Add checkstyle output format

[dmaciel]

Hi

I know the primary goal of php-cs-fixer is to automatically fix code style and not to report the problems. Having said this, my company is starting using php-cs-fixer on the new code, and I believe will be interesting to track the advances through time with a Jenkins report

I already have a working version, if you are interested in this feature I can create a pull request and start a discussion from here

[keradus]

like php-cs-fixer fix --dry-run --report=junit ?

[dmaciel]

Yes and no, Junit can report the number of files with problems, while checkstyle reports show more detail about where are the errors located (file or folder), or you can group by type (The only thing that it's not possible is to get the line where the error is located)

The Junit report will serve to get the overall progress, while the checkstyle reports allow to have a breakdown off the same info

[SpacePossum]

Hi!

Your screenshots show a lot of details which seems of value to me :)
If making a POC in PR form is not a lot work I would be happy to look at it!

Based on some previous tickets I want to be upfront however that we always try to weight new (I/O related) features on the quality of the work, the amount of acceptance (# of users that would use it) and fit for the roadmap of this project, against the amount of work of reviewing and maintaining the feature (i.e. if the usage is high we expect more people to help out ;) ). This might not always be as transparent as one would like.

That said, having a PR would greatly help for us to see the concept in more detail, I'm especially interested in the output format itself and the tooling available to process such about (into, for example, the reports you provided screenshots of).

Thanks for coming here and talk to us and of course for using the fixer! :)

[keradus]

👍 singing under SpacePossum msg.

oooh, so checkstyle is actually a format, I thought t's just a generic name to call a report, cool.
Could you please say who can use it ? (like which CIs/Tools/plugins)

[K-Phoen]

In the PHP ecosystem, this format is used by well-known tools like PHP_CodeSniffer or PHPStan.

Other languages also have tools emitting violations in this format (Java, Rust, JavaScript, …).

And as @dmaciel said, there is a widely used Jenkins CI plugin that know how to read these kind of files to generate super detailed reports.

Integrating PHP-CS-Fixer in Jenkins is already possible, thanks to the junit output format, but style violations are considered as test failures and it automatically fails the build. Being able to report these violations in a different format (the "checkstyle" one) would give us a better granularity when configuring the job failure conditions (in addition to being able to generate more helpful reports).

I guess that other CI servers would also be able to benefit from this output format, though I have to admit that I only use Jenkins.

If you do decide that this feature is needed, I can help with its implementation (and also maintenance, if needed).

[SpacePossum]

I'm still carefully optimistic as I didn't see an example of the output format or some description of it.
The list of supported tooling makes me feel this would be great to have though :)

[keradus]

Yeah, we need format definition first, eg for JUnit we have https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/2.6/doc/junit-10.xsd .

Could you provide such definition (link to it) @K-Phoen ?

[K-Phoen]

Unfortunately, I don't think that an "official" XSD is provided by the "original checkstyle".

I did found a few format definitions like this one from linkedin's repo, but none of them is "official".

[SpacePossum]

LGTM 👍

[K-Phoen]

I'll send a PR tomorrow then :)