From 8a0dd01c7e985970e62d3ff57841b0b0c485b8a3 Mon Sep 17 00:00:00 2001
From: Paul Hooijenga <paulhooijenga@gmail.com>
Date: Wed, 25 Oct 2017 09:35:39 +0200
Subject: [PATCH] Implement check-files-matches-any meta hook

---
 .../meta_hooks/check_files_matches_any.py     | 36 +++++++++++++++++++
 pre_commit/repository.py                      |  7 ++++
 tests/commands/run_test.py                    | 33 +++++++++++++++++
 3 files changed, 76 insertions(+)
 create mode 100644 pre_commit/meta_hooks/check_files_matches_any.py

diff --git a/pre_commit/meta_hooks/check_files_matches_any.py b/pre_commit/meta_hooks/check_files_matches_any.py
new file mode 100644
index 00000000..88b4806f
--- /dev/null
+++ b/pre_commit/meta_hooks/check_files_matches_any.py
@@ -0,0 +1,36 @@
+import re
+import sys
+
+import pre_commit.constants as C
+from pre_commit.clientlib import load_config
+from pre_commit.git import get_all_files
+
+
+def files_matches_any(filenames, include):
+    include_re = re.compile(include)
+    for filename in filenames:
+        if include_re.search(filename):
+            return True
+    return False
+
+
+def check_files_matches_any(config_file=None):
+    config = load_config(config_file or C.CONFIG_FILE)
+    files = get_all_files()
+    files_not_matched = False
+
+    for repo in config['repos']:
+        for hook in repo['hooks']:
+            include = hook.get('files', '')
+            if include and not files_matches_any(files, include):
+                print(
+                    'The files pattern for {} does not match any files'
+                    .format(hook['id'])
+                )
+                files_not_matched = True
+
+    return files_not_matched
+
+
+if __name__ == '__main__':
+    sys.exit(check_files_matches_any())
diff --git a/pre_commit/repository.py b/pre_commit/repository.py
index cb53fc85..45389cb4 100644
--- a/pre_commit/repository.py
+++ b/pre_commit/repository.py
@@ -259,6 +259,13 @@ class MetaRepository(LocalRepository):
             'entry': pipes.quote(sys.executable),
             'args': ['-m', 'pre_commit.meta_hooks.check_useless_excludes'],
         },
+        'check-files-matches-any': {
+            'name': 'Check hooks match any files',
+            'files': '.pre-commit-config.yaml',
+            'language': 'system',
+            'entry': pipes.quote(sys.executable),
+            'args': ['-m', 'pre_commit.meta_hooks.check_files_matches_any'],
+        },
     }
 
     @cached_property
diff --git a/tests/commands/run_test.py b/tests/commands/run_test.py
index 27fa9eea..24771d22 100644
--- a/tests/commands/run_test.py
+++ b/tests/commands/run_test.py
@@ -735,6 +735,39 @@ def test_useless_exclude_for_hook(
     )
 
 
+def test_files_match_any(
+        cap_out, repo_with_passing_hook, mock_out_store_directory,
+):
+    config = OrderedDict((
+        ('repo', 'meta'),
+        (
+            'hooks', (
+                OrderedDict((
+                    ('id', 'check-files-matches-any'),
+                )),
+                OrderedDict((
+                    ('id', 'check-useless-excludes'),
+                    ('files', 'foo'),
+                )),
+            ),
+        ),
+    ))
+    add_config_to_repo(repo_with_passing_hook, config)
+
+    _test_run(
+        cap_out,
+        repo_with_passing_hook,
+        opts={'all_files': True},
+        expected_outputs=[
+            b'Check hooks match any files',
+            b'The files pattern for check-useless-excludes '
+            b'does not match any files',
+        ],
+        expected_ret=1,
+        stage=False,
+    )
+
+
 @pytest.yield_fixture
 def modified_config_repo(repo_with_passing_hook):
     with modify_config(repo_with_passing_hook, commit=False) as config: