ci: add mega-linter for linting

[eitsupi]

No description provided.

[etiennebacher]

Why do we need this? From what I can see it will use lintr and cargo clippy for linting so what is the advantage of using this compared to our existing formatting tools in the taskfile? Does this push changes automatically?

[eitsupi]

This is required for everything but R and Rust.
For example, there is often a problem with spaces at the end of the NEWS.md file, but such things are automatically detected.
It also includes parsing of things that are difficult to run locally, such as actionlint's inspection of GitHub Actions files.

Some linters have automatic fixes (auto commit), but I have turned them off for now.
This is because commit with GitHub default token does not trigger other actions and could stop things like R CMD check.

[etiennebacher]

Looks like a very big tool for not many linting usages (the workflow takes about 2min to lint yaml and markdown files and we don't have many of them). If I remember correctly, it was Prettier that fixed the Markdown spaces for you locally. Maybe we could add a format-other task that calls the Prettier CLI locally?

I see they also have a Github action, is it worth trying it as well?

[eitsupi]

What I really want to run is editorconfg, but I can't find the proper action in GitHub Actions.

Yes, the execution time is relatively long, but it is far better than no check.

[eitsupi]

@etiennebacher I want to merge this so can you please take a look?
(I am tired of having extra whitespace added to Markdown files being missed and merged.)

[etiennebacher]

I really think this is overkill for spaces in Markdown files. I merge it so we can move on but I'll open an issue to see if Prettier has a github action that is less massive

[eitsupi]

I really think this is overkill for spaces in Markdown files. I merge it so we can move on but I'll open an issue to see if Prettier has a github action that is less massive

I agree with that. However, what I am concerned about Mega-Linter is that it also reliably performs checks for things that are difficult to inspect locally, such as GitHub Actions.