. for a given seed). It would be nice if there was a mechanism to > restore the random state so you could restore it from when it was captured > at the beginning of a method call. This wouldn't just apply to > newDirectory() but to some other similar utility methods. I'm sorry but I don't see the advantage of that. You're trying to do something for which better alternatives exist, as explained above. If your code wants to make certain branch/ logic independent of the default randomness you can just use your own Random instance (seeded with a constant or whatever else that comes to your mind or is helpful in the context). Dawid --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
