How to test a state stored aggregate that doesn't produce events - spring-boot

Question

I want to test a state stored aggregate by using AggregateTestFixture. However I get AggregateNotFoundException: No 'given' events were configured for this aggregate, nor have any events been stored. error.
I change the state of the aggregate in command handlers and apply no events since I don't want my domain entry table to grow unnecessarily.
Here is my external command handler for the aggregate;
open class AllocationCommandHandler constructor(
private val repository: Repository<Allocation>,
) {
#CommandHandler
fun on(cmd: CreateAllocation) {
this.repository.newInstance {
Allocation(
cmd.allocationId
)
}
}
#CommandHandler
fun on(cmd: CompleteAllocation) {
this.load(cmd.allocationId).invoke { it.complete() }
}
private fun load(allocationId: AllocationId): Aggregate<Allocation> =
repository.load(allocationId)
}
Here is the aggregate;
#Entity
#Aggregate
#Revision("1.0")
final class Allocation constructor() {
#AggregateIdentifier
#Id
lateinit var allocationId: AllocationId
private set
var status: AllocationStatusEnum = AllocationStatusEnum.IN_PROGRESS
private set
constructor(
allocationId: AllocationId,
) : this() {
this.allocationId = allocationId
this.status = AllocationStatusEnum.IN_PROGRESS
}
fun complete() {
if (this.status != AllocationStatusEnum.IN_PROGRESS) {
throw IllegalArgumentException("cannot complete if not in progress")
}
this.status = AllocationStatusEnum.COMPLETED
apply(
AllocationCompleted(
this.allocationId
)
)
}
}
There is no event handler for AllocationCompleted event in this aggregate, since it is listened by an other aggregate.
So here is the test code;
class AllocationTest {
private lateinit var fixture: AggregateTestFixture<Allocation>
#Before
fun setUp() {
fixture = AggregateTestFixture(Allocation::class.java).apply {
registerAnnotatedCommandHandler(AllocationCommandHandler(repository))
}
}
#Test
fun `create allocation`() {
fixture.givenNoPriorActivity()
.`when`(CreateAllocation("1")
.expectSuccessfulHandlerExecution()
.expectState {
assertTrue(it.allocationId == "1")
};
}
#Test
fun `complete allocation`() {
fixture.givenState { Allocation("1"}
.`when`(CompleteAllocation("1"))
.expectSuccessfulHandlerExecution()
.expectState {
assertTrue(it.status == AllocationStatusEnum.COMPLETED)
};
}
}
create allocation tests passes, I get the error on complete allocation test.

Answer 1

The givenNoPriorActivity is actually not intended to be used with State-Stored aggregates. Quite recently an adjustment has been made to the AggregateTestFixture to support this, but that will be released with Axon 4.6.0 (the current most recent version is 4.5.1).
That however does not change the fact I find it odd the complete allocation test fails. Using the givenState and expectState methods is the way to go. Maybe the Kotlin/Java combination is acting up right now; have you tried doing the same with pure Java, just for certainty?
On any note, the exception you share comes from the RecordingEventStore inside the AggregateTestFixture. It should only occur if an Event Sourcing Repository is used under the hood (by the fixture) actually since that will read events. What might be the culprit, is the usage of the givenNoPriorActivity. Please try to replace that for a givenState() providing an empty Aggregate instance.