Implicitly registering unit tests in Haskell

Question

I'm new to Haskell, with a C++ background. I'm doing some exercises in Haskell, and I want to implement them as a bunch of functions covered with unit tests, so the testing driver is my only app.

And with my background, I'm looking for something like GTest. HUnit is its analog in Haskell world. But need to explicitly register tests is really annoying - thats tedious and violates DRY principle.

So I was thinking about experimenting with custom testing framework.Seems that template Haskell can be used to automate providing assertion descriptions and registering tests within one module. But how can automatically collect all tests from all linked modules?

Of course, it is always possible to write build script that would grep sources and generate required code, but I wonder, if this can be done in Haskell only?

Answer 1

test-framework-th provides this functionality for test-framework. The simplest thing is to use the defaultMainGenerator function to collect all top-level definitions prefixed with case_ (HUnit) or prop_ (QuickCheck) into test groups.

If you have multiple test groups, you do still need to list them in a main entry point for your tests. There’s probably a way around that, and I guess that’s what you’re really asking about, but honestly I have found little need to break tests into more than a handful of modules. The effort needed to avoid repetition is sometimes less than the effort needed to maintain it.