GitHub actions output format

[Splines]

Current problem

GitHub actions/scripts can output a special log syntax to create warning/error messages directly in the GitHub UI. This is awesome, since you will see the warnings/errors in the summary of your last run and directly in the Files changed tab in pull requests (PRs). As an example, consider this image:

RuboCop (the linter/formatter for Ruby code) has an "GitHub Actions Formatter" directly included:

Useful for GitHub Actions. Formats offenses as workflow commands to create annotations in GitHub UI.

You can use it like this:

rubocop --format github

and everything is ready to go.

Desired solution

I've seen that Pylint allows to specify the --output-format command line flag and that a new JSON2 reporter was added recently. I wonder if there is also a GitHub reporter available. I haven't found one yet after some digging around in search engines ;)

Additional context

The feature could then be used as follows:

pylint --output-format=github

[Pierre-Sassoulas]

Thank you for opening this issue, great suggestion !

[crazybolillo]

If no one is working on this I can do it

[crazybolillo]

So I was checking the code and it seems like this could be done with --msg-template, in fact some reporters are marked as deprecated and suggest using --msg-template directly instead. Would this be the same case?

[DanielNoord]

I think trying if this works with a template would be nice. Then we can just document that in the documentation. You could start there?

[Splines]

I think trying if this works with a template would be nice. Then we can just document that in the documentation.

Once it works as template string, maybe it'd still be beneficial to have something like github available as key one can pass to the --output-format (or a similiar?) flag such that users won't have to add something like

pylint --msg-template='{msg_id}:{line:3d},{column}: {obj}: {msg}' # example from the docs

and can instead simply go ahead and run

pylint --output-format=github   # or a similar cli flag

without having to know the "internals" of how the messages are to be outputted in order to be GitHub-action-consumable? But maybe that's just me being too lazy as a user.

[DanielNoord]

No I think that is fair. We have recently added a new json reporter. You can probably look at that PR to see what stuff you'd need to add for it to work.

I'm on mobile right now so can't easily link the PR myself, sorry!

[Pierre-Sassoulas]

I also like the shortcut. Lazy users are the best users 😄
Here's hopefuly a link to the code of json reporters (other exemples are available in this directory) : https://github.com/pylint-dev/pylint/blob/main/pylint%2Freporters%2Fjson_reporter.py

[crazybolillo]

I made a dummy test with my PR changes:

https://github.com/zoftko/balba/pull/2/files

Just wondering if we should mark all annotations as error? Or make some sort of mapping between pylint message types and github annotation types.

For example Pylint has fatal, error, warning, convention, refactor and information type messages. Github has notice, warning and error annotations.

[Pierre-Sassoulas]

It looks really great. I think pylint fatal should break the build, error should be mapped to error, warning to warning and pylint convention and refactor to github's notice.

[Splines]

@crazybolillo Many thanks for the quick implementation and thanks to everyone involved in the PR ❤