PairwiseDataSource to avoid cartesian explosion with MatrixDataSource?

[georg-jung]

I currently use xUnit and plan to migrate my project to TUnit. I enjoy using @AArnott's PairwiseData attribute in Xunit.Combinatorial: https://aarnott.github.io/Xunit.Combinatorial/docs/combinatorial-vs-pairwise.html#pairwise-testing

I think NUnit has a similar feature: https://docs.nunit.org/articles/nunit/writing-tests/attributes/pairwise.html

Is this something that would be feasible to add to TUnit in the future? Or do you think this should rather be a plugin in a similar way Xunit.Combinatorial is?

[thomhurst]

If this is widely used in the ecosystem I can consider adding it. Not sure how common it is though.

But for now you could definitely implement it yourself with a custom IDataSourceAttribute implementation 😄

[georg-jung]

Okay, thanks for the super quick response! I'll try creating such plugin and will consider publishing if it works for me.

[thomhurst]

Let me know if ya have any issues

[AArnott]

Pairwise test case generation is complex. I actually copied nunit's algorithm for xunit.combinatorial's PairwiseDataAttribute.
If anyone builds it for TUnit, please share the library as it isn't something trivial we can all implement.

[georg-jung]

I wasn't planning to reinvent the wheel but rather base it heavily on your work 😅.

It's not quite there yet but WIP is available here: https://github.com/georg-jung/TUnit.PairwiseDataSource

The hard parts are basically a copy, but I think it looks promising to get it working. Note that the readme is mostly AI written at this point and I plan to highlight it's close ancestry to yours better (edit: done).

I also think using the exact same strategy / algorithm is an important feature regarding an easy migration path xUnit -> TUnit.

[georg-jung]

It works fine for me now 🎉. Available here: https://www.nuget.org/packages/GeorgJung.TUnit.PairwiseDataSource/ (TUnit is a reserved prefix, so I used my name as a prefix for the packageId)

I hope it's reasonably easy to consume, with TUnit0049 suppression and automatic provision of a global using, as TUnit does itself.

Please let me know if you have any suggestions for improvement.