feat: Introduce compatibility with native namespace packages

google/__init__.py

@@ -14,11 +14,6 @@
 
 """Google namespace package."""
 
-try:
-    import pkg_resources
+import pkgutil
 
-    pkg_resources.declare_namespace(__name__)
-except ImportError:
-    import pkgutil
-
-    __path__ = pkgutil.extend_path(__path__, __name__)  # type: ignore
+__path__ = pkgutil.extend_path(__path__, __name__)  # type: ignore

setup.py

@@ -63,7 +63,6 @@
     long_description=long_description,
     url="https://github.com/googleapis/google-auth-library-python",
     packages=find_packages(exclude=("tests*", "system_tests*")),
-    namespace_packages=("google",),
     install_requires=DEPENDENCIES,
     extras_require=extras,
     python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,!=3.5.*",

tests/test_packaging.py

@@ -0,0 +1,30 @@
+# Copyright 2022 Google LLC
+#
+# 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 os
+import subprocess
+import sys
+
+
+def test_namespace_package_compat(tmp_path):
+    """
+    The ``google`` namespace package should not be masked
+    by the presence of ``google-auth``.
+    """
+    google = tmp_path / 'google'
+    google.mkdir()
+    google.joinpath('othermod.py').write_text('')
+    env = dict(os.environ, PYTHONPATH=str(tmp_path))
+    cmd = [sys.executable, '-m', 'google.othermod']
+    subprocess.check_call(cmd, env=env)