Add a paragraph about DoNotParallelize somewhere in the doc

[dlebansais]

This is a simple suggestion to document the existence of the DoNotParallelize attribute somewhere in your doc.

I'm unsure about the exact version, but recent versions of MSTest.TestFramework allow us to specify test parallelization. This breaks Stryker for me. I had to include these lines in my AssemblyInfo.cs:

#if DO_NOT_PARALLELIZE_TEST_FOR_STRYKER
[assembly: DoNotParallelize]
#else
[assembly: Parallelize(Scope = /* Choose your level here */)]
#endif

Thank you for a great product!

[rouke-broersma]

In what way does this break? We set concurrency to 1 using runSettings so preferably we extend that to support this new configuration option instead of documenting.

[dlebansais]

I did not try this setting, and it sounds like a better option than my workaround, I'll try that.

To answer your question, my score used to be 100% until I updated MSTest.TestFramework and added [assembly: Parallelize(Scope = ...)], then it went down to less than 50%.

[rouke-broersma]

I did not try this setting, and it sounds like a better option than my workaround, I'll try that.

To answer your question, my score used to be 100% until I updated MSTest.TestFramework and added [assembly: Parallelize(Scope = ...)], then it went down to less than 50%.

I think you misunderstood, Stryker automatically adds that setting to runSettings when we start mutation testing. It seems like it's not working with this new option so we need to figure out how to configure it automatically.

[dupdob]

I checked the doc: the settings have completely changed indeed:
https://learn.microsoft.com/en-us/visualstudio/test/configure-unit-tests-by-using-a-dot-runsettings-file?view=vs-2022

By default tests run concurrently. No way to explicitly disable it, but we may limit to 1 worker