Hook fail_fast stops pre-commit if any prior hook fails

[tp832944]

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fail fast hook

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Description

Hook fail_fast says in the documentation that pre-commit will stop if this hook fails, which suggests it is referring only to the present hook. The actual behaviour appears to be that pre-commit will stop if this or any previous hook fails.

Example

Add a Python file containing including a blank line at the end:

def my_function(b=):
    a = "a"

Use the config below and call pre-commit run -a.

Expected behaviour

All three hooks run. The first and third fail.

Observed behaviour

The first two hooks run. The first hook fails and the second hook passes.

Note

I had previously submitted this as a documentation issue (pre-commit/pre-commit.com#945), because I find the actual behaviour quite useful, as it means we can avoid running a slow hook (e.g. pytest) if any other hook has failed. However, @asottile said this is not the intended behaviour, so resubmitting here as a bug.

pre-commit --version

pre-commit 3.6.2

.pre-commit-config.yaml

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: check-ast
      - id: end-of-file-fixer
        fail_fast: true
      - id: double-quote-string-fixer

~/.cache/pre-commit/pre-commit.log (if present)

Log from terminal, not file.

> pre-commit run -a
check python ast.........................................................Failed
- hook id: check-ast
- exit code: 1

file1.py: failed parsing with CPython 3.11.7:

    Traceback (most recent call last):
      File "<path_redacted>\check_ast.py", line 21, in main
        ast.parse(f.read(), filename=filename)
      File "C:\Program Files\Python311\Lib\ast.py", line 50, in parse
        return compile(source, filename, mode, flags,
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "file1.py", line 1
        def my_function(b=):
                         ^
    SyntaxError: expected default value expression

fix end of files.........................................................Passed