feat: ignore certain folders

src/zope/testrunner/find.py

@@ -25,7 +25,12 @@
 from zope.testrunner.filter import build_filtering_func
 
 
-identifier = re.compile(r'[_a-zA-Z]\w*$').match
+identifier = re.compile(r'[_a-z]\w*$', re.I).match
+IGNORE_FOLDERS = {
+    '.git',
+    'node_modules',
+    '__pycache__'
+}
 
 
 class DuplicateTestIDError(Exception):
@@ -293,7 +298,9 @@ def update_root2ext(dirname, noext, withext):
     for (p, package) in test_dirs(options, {}):
         for dirname, dirs, files in walk_with_symlinks(options, p):
             root2ext = {}
-            dirs[:] = [d for d in dirs if identifier(d)]
+            dirs[:] = [
+                d for d in dirs if identifier(d) and d not in IGNORE_FOLDERS
+            ]
             d = os.path.split(dirname)[1]
             if tests_pattern(d) and contains_init_py(options, files):
                 # tests directory

src/zope/testrunner/tests/test_find.py

@@ -81,3 +81,19 @@ def test_DuplicateTestIDError_message_contains_all_test_ids(self):
         self.assertIn(
             os.path.join('testrunner-ex', 'sampletestsl.rst'),
             str(e.exception))
+
+
+class TestIdentifierMatches(unittest.TestCase):
+    """Test which folders are ignored by the test runner."""
+
+    def test_ignored(self):
+        folders = ('spaces are bad', 'dashes-bad', 'ünicodeLeading')
+        for name in folders:
+            self.assertFalse(find.identifier(name), f'{name} is accepted')
+
+    def test_accepted(self):
+        folders = (
+            'random', 'CamelCase', 'Under_scores', '_leading_scores', 'unicöde'
+        )
+        for name in folders:
+            self.assertTrue(find.identifier(name), f'{name} is not accepted')