feature request: allow for user-defined formatters

[otosky]

Hi again!

Is there an appetite for allowing formatters to be defined by users, registered, and then discovered by the CLI?

I like the plain formatter, but find myself wanting to tweak the output to remove some things that I don't need (like project scores and model scores, etc - I'm only concerned with the rule violations) when running the lint command. As a workaround, I end up parsing the json-formatted output and running some extra script-y code to format the output (within a Github Action) the way I'd like, with some added niceties from rich that this application doesn't need to take on as a core dependency. It would be nice if I was able to hook in a custom formatter instead, though!

[jochemvandooren]

Hey @otosky ! Thanks for opening an issue.

Before going into custom formatters: what would you say is a perfect format? Only the linted object + the violated rule? Nothing more?

[otosky]

My ideal would be something like this with only lint failures shown:

<Linted Object 1>
Rule Violation: <rule name>
Details: <Message>

Rule Violation: <rule name>
Details: <Message>
...
<Linted Object 2>
Rule Violation: <rule name>
Details: <Message>
...

Summary:
<N> failed models
<N> failed sources
etc

As I'm writing this, perhaps there's also a semantic difference in my mind to a command like lint vs a command like report. What do you think?

[jochemvandooren]

Ok, interesting! So what I understand is that you would like to remove the scores and add some summary. It sounds like a specific use-case instead of something that we would like to implement for all users.

Maybe supporting custom formatters would be the way to go here! At the point of writing, I am not sure how complicated it would be to add this feature to be honest, but I think it can offer the needed flexibility for everyone!

With regards to lint and report , I don't really know what report would do and if we need this extra command!