Short-circuit hooks

pre_commit/commands/run.py

@@ -11,6 +11,8 @@
 import unicodedata
 from typing import Any
 from typing import Collection
+from typing import Generator
+from typing import Iterable
 from typing import MutableMapping
 from typing import Sequence
 
@@ -57,20 +59,20 @@ def _full_msg(
 
 
 def filter_by_include_exclude(
-        names: Collection[str],
+        names: Iterable[str],
         include: str,
         exclude: str,
-) -> list[str]:
+) -> Generator[str, None, None]:
     include_re, exclude_re = re.compile(include), re.compile(exclude)
-    return [
+    return (
         filename for filename in names
         if include_re.search(filename)
         if not exclude_re.search(filename)
-    ]
+    )
 
 
 class Classifier:
-    def __init__(self, filenames: Collection[str]) -> None:
+    def __init__(self, filenames: Iterable[str]) -> None:
         self.filenames = [f for f in filenames if os.path.lexists(f)]
 
     @functools.lru_cache(maxsize=None)
@@ -79,35 +81,33 @@ def _types_for_file(self, filename: str) -> set[str]:
 
     def by_types(
             self,
-            names: Sequence[str],
+            names: Iterable[str],
             types: Collection[str],
             types_or: Collection[str],
             exclude_types: Collection[str],
-    ) -> list[str]:
+    ) -> Generator[str, None, None]:
         types = frozenset(types)
         types_or = frozenset(types_or)
         exclude_types = frozenset(exclude_types)
-        ret = []
         for filename in names:
             tags = self._types_for_file(filename)
             if (
                     tags >= types and
                     (not types_or or tags & types_or) and
                     not tags & exclude_types
             ):
-                ret.append(filename)
-        return ret
-
-    def filenames_for_hook(self, hook: Hook) -> tuple[str, ...]:
-        names = self.filenames
-        names = filter_by_include_exclude(names, hook.files, hook.exclude)
-        names = self.by_types(
-            names,
+                yield filename
+
+    def filenames_for_hook(self, hook: Hook) -> Generator[str, None, None]:
+        names = iter(self.filenames)
+        filtered = filter_by_include_exclude(names, hook.files, hook.exclude)
+        by_types = self.by_types(
+            filtered,
             hook.types,
             hook.types_or,
             hook.exclude_types,
         )
-        return tuple(names)
+        return by_types
 
     @classmethod
     def from_config(
@@ -122,8 +122,8 @@ def from_config(
         # see #1173
         if os.altsep == '/' and os.sep == '\\':
             filenames = [f.replace(os.sep, os.altsep) for f in filenames]
-        filenames = filter_by_include_exclude(filenames, include, exclude)
-        return Classifier(filenames)
+        filtered = filter_by_include_exclude(filenames, include, exclude)
+        return Classifier(filtered)
 
 
 def _get_skips(environ: MutableMapping[str, str]) -> set[str]:
@@ -148,7 +148,7 @@ def _run_single_hook(
         verbose: bool,
         use_color: bool,
 ) -> tuple[bool, bytes]:
-    filenames = classifier.filenames_for_hook(hook)
+    filenames = tuple(classifier.filenames_for_hook(hook))
 
     if hook.id in skips or hook.alias in skips:
         output.write(

pre_commit/meta_hooks/check_hooks_apply.py

@@ -21,7 +21,7 @@ def check_all_hooks_match_files(config_file: str) -> int:
     for hook in all_hooks(config, Store()):
         if hook.always_run or hook.language == 'fail':
             continue
-        elif not classifier.filenames_for_hook(hook):
+        elif not any(classifier.filenames_for_hook(hook)):
             print(f'{hook.id} does not apply to this repository')
             retv = 1
 

pre_commit/meta_hooks/check_useless_excludes.py

@@ -2,6 +2,7 @@
 
 import argparse
 import re
+from typing import Iterable
 from typing import Sequence
 
 from cfgv import apply_defaults
@@ -14,7 +15,7 @@
 
 
 def exclude_matches_any(
-        filenames: Sequence[str],
+        filenames: Iterable[str],
         include: str,
         exclude: str,
 ) -> bool:
@@ -54,9 +55,11 @@ def check_useless_excludes(config_file: str) -> int:
             types = hook['types']
             types_or = hook['types_or']
             exclude_types = hook['exclude_types']
-            names = classifier.by_types(names, types, types_or, exclude_types)
+            by_types = classifier.by_types(
+                names, types, types_or, exclude_types,
+            )
             include, exclude = hook['files'], hook['exclude']
-            if not exclude_matches_any(names, include, exclude):
+            if not exclude_matches_any(by_types, include, exclude):
                 print(
                     f'The exclude pattern {exclude!r} for {hook["id"]} does '
                     f'not match any files',

tests/commands/run_test.py

@@ -1127,8 +1127,8 @@ def test_classifier_empty_types_or(tmpdir):
             types_or=[],
             exclude_types=[],
         )
-        assert for_symlink == ['foo']
-        assert for_file == ['bar']
+        assert tuple(for_symlink) == ('foo',)
+        assert tuple(for_file) == ('bar',)
 
 
 @pytest.fixture
@@ -1142,33 +1142,33 @@ def some_filenames():
 
 def test_include_exclude_base_case(some_filenames):
     ret = filter_by_include_exclude(some_filenames, '', '^$')
-    assert ret == [
+    assert tuple(ret) == (
         '.pre-commit-hooks.yaml',
         'pre_commit/git.py',
         'pre_commit/main.py',
-    ]
+    )
 
 
 def test_matches_broken_symlink(tmpdir):
     with tmpdir.as_cwd():
         os.symlink('does-not-exist', 'link')
         ret = filter_by_include_exclude({'link'}, '', '^$')
-        assert ret == ['link']
+        assert tuple(ret) == ('link',)
 
 
 def test_include_exclude_total_match(some_filenames):
     ret = filter_by_include_exclude(some_filenames, r'^.*\.py$', '^$')
-    assert ret == ['pre_commit/git.py', 'pre_commit/main.py']
+    assert tuple(ret) == ('pre_commit/git.py', 'pre_commit/main.py')
 
 
 def test_include_exclude_does_search_instead_of_match(some_filenames):
     ret = filter_by_include_exclude(some_filenames, r'\.yaml$', '^$')
-    assert ret == ['.pre-commit-hooks.yaml']
+    assert tuple(ret) == ('.pre-commit-hooks.yaml',)
 
 
 def test_include_exclude_exclude_removes_files(some_filenames):
     ret = filter_by_include_exclude(some_filenames, '', r'\.py$')
-    assert ret == ['.pre-commit-hooks.yaml']
+    assert tuple(ret) == ('.pre-commit-hooks.yaml',)
 
 
 def test_args_hook_only(cap_out, store, repo_with_passing_hook):