Running the ruff formatter as an Alembic post_write_hooks

[lukecivantos]

Hey all!

I'm currently looking into moving from Black to the Ruff formatter – one issue I'm bumping up against is how I might run the ruff formatter as a post write hook in Alembic. In my alembic.ini file I currently have the code below which runs black & the ruff linter, but I'm not sure what the entrypoint would be for ruff's formatter here.

[post_write_hooks]

# format using "black" - use the console_scripts runner, against the "black" entrypoint
hooks = black
black.type = console_scripts
black.entrypoint = black
black.options = -l 79 REVISION_SCRIPT_FILENAME

# lint with attempts to fix using "ruff" - use the exec runner, execute a binary
hooks = ruff
ruff.type = exec
ruff.executable = %(here)s/.venv/bin/ruff
ruff.options = --fix REVISION_SCRIPT_FILENAME

Any help is appreciated – thanks!

[charliermarsh]

What about something like...

# format using "ruff"
hooks = ruff
ruff.type = exec
ruff.executable = %(here)s/.venv/bin/ruff
ruff.options = format REVISION_SCRIPT_FILENAME

[lukecivantos]

Ah okay so this works for me standalone, but the issue is that you can only define one hook, so then I can't run the linter.

Is there a way to run both the formatter and linter in one line on the executable? If not I'll probably have to write a wrapper that the hook points to.

# format using "ruff"
hooks = ruff
ruff.type = exec
ruff.executable = %(here)s/.venv/bin/ruff
ruff.options = format REVISION_SCRIPT_FILENAME

[caerulescens]

@lukecivantos I was looking for the same answer, and I came across the answer; see here.

So you need something like this:

[post_write_hooks]
hooks = black, ruff

black.type = console_scripts
black.entrypoint = black
black.options = -l 88 REVISION_SCRIPT_FILENAME

ruff.type = exec
ruff.executable = %(here)s/.venv/bin/ruff
ruff.options = --fix REVISION_SCRIPT_FILENAME

[T-256]

Also related: #8232

[bozhidarst]

@charliermarsh
@lukecivantos
@caerulescens
@T-256

I was able to make it work for both ruff lint and ruff format by doing the following:

[post_write_hooks]
hooks = ruff, ruff_format

# lint with attempts to fix using "ruff"
ruff.type = exec
ruff.executable = %(here)s/.venv/bin/ruff
ruff.options = --fix REVISION_SCRIPT_FILENAME

# format using "ruff" - use the exec runner, execute a binary
ruff_format.type = exec
ruff_format.executable = %(here)s/.venv/bin/ruff
ruff_format.options = format REVISION_SCRIPT_FILENAME

Pretty much the issue is that it doesn't allow you to use the same name for two hooks. So just by making sure the hooks are with different names it works.

[rafsaf]

Another solution if you are already using pre-commit with ruff (https://github.com/astral-sh/ruff-pre-commit), for example:

# .pre-commit-config.yaml

repos:
  - repo: https://github.com/astral-sh/ruff-pre-commit
    rev: v0.3.0
    hooks:
      - id: ruff-format

  - repo: https://github.com/astral-sh/ruff-pre-commit
    rev: v0.3.0
    hooks:
      - id: ruff
        args: [--fix]

then, the following hook:

[post_write_hooks]
hooks = pre_commit
pre_commit.type = console_scripts
pre_commit.entrypoint = pre-commit
pre_commit.options = run --files REVISION_SCRIPT_FILENAME

will do the trick and will find underlying path to ruff binary and run it seamlessly, and trigger whatever you have in pre-commit, even more stuff than ruff only.