Support t.Parallel?

[zchee]

Hi, thanks for providing great package :)

BTW, I saw goleak internal source and found below switch...case:

goleak/options.go

Line 118 in 1874254

case "testing.RunTests", "testing.(*T).Run":

But, I used t.Parallel func on my project testing. So, goleak suggested:

found unexpected goroutines

Is it the expected behavior? Or, Should I adding goleak.IgnoreTopFunction("testing.(*T).Parallel") to defer goleak.VerifyNoLeaks(t)? (and, is it correct use case?)

[houqp]

Got hit by the same issue, is there any reason not to add t.Parallel to the whitelist?

[zchee]

/cc @prashantv

[prashantv]

I think adding testing.(*T).Parallel is reasonable for ignoring tests that are queued to be run later.

I don't think we can support goroutine verification in parallel tests though, since goleak verified all running goroutines, and in parallel tests, the end of a single test may still have many other goroutines running from other tests.

[zchee]

@prashantv Thanks for the polite answer. I totally agreed with your thought.
I wait for merge #25 pull request :D

[houqp]

I think that's reasonable and the behavior should probably be documented :)

In our cases, the tests we run in parallel don't create extra go routines at all, so goleak should still be able to handle it. That said, I think our use-case is probably a pretty restricted edge-case ;)

[bwplotka]

Is t.Parrallel() something reasonable as a feature request though?

It would be really nice to join forces to finally have solution to this: detection of leak go routines and parallel tests. (:

Related discussion: fortytw2/leaktest#4

[prashantv]

I don't think there is a good solution for detecting goroutine leaks from a test when using t.Parallel since it's intentionally running with other tests which will definitely have their own running goroutines, and we cannot identify which goroutines are started by which test.

However, there is a workaround: Use the TestMain integration in the package,

func TestMain(m *testing.M) {
	goleak.VerifyTestMain(m)
}

This will verify that there's no leaks after all tests are run.