ignore-changes-in should only consider non-source files, not source files. The mutate option already exists for including and excluding source files.

[jonssonchristian]

I am running Stryker.NET in a pre-merge pipeline (i.e. on PRs) as a quality control check on testing for new code. I use the since option with the target derived by running git merge-base between the PR branch and the master branch.

The default behaviour is to revert to run all mutations (i.e. no longer only changed CSharp files determined from the diff) if any non-CSharp file has changed. I appreciate that is the safe and robust solution, but in practice changes to non-CSharp files will rarely be relevant to the mutation testing.

I worked out the following setting to consider diffs only on CSharp files.

{
  "stryker-config": {
    "since": {
      "enabled": true,
      "ignore-changes-in": ["**/*", "!**/*.cs*"]
    }
  }
}

I just thought this may be relevant for others as well and suggest including it in the documentation, in the way that negation is covered under the mutate config option. Unless you think this approach is a bad idea.

[rouke-broersma]

I think that is acceptable, we can include the suggestion in the docs provided we are explicit about the risk.

[jonssonchristian]

Unfortunately, I was being silly and did not look at the right results when I verified this.

My solution will not work, as the pattern "**/*" ignores all files, and "!**/*.cs*" does not un-ignore any of them. So basically my setting will result in changes in all files always ignored, and so all mutants always ignored.

Apologies for the confusion.

I can revert to include a long list of file suffixes to ignore, but it would be nice to have the option to do it by negation or have the option to ignore all non-CSharp files.

[rouke-broersma]

Sorry my bad, I was unclear on the semantics of ignore-changes-in. We do not explicitly support inverted matching in ignore-changes-in:

stryker-net/src/Stryker.Core/Stryker.Core/DiffProviders/GitDiffProvider.cs

Line 73 in 6a79711

private void RemoveFilteredOutFiles(DiffResult diffResult)

This results in both patterns being used as ignore patterns.

[jonssonchristian]

Thank you for the feedback. I leave this issue open now in case you consider it relevant to add the functionality to include negation (i.e. the equivalent of since.consider-changes-in) or an option to ignore changes in all non-CSharp files, but of course feel free to close it if not.

[rouke-broersma]

ignore-changes-in should probably be modified to only consider non-source files in the first place, as the mutate option exists for specifying the files to include in mutation already. Once we only consider non-source files your */ should work for your use case.

[jonssonchristian]

ignore-changes-in should probably be modified to only consider non-source files in the first place, as the mutate option exists for specifying the files to include in mutation already. Once we only consider non-source files your */ should work for your use case.

That makes sense.