Hi, thanks for posting.

The issue you've encountered here is due to technical constraints. The tests are discovered in a different environment to the one they are executed in, which results in the need for the test parameters to be serialized between domains. This creates consistency problems when dealing with more complex types which can be harder to reliably transfer between domains, especially if the types are very similar and do not have a unique way to express themselves when constructing an identifier for each test name.

I accept that there are situations in which this problem could be overcome by a runner or framework, however, it's very hard for a framework to reliably cater for all scenarios. Generally, people don't realise that a multi-case test with user types is very hard for a test framework to deal with, so when problems appear, it can be very hard to understand what is happening.

This particular constraint exists in Xunit itself, but even if it didn't, we'd likely have ended up introducing it in NCrunch for many of the same reasons they did.

The short answer is that if you want granular test cases being reported by the runner, you'll need to keep their parameters as simple as possible. Perhaps consider passing your type names as strings instead.