TestCoroutineRule

TestCoroutineRule.kt

class TestCoroutineRule(
    val testDispatcher: TestCoroutineDispatcher = TestCoroutineDispatcher()
) : TestWatcher() {

    override fun starting(description: Description?) {
        super.starting(description)
        Dispatchers.setMain(testDispatcher)
    }

    override fun finished(description: Description?) {
        super.finished(description)
        Dispatchers.resetMain()
        testDispatcher.cleanupTestCoroutines()
    }
}

// Usage:

class MyTestClass{

    @get:Rule
    val testCoroutineRule = TestCoroutineRule()

  ...
}