Add --exclude to large files filter

Author: tmi

README.md

@@ -26,6 +26,7 @@ Add this to your `.pre-commit-config.yaml`
 #### `check-added-large-files`
 Prevent giant files from being committed.
   - Specify what is "too large" with `args: ['--maxkb=123']` (default=500kB).
+  - Optionally exclude glob-like patterns with `args: ['--exclude=uv.lock,examples/*ipynb']`
   - Limits checked files to those indicated as staged for addition by git.
   - If `git-lfs` is installed, lfs files will be skipped
     (requires `git-lfs>=2.2.1`)

pre_commit_hooks/check_added_large_files.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import argparse
+from fnmatch import fnmatch
 import math
 import os
 import subprocess
@@ -34,12 +35,17 @@ def find_large_added_files(
         filenames: Sequence[str],
         maxkb: int,
         *,
+        exclude: list[str]|None = None,
         enforce_all: bool = False,
 ) -> int:
     # Find all added files that are also in the list of files pre-commit tells
     # us about
     retv = 0
-    filenames_filtered = set(filenames)
+    exclude = [] if not exclude else exclude
+    filenames_filtered = {
+        fname for fname in filenames
+        if not any(fnmatch(fname, pat) for pat in exclude)
+    }
     filter_lfs_files(filenames_filtered)
 
     if not enforce_all:
@@ -68,12 +74,17 @@ def main(argv: Sequence[str] | None = None) -> int:
         '--maxkb', type=int, default=500,
         help='Maximum allowable KB for added files',
     )
+    parser.add_argument(
+        '--exclude', type=str, default='',
+        help="Comma-separated list of glob-style patterns to be excluded",
+    )
     args = parser.parse_args(argv)
 
     return find_large_added_files(
         args.filenames,
         args.maxkb,
         enforce_all=args.enforce_all,
+        exclude=args.exclude.split(',')
     )
 
 

tests/check_added_large_files_test.py

@@ -42,6 +42,20 @@ def test_add_something_giant(temp_git_dir):
         # Should pass with higher bound
         assert find_large_added_files(['f.py'], 10) == 0
 
+def test_use_exclude(temp_git_dir):
+    with temp_git_dir.as_cwd():
+        temp_git_dir.join('uv.lock').write('a' * 10_000)
+        temp_git_dir.join('big.baddie').write('a' * 10_000)
+
+        cmd_output('git', 'add', 'uv.lock')
+        cmd_output('git', 'add', 'big.baddie')
+
+        # should fail due to big baddie as thats not excluded
+        assert find_large_added_files(['uv.lock', 'big.baddie'], 1, exclude=['*.lock']) == 1
+        # should pass when all files excluded, with both expand and exact matches
+        assert find_large_added_files(['uv.lock'], 1, exclude=['*.lock']) == 0
+        assert find_large_added_files(['uv.lock'], 1, exclude=['uv.lock']) == 0
+
 
 def test_enforce_all(temp_git_dir):
     with temp_git_dir.as_cwd():