Nx: Add support for Mutation Testing

[danieldanielecki]

It could have been great to have in a freshly generated monorepo a support for mutation testing, Stryker supports Jest & TypeScript.

[SebasG22]

I can help with that. Instead of making it mandatory when generating a monorepo, it would be that it could be easily integrated into existing projects through schematics.

[mehrad-rafigh]

This would be nice indeed.

I am thinking of adding a new flag to app and lib generation --mutation-test-runner
It could have noneas the default option and stryker-mutator as an option to invoke the schematic and setup everything needed.

What do guys think? I would have the time to tackle this.

[SebasG22]

Awesome, let's do it. @mehrad-rafigh
I will start working on this feature this weekend.
My plan is to generate the basic schematic for stryker then we can integrate this option to the libs and apps schematic.

[mehrad-rafigh]

@SebasG22 Sounds good! If I can help you in any ways, let me know :)

[SebasG22]

Hi @mehrad-rafigh @danieldanielecki, I made good progress these days on this feature and be able to implement stryker builder with partial support for jest and use it in an nx repo.
You can take a look here https://github.com/SebasG22/nx-mutation
To run the builder use: yarn ng run demo2:mutate.

Next steps:

• Support karma test runner
• Improve jest configuration to handle tsconfig paths
• Generate schematics for stryker.config.js
• Support stryker.config.js

[SebasG22]

Hey folks,
I'm happy to announce that I was able to create the stryker schematics & builder that supports jest and karma runners. I will submit the PR to be part of nrwl/nx on this weekend. 🚀

Note: You can take a look at NX Mutation Examples

[SebasG22]

Hey folks,
It's amazing to know that nx will support mutation testing soon...
https://github.com/nrwl/nx/pull/1925

[davidgaulin]

@SebasG22 are you moving forward with the nx-stryker plugin as suggested in our your PR? interesting functionality for sure!

[SebasG22]

Hey @davidgaulin,
Sure. I'm working hard to move it as a plugin for angular and nx projects.
😄

[twittwer]

@SebasG22 Thx for the hard work you already done
Do you make progress or maybe need help?

Maybe the new Plugin schematics can reduce some work - https://nx.dev/angular/guides/nx-plugin

[danieldanielecki]

@twittwer I just opened an issue that I couldn't fetch the package. Looks like @SebasG22 is about releasing it in the near future.

[FrozenPandaz]

Hi, sorry about this.

This was mislabeled as stale. We are testing ways to mark _not reproducible_ issues as stale so that we can focus on actionable items but our initial experiment was too broad and unintentionally labeled this issue as stale.