Subcommands don't output in color (don't think they are connected to a TTY?)

[ashb]

Using prek as my daily driver for Airflow I noticed a difference between prek and pre-commit:

Pre-commit:

Prek:

The two major differences

• 1) No color in the output from ruff check
• 2) The "All checks passed!" from the subcommands/way we parallelize it.

On 2, I like the ability to see the full output some of the time, but it does make the error more confusing to find, so maybe that should only be shown when -vv or something is given?

[potiuk]

Indeed. Colors are important :). And yeah I see the same problem even if I add --color always

I think how pre-commit is doing it - it allocates pseudo-terminal for the hooks. This is also very important for the automated run with git commit because git pre-commit hooks don't even have access at all to the real terminal (not directly at least) even if they are run from a terminal - simply git will not pass the original terminal to the hook.

I had to use "force_terminal = True" in rich library's console for that in order to make it works for producing screenshots of breeze commands and get it working well when git commit was run.

[j178]

Thanks for report!

1. No color in the output from ruff check

pre-commit runs every subcommand with a pty, but we haven’t done that in prek yet. We should add it to match what pre-commit does.

2. The "All checks passed!" from the subcommands/way we parallelize it.

I’m not sure I understand. Does pre-commit also show the same “All checks passed” message?

[potiuk]

I’m not sure I understand. Does pre-commit also show the same “All checks passed” message?

It does but only once or two times.

I think the problem here is a bit different nature. I believe "require_serial" is not respected by prek as well:

      - id: ruff
        name: Run 'ruff' for extremely fast Python linting
        description: "Run 'ruff' for extremely fast Python linting"
        entry: ruff check --force-exclude
        language: python
        types_or: [python, pyi]
        args: [--fix]
        require_serial: true
        additional_dependencies: ['ruff==0.11.13']
        exclude: ^airflow-core/tests/unit/dags/test_imports\.py$|^performance/tests/test_.*\.py$
      - id: ruff-format

We set require_serial: true for ruff because (obviously) it can parallelise checks on its own, there is no need for prek to do it by parallelising and splitting the file list among multiple processes. What happens with pre-commit - it has a limit of maximum lenght of the command line (I think) and if require_serial is set it will either run single command with all files passed or it will just have a few processes that run sequentially each with the "maximum length" subset of the list.

It looks like prek in this case still attempts to split the lists into smaller chunks and run them - either sequentially or in parallel ?

[potiuk]

With #469 we are now at this stage:

I will take a look to make sure PTY is allocated and stdin/stdout are ttys so ruff autodection works without forcing color in either way.