Stryker Support

[edenworky]

Are there plans to add Stryker support for mutation testing?

[ArtemGovorov]

While I love the idea of mutation testing, and were considering to add it to wallaby at some point, I'm wondering if the feature is a great fit for a continuous test runner.

Wallaby runs tests very frequently, as you type, while mutation testing is probably not something you'd want to do in a continuous manner. I'd rather run it separately at some point after finishing a feature/logical unit of my work.

How do you see mutation testing support in wallaby.js?

[Masterxilo]

I don't see why you would not want continuous mutation testing, especially if you have the resources for it. It can only help you discover more problems. Obviously, wallaby would have to balance running all the tests periodically and trying out mutations. But while I am going to grab a coffee or not working on a piece of code, go ahead and try to kill some mutants for me!

[dbartholomae]

Just came here to leave the exact same suggestion and happy to see someone had the same idea before. To add a bit more flesh on why this would be helpful: Mutation testing is test coverage on steroids. One of the main reasons why I like Wallaby is because it shows me live which parts of the code I haven't tested yet. Using mutation testing for this would make it a lot more accurate and thereby helpful. In an ideal world I'm imagining the following tdd workflow with Stryker: I start writing a test. While typing, wallaby informs me that the code I have written so far actually doesn't run - so I switch over to implementation mode, implementing just enough code to make the test green. If I accidentially write something that is not necessary to make the test green, again, Wallaby points this out (thanks to mutation testing).

[TylerEich]

I'm pretty new to test authorship and I'm adding tests to code I wrote a while ago, so please forgive me if I'm misguided.

It would be very nice to see, close to real time, whether the tests I've written for this file are actually asserting the right things. Seeing an inline counterexample could help me decide whether to add another test or whether my current test should use different assertions.

[azaeng04]

This would be an amazing addition! Currently executing mutation testing on a large project takes quite some time. I feel like Wallaby could decrease that time down tremendously.