test(python-namespaces): add test for namespace name validation

tests/unit/core/python/namespaces/test_validate_namespace_name.py

@@ -0,0 +1,52 @@
+# Copyright 2026 jCloud
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest
+
+from src.jcloud_docsgen.core.python.namespaces import validate_namespace_name
+
+
+@pytest.mark.parametrize(
+    'name,expected',
+    [
+        ('a', True),
+        ('namespace', True),
+        ('match', True),
+        ('case', True),
+        ('type', True),
+        ('_', True),
+        ('__', True),
+        ('___', True),
+        ('_a', True),
+        ('_a_', True),
+        ('_a.', False),
+        ('a.b', False),
+        ('a-b', False),
+        ('a.', False),
+        ('a-', False),
+        ('.a', False),
+        ('-a', False),
+        ('.a.', False),
+        ('-a-', False),
+        ('.', False),
+        ('a-.b', False),
+        ('"', False),
+        ('""', False),
+        ('def', False),
+        ('class', False),
+        ('import', False),
+    ],
+)
+def test_validate_namespace_name(name, expected):
+    assert validate_namespace_name(name) == expected