Force Exclude does not work with symlinks

[slorg1]

Describe the bug
I use the force-exclude feature to exclude files living in symlinked directories.
However, it looks like black uses the regexp from force-exclude after the symlink is resolved (not the symlinked path).

$ black -v /path_2_file/application/api/lib/dir_symlinked/__init__.py
Identified `/path_2_file` as project root containing a .git directory.
Using configuration from project root.
line_length: 135
target_version: ['py39']
force_exclude: (?:.*?application/api(?:-ext)?/lib/dir_symlinked/.+)

skip_string_normalization: True
Found input source: "application/lib/ref_dir/__init__.py"
/path_2_file/application/api/lib/dir_symlinked/__init__.py wasn't modified on disk since last run.

All done! ✨ 🍰 ✨
1 file left unchanged.

The resulting error is:

It should have ignored the file based on this path /path_2_file/application/api/lib/dir_symlinked/__init__.py rather than including it based on this path application/lib/ref_dir/__init__.py.
Said differently it used the resolved/resulting path rather than the path through the symlink

Environment

• Black's version: 23.7.0
• OS and Python version: MacOS Ventura 13.4.1, Python 3.9.12,

Additional context

I would be equally happy if I could simply tell black not to follow symlinks.

Thank you in advance for your help!

[slorg1]

Hi,

Thank you for the update, I just tried it using black version 23.9.1 and sadly I got the same result as described in the issue here.

@JelleZijlstra could you please reopen this ticket? Thank you

[slorg1]

@hauntsaninja or @JelleZijlstra little bump on reopening this. Thank you!! 😄

[hauntsaninja]

Thanks, I think this will be fixed once we deduplicate get_sources and gen_python_files

[sth]

The problem in the concrete test case (and why it's not affected by #3846) is likely that the symlinked file is given explicitly on the command line and the command line parameters are separately normalized and checked against excludes:

black/src/black/__init__.py

Lines 642 to 660 in f7174bf

	normalized_path: Optional[str] = normalize_path_maybe_ignore(
	p, root, report
	)
	if normalized_path is None:
	if verbose:
	out(f'Skipping invalid source: "{normalized_path}"', fg="red")
	continue
	if verbose:
	out(f'Found input source: "{normalized_path}"', fg="blue")
	normalized_path = "/" + normalized_path
	# Hard-exclude any files that matches the `--force-exclude` regex.
	if force_exclude:
	force_exclude_match = force_exclude.search(normalized_path)
	else:
	force_exclude_match = None
	if force_exclude_match and force_exclude_match.group(0):
	report.path_ignored(p, "matches the --force-exclude regular expression")
	continue

Probably this code should be adjusted the same way as the code in src/black/files.py.