Testing MassTransit endpoint configuration in Autofac module - masstransit

Question

I have some endpoint configuration code in an Autofac module that's registering consumers based on conventions that I'd like to unit test. I'm not trying to verify any behaviour of any consumers I just want to check that my setup code is doing what I need it to do. I'm using InMemoryTestHarness but consuming doesn't seem to be working and I'm not sure about the correlation between configuring the bus and registering consumer test harnesses.
To allow the host to be swapped between Rabbit for prod and in memory for tests I have this in my module:
Func<Action<IReceiveConfigurator>, IBusControl> BusFactory = receiveConfig => Bus.Factory.CreateUsingRabbitMq(cfg =>
{
cfg.Host(rabbitMqUrl, hostCfg =>
{
hostCfg.Username(rabbitMqUsername);
hostCfg.Password(rabbitMqPassword);
});
receiveConfig(cfg);
});
For the actual consumer registration in my module I have:
// code to scan assembly and build a list of queue definitions with consumers
...
// consumer registration
builder.AddMassTransit(x =>
{
foreach(var consumerType in consumerTypes)
x.AddConsumer(consumerType);
x.AddBus(context => BusFactory(cfg =>
{
foreach(var queueDef in queueDefs)
cfg.ReceiveEndpoint(queueDef.QueueName, e =>
{
foreach(var consumerDef in queueDef.ConsumerDefs)
e.ConfigureConsumer(context, consumerDef.ConsumerType);
});
});
});
For the unit test setup I am doing:
harness = new InMemoryTestHarness();
var module = new MassTransitModule(typeof(TestMessageConsumer).Assembly)
{
BusFactory = (receiveConfig) =>
{
harness.OnConfigureBus += cfg => receiveConfig(cfg);
Task.WaitAll(harness.Start());
return harness.BusControl;
}
};
var builder = new ContainerBuilder();
builder.RegisterModule(module);
container = builder.Build();
// ensure bus initialisation runs
container.Resolve<IBusControl>();
I've verified in the unit test that Autofac can resolve IBus, IBusControl and concrete consumer classes, as well as, given a message type T an IConsumer<T>.
In my tests, if I do:
await harness.InputQueueSendEndpoint.Send(new TestMessage());
harness.Consumed.Select<TestMessage>().Any().ShouldBeTrue();
then first the test waits on the harness.Consumed line for 30 seconds then the test fails (Any() returns false). I get the same behaviour if I register a consumer harness - plus I'm worried that registering a consumer harness doesn't actually verify my registration.
Have I misunderstood something with the test harness? How would I verify that my consumer config is correct? Is the harness.Consume line taking 30 seconds an indication that I've completely misused the test harness? So many questions...
Thanks,
Daniel
EDIT
Based on the comment from Chris Patterson I've updated my registration to use the MassTransit Autofac integration methods (code updated above) but still getting the same problem.

Answer 1

The test harness creates its own bus instance, and the Consumer, Saga, etc. methods add additional harnesses to that same test harness. If you're resolving a bus from the container as part of your test, you're stuck using that bus. The one in the harness is of no use to you, as are the methods in that harness.
You should separate the testing of your consumers from testing the container registration. And while you're at it, why not use the built-in container support for configuring endpoints, etc. instead of writing it yourself? I believe there is an extension method for .AddMassTransit to AddConsumersFromContainer where you specify the container. This makes it usable with previously loaded modules that added consumers to the container, where the bus is in its own module.