Pre-commit hook with --remove-all-unused-imports always passes

[rob-levy-minimum]

If you specify --remove-all-unused-imports in the args section of .pre-commit.yaml then the hook always passes, even when you have unused imports.

Case study

.pre-commit.yaml

repos:
  - repo: https://github.com/PyCQA/autoflake
    rev: v2.2.1
    hooks:
      - id: autoflake
        args: [--remove-all-unused-imports]

foo.py

import random

print("Does nothing")

Try commiting foo.py and the hook will pass!

If I remove the arg then the hook works as expected.

It works as expected when running from the command line:

$ autoflake --remove-all-unused-imports foo.py
--- original/foo.py
+++ fixed/foo.py
@@ -1,3 +1,2 @@
-import random

 print("Does nothing")

[fsouza]

@rob-levy-minimum does adding --in-place fix it? I wonder if there's a way for us to detect that we're being invoked by pre-commit and change the default value for for that flag.

[rob-levy-minimum]

Oh nice. Adding --in-place makes it work! Maybe just add it to the README describing how to set it up as a hook, that's all that's required I'd say.