im investigating testing of coroutines in my Android application and following this code lab Advanced Android in Kotlin 05.3: Testing Coroutines and Jetpack integrations
this codelab contains the following code snippet
@ExperimentalCoroutinesApi
val testDispatcher: TestCoroutineDispatcher = TestCoroutineDispatcher()
@ExperimentalCoroutinesApi
@Before
fun setupDispatcher() {
Dispatchers.setMain(testDispatcher)
}
@ExperimentalCoroutinesApi
@After
fun tearDownDispatcher() {
Dispatchers.resetMain()
testDispatcher.cleanupTestCoroutines()
}
however TestCoroutineDispatcher is marked as deprecated with this comment:-
/**
* [CoroutineDispatcher] that performs both immediate and lazy execution of coroutines in tests
* and uses a [TestCoroutineScheduler] to control its virtual clock.
*
* By default, [TestCoroutineDispatcher] is immediate. That means any tasks scheduled to be run without delay are
* immediately executed. If they were scheduled with a delay, the virtual clock-time must be advanced via one of the
* methods on the dispatcher's [scheduler].
*
* When switched to lazy execution using [pauseDispatcher] any coroutines started via [launch] or [async] will
* not execute until a call to [DelayController.runCurrent] or the virtual clock-time has been advanced via one of the
* methods on [DelayController].
*
* @see DelayController
*/
@Deprecated("The execution order of `TestCoroutineDispatcher` can be confusing, and the mechanism of " +
"pausing is typically misunderstood. Please use `StandardTestDispatcher` or `UnconfinedTestDispatcher` instead.",
level = DeprecationLevel.WARNING)
// Since 1.6.0, ERROR in 1.7.0 and removed as experimental in 1.8.0
public class TestCoroutineDispatcher(public override val scheduler: TestCoroutineScheduler = TestCoroutineScheduler()):
TestDispatcher(), Delay, SchedulerAsDelayController
{...}
It is not clear how I should use the suggested alternatives to TestCoroutineDispatcher()
are StandardTestDispatcher
and UnconfinedTestDispatcher
straight replacements for TestCoroutineDispatcher()?
what am I missing?
Seems it is possible to use more elegant solution like runTest()
since 1.6.0
Taken from this SO answer
See the documentation for details on how to use the module.