In .NET Core 2.0 I have a fairly simple MassTransit routing slip that contains 2 activities. This is built and executed in a consumer and it all ties back to an automatonymous state machine. It all works great albeit with a few final clean tweaks needed.
However, I can't quite figure out the best way to write unit tests for my consumer as it builds a routing slip. I have the following code in my consumer:
public async Task Consumer(ConsumerContext<ProcessRequest> context)
{
var builder = new RoutingSlipBuilder(NewId.NextGuid());
SetupRoutingSlipActivities(builder, context);
var routingSlip = builder.Build();
await context.Execute(routingSlip).ConfigureAwait(false);
}
I created the SetupRoutingSlipActivities method as I thought it would help me write tests to make sure the right activities were being added and it simply looks like:
public void SetupRoutingSlipActivities(RoutingSlipBuilder builder, ConsumeContext<IProcessCreateLinkRequest> context)
{
builder.AddActivity(
nameof(ActivityOne),
new Uri("execute_activity_one_example_address"),
new ActivityOneArguments(
context.Message.Id,
context.Message.Name)
);
builder.AddActivity(
nameof(ActivityTwo),
new Uri("execute_activity_two_example_address"),
new ActivityTwoArguments(
context.Message.AnotherId,
context.Message.FileName)
);
}
I tried to just write tests for the SetupRoutingSlipActivities by using a Moq mock builder and a MassTransit InMemoryTestHarness but I found that the AddActivity method is not virtual so I can't verify it as such:
aRoutingSlipBuilder.Verify(x => x.AddActivity(
nameof(ActivityOne),
new Uri("execute_activity_one_example_address"),
It.Is<ActivityOne>(y => y.Id == 1 && y.Name == "A test name")));
Please ignore some of the weird data in the code examples as I just put up a simplified version.
Does anyone have any recommendations on how to do this? I also wanted to test to make sure the RoutingSlipBuilder was created but as that instance is created in the Consume method I wasn't sure how to do it! I've searched a lot online and through the MassTransit repo but nothing stood out.
Look at how the Courier tests are written, there are a number of test fixtures available to test routing slip activities. While they aren't well documented, the unit tests are a working testament to how the testing is used.