MassTransit SagaStateMachine testing shouldn't be this hard, should it?

user_6380475 0
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I'm trying to write unit tests for MassTransit SagaStateMachine.

The SagaStateMachine has some activities associated to it, so I'm having to write a service provider and add it when configuring the receive endpoint.

My issue is when I try to resolve ISagaRepository as InMemorySagaRepository it returns null and hence forth I can't confirm anything actually worked in my mocks.

Is there an easier way to do this? I'm at my wits end.

The activities include a discord socket client which I've mocked and injected in the service provider and you can see my source here: https://github.com/robertkirkham88/NightFuryBot/blob/master/tests/NFB.UI.DiscordBot.Tests/StateMachines/FlightStateMachineTests.cs

Line 146 is where the issue lies but I might be doing something wrong with my setting up the bus. The unit tests on MassTransit and Automatonymous are not helpful and I can't find any other solution on git/stackoverflow.

var repo = this.provider.GetService<ISagaRepository<FlightState>>() as InMemorySagaRepository<FlightState>;
Assert.NotNull(repo);
masstransit
2 Answers

I had the similar problem. I want to test state machine sage with activities resolved via DI. I've tried solution provided by [@Chris Patterson] (https://stackoverflow.com/a/63999346/14864310) with AddMassTransitInMemoryTestHarness method but it looks like the harness does not consume my messages to the saga. It started to work just after adding the following code before harness start:

harness.OnConfigureInMemoryReceiveEndpoint += cfg =>
{
    cfg.ConfigureSagas(provider.GetRequiredService<IBusRegistrationContext>());
}

await harness.Start();

I'm not sure that it's intended or I've missed something.

user_148643100

Version 7.0.4 of MassTransit included container-based configuration for the InMemoryTestHarness, making it easier to configure tests when using a container.

The Release Notes cover usage, which is also shown below.

Based on the code you linked, you would need:

services.AddMassTransitInMemoryTestHarness(cfg =>
{
    cfg.AddSagaStateMachine<FlightStateMachine, FlightState>()
        .InMemoryRepository();

    cfg.AddSagaTestHarness<FlightState>();
});

And then, once the container is built, you can resolve the test harness and start it.

var harness = provider.GetRequiredService<InMemoryTestHarness>();

await harness.Start();

The state machine should already be configured on an endpoint, so your Publish calls should deliver events to the state machine.

Also, you should only need ISagaRepository<T> to check if sagas are present.

user_18820
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