How do you test periodic jobs?

[riking]

How do you properly test the behavior in a periodic job?

Let’s take some of my real code as an example:

func authorizationJanitor() {
	for {
		time.Sleep(5 * time.Minute)
		
		cullTime := time.Now().Add(-30 * time.Minute)

		PendingAuthLock.Lock()

		newPendingAuths := make([]PendingAuthorization, 0, len(PendingAuths))

		for _, v := range PendingAuths {
			if !cullTime.After(v.EnteredAt) {
				newPendingAuths = append(newPendingAuths, v)
			}
		}

		PendingAuths = newPendingAuths
		PendingAuthLock.Unlock()
	}
}

Okay, I can see what this is supposed to do. It’s a pretty small routine, not too hard to figure out.

But… how do I test it?
If I start the routine during the test, it’ll be trapped in the Sleep at the top for 5 minutes.

[Bjoern (Björn Graf)]

Of the top of my head it seems to be best to extract the time methods into an interface and ignore the sleep arguments in the test implementation.

[riking]

Wait, wouldn’t that just make it spin in the method?

Better would be to be able to trigger one on-demand from the testing function.

[riking]

Actually, I think I found something that works just fine:

func authorizationJanitor() {
	for {
		time.Sleep(5 * time.Minute)
		authorizationJanitor_do()
	}
}

func authorizationJanitor_do() {
	cullTime := time.Now().Add(-30 * time.Minute)

	PendingAuthLock.Lock()
	defer PendingAuthLock.Unlock()

	newPendingAuths := make([]PendingAuthorization, 0, len(PendingAuths))

	for _, v := range PendingAuths {
		if !cullTime.After(v.EnteredAt) {
			newPendingAuths = append(newPendingAuths, v)
		} else {
			v.Callback(v.Client, false)
		}
	}

	PendingAuths = newPendingAuths
}