Add check for illegal Widnows names

Fixes pre-commit#589

.pre-commit-hooks.yaml

@@ -40,6 +40,11 @@
     language: python
     types: [text, executable]
     stages: [commit, push, manual]
+-   id: check-illegal-windows-names
+    name: check illegal windows names
+    entry: Illegal windows filenames detected
+    language: fail
+    files: '(?i)(^|/)(CON|PRN|AUX|NUL|COM[1-9]|LPT[1-9])(\.|/|$)'
 -   id: check-json
     name: check json
     description: checks json files for parseable syntax.

README.md

@@ -51,6 +51,9 @@ Checks for a common error of placing code before the docstring.
 #### `check-executables-have-shebangs`
 Checks that non-binary executables have a proper shebang.
 
+#### `check-illegal-windows-names`
+Check for files that cannot be created on Windows.
+
 #### `check-json`
 Attempts to load all json files to verify syntax.
 

tests/check_illegal_windows_names_test.py

@@ -0,0 +1,46 @@
+from __future__ import annotations
+
+import os.path
+import re
+
+import pytest
+
+from pre_commit_hooks.check_yaml import yaml
+
+
+@pytest.fixture(scope='module')
+def hook_re():
+    here = os.path.dirname(__file__)
+    with open(os.path.join(here, '..', '.pre-commit-hooks.yaml')) as f:
+        hook_defs = yaml.load(f)
+    hook, = (
+        hook
+        for hook in hook_defs
+        if hook['id'] == 'check-illegal-windows-names'
+    )
+    yield re.compile(hook['files'])
+
+
+@pytest.mark.parametrize(
+    's',
+    (
+        pytest.param('aux.txt', id='with ext'),
+        pytest.param('aux', id='without ext'),
+        pytest.param('AuX.tXt', id='capitals'),
+        pytest.param('com7.dat', id='com with digit'),
+    ),
+)
+def test_check_illegal_windows_names_matches(hook_re, s):
+    assert hook_re.search(s)
+
+
+@pytest.mark.parametrize(
+    's',
+    (
+        pytest.param('README.md', id='standard file'),
+        pytest.param('foo.aux', id='as ext'),
+        pytest.param('com.dat', id='com without digit'),
+    ),
+)
+def test_check_illegal_windows_names_does_not_match(hook_re, s):
+    assert hook_re.search(s) is None