I have a fairly straightforward example and want to unit test an endpoint that has not response. I have seen examples of using this and it works as expected.

        var harness = new InMemoryTestHarness();
        harness.Consumer<FooBarConsumer>();
        
        await harness.Start();
        await harness.InputQueueSendEndpoint.Send<FooCommand>(new FooCommand());
        
        Assert.IsTrue(await harness.Consumed.Any<FooCommand>());

However, I would like to do this with ServiceProvider so that I can setup and mock dependencies. This is what I have so far

        await using var provider = new ServiceCollection()
            .AddMassTransitTestHarness(cfg =>
            {
                cfg.UsingInMemory((ctx, mem) =>
                {
                    mem.ConfigureEndpoints(ctx);
                });
                cfg.AddConsumer<FooBarConsumer>();
            })
            .BuildServiceProvider(true);

If I try doing the following I get an error stating this hasn’t been registered.

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

The example states to do this instead

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

However by doing this I don’t get access to InputQueueSendEndpoint. It forces me down the route of request and response but there is no output for this endpoint.

        var client = harness.GetRequestClient<FooCommand>();
        await client.GetResponse<FooBar>(new FooCommand());

I guess question is, is it possible to test a consumer who receives a command only with no output using InMemoryTestHarness but also setup its dependencies?