如何在测试规则内使JUnit测试失败

Question

我有一些异步代码，可能会引发JUnit错过的异常（因此测试通过）。

我创建了一个TestRule来将这些异常收集到一个列表中。任何测试完成后，断言将遍历列表，并且如果异常列表为非空，则测试将失败。

我不想在测试完成后失败，而是希望在发生异常时立即失败。可以使用TestRule来做到这一点吗？

我的TestRule

/**
 * Coroutines can throw exceptions that can go unnoticed by the JUnit Test Runner which will pass 
 * a test that should have failed. This rule will ensure the test fails, provided that you use the 
 * [CoroutineContext] provided by [dispatcher].
 */
class CoroutineExceptionRule : TestWatcher(), TestRule {

    private val exceptions = Collections.synchronizedList(mutableListOf<Throwable>())

    val dispatcher: CoroutineContext
        get() = Unconfined + CoroutineExceptionHandler { _, throwable ->
            // I want to hook into test lifecycle and fail test immediately here
            exceptions.add(throwable)
            // this throw will not always fail the test. this does print the stacktrace at least
            throw throwable
        }

    override fun starting(description: Description) {
        exceptions.clear()
    }

    override fun finished(description: Description) {
        // instead of waiting for test to finish to fail it
        exceptions.forEach { throw AssertionError(it) }
    }
}