I'm relative new to Kotlin and I'm trying to test ...

# coroutines

[Leonardo Borges]

I'm relative new to Kotlin and I'm trying to test a use case which has a suspend function. The function calls an API, which I'm mocking using mockK.

class MyUseCase {
	operator suspend fun invoke(val someId: UUID) = withContext(<http://Dispatchers.IO|Dispatchers.IO>) {
		val response = someAPI.requestDataById(someId)
		// process the response...
	}
}

Using JUnit5, there are a few exceptions I want to test, such as below:

@Test
fun testCustomExceptionIsThrown() {
	coEvery { someAPI.requestDataById(someId) returns someData }
	val thrown = assertThrows<CustomException> { 
		runBlocking { myUseCase(someId) }
	}
	assertEquals("customExceptionMessage", thrown.message)
}

This is always returning an JobCancellationException: Parent job is Completed; and I actually can't figure out why.
Also, is this the right way to use those libraries?

[xiaobailong24]

You should use `runBlockingTest`: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-test/kotlinx.coroutines.test/run-blocking-test.html