Android 在单元测试下断言协程未完成

我有一个可挂起的函数，我想断言，在某些情况下，它不会以结果来完成.我try 编写以下扩展，它的目标是在断言作业(job)是否完成之前等待5秒(我认为这个判断足以知道挂起的对象仍处于挂起状态):

First Approach:个

// Extension Function
fun <T> TestScope.assertNotCompleted(block: suspend CoroutineScope.() -> T) {
    val result = async { block }
    advanceTimeBy(5000L)
    val isBlockComplete = result.isCompleted
    assertThat(isBlockComplete, equalTo(false))
}

// Usage
@Test
fun `Given no value is ready, when waitForValue is called, then the suspendable function is not complete`() =
    runTest {
        assertNotCompleted {
            someClass.waitForValue() 
        }
    }

然而，在这种情况下，当result.isCompleted应该为FALSE时，它总是返回TRUE.如果我go 掉advanceTimeBy(5000L)，那么result.isCompleted总是返回false，即使我修改测试以实际返回一些东西.

我试过另一种方法，用getCompletionExceptionOrNull()投出IllegalStateException分.这实际上是有效的，但它导致了一个奇怪的接口，在该接口中，我们需要使用"Expect"属性来注释使用它的每个测试.如果可能的话，我想避免这种情况，因为测试中的其他地方可能会抛出异常，因此测试可能会不正确地通过.

Second Approach:个

// Extension Function
@OptIn(ExperimentalCoroutinesApi::class)
fun <T> TestScope.assertNotCompleted(block: suspend CoroutineScope.() -> T) {
    async(block = block).run {
        this@assertNotCompleted.advanceTimeBy(5000L)
        getCompletionExceptionOrNull()
    }
}

// Usage - wanting to avoid the need for expected property
@Test(expected = IllegalStateException::class)
fun `Given no value is ready, when waitForValue is called, then the suspendable function is not complete`() =
    runTest {
        assertNotCompleted {
            someClass.waitForValue() 
        }
    }

我确实try 过捕捉这个异常，但是测试要么总是通过，要么总是失败，这取决于advanceTimeBy(5000L)的位置--这与可挂起的对象能否完成无关.

Thrid Approach:个

// Extension Function
@OptIn(ExperimentalCoroutinesApi::class)
fun <T> TestScope.assertNotCompleted(block: suspend CoroutineScope.() -> T) {
    runCatching {
        val result = async { 
            block
            // advanceTimeBy(5000L) Test ALWAYS passes
        }
        // advanceTimeBy(5000L) Test ALWAYS fails
        result.getCompletionExceptionOrNull()
    }.also { 
        assertThat(it.isFailure, equalTo(true))
    }
}

// Usage is same as first approach

先谢谢你.