File that fails check should give some indication of the formatting that was missing.

[belav]

When the --check option is used, the output only contains if a file was not formatted. It doesn't contain any indication of what part of the file wasn't formatted.
Theoretically you can just run csharpier on the file, but in the case where the --check appears to be a false positive, not having a message means it is harder to track down why it failed.

[belav]

I can reproduce this by downloading the zip of the repo and running --check against that. That means I should be able to use the debug version to step through what is going on.

[belav]

It appears that SyntaxNodeComparerTests formats differently based on if it has \r\n or \n as line endings. So line endings must be included somehow in the width of strings.