It seems that `TestCoroutineDispatcher` is waiting...

# coroutines

[marcinmoskala]

It seems that TestCoroutineDispatcher is waiting for cancelled tasks.

@Test
fun test() = runBlockingTest {
    val job = launch {
        launch { delay(1000) }
        launch { delay(1000) }
    }
    delay(100)
    job.cancel()

    // then
    advanceUntilIdle()
    assertEquals(100, currentTime) // Should be true, because after 100 everything is cancelled,
    // but it says expected:<100> but was:<1000>
}

I've created an issue here.

[Joffrey]

Why use delay(100) instead of advanceTimeBy(100) in your test method though?

[marcinmoskala]

I respect both ways, but this one seems more intuitive for me. It is like one coroutine is running, and another is observing it.

[Joffrey]

Yeah in any case both should work I believe. Either I'm missing something or this is a bug

[marcinmoskala]

You mean the code snippet? I think of it as a limitation. I imagine that TestCoroutineDispatcher has a list of registered delays it needs to wait for. The problem is that when a coroutine is cancelled, a registered element is not eliminated from this list. It could be, and it would simplify testing.