Used --statistics option does hide the rule violations

[ssbarnea]

The fact that ruff check --statistics does disabled the output of effective line violations makes it impossible to us this as an addon option for improved output, especially when using ruff using as a pre-commit hook.

If that was its initial intention, it was implemented wrongly because it should have being just --output-format=statistics if it replaces the output.

This could be sorted by ensuring that --statistics does not affect the output format and that is output goes to stderr so it would not break tools that might process the standard output formats, which could be machine parseable.

Story: As an user, I want to see some stats about found violations, after they are listed.

[MichaReiser]

I understand your use case. But just writing to stderr is not necessarily a solution because --statistics also impacts other output formats.

❯ uvx ruff check . --statistics --output-format json > output.json

test on  main [$✘!?] via 🐍 v3.12.7 
❯ bat output.json
───────┬───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: output.json
───────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ [
   2   │   {
   3   │     "code": "I001",
   4   │     "name": "unsorted-imports",
   5   │     "count": 6,
   6   │     "fixable": true
   7   │   }
   8   │ ]

I think the ask here is to make --statistics additive. Ruff should include the statistics in the output in addition to the individual diagnostics. But I'm not 100% sure about that. This requires fleshing out the UX first