docs(generator): clarify lower-bound google-api-core version comment in _compat.py.j2

Author: hebaalazzeh

packages/gapic-generator/gapic/templates/%namespace/%name_%version/%sub/_compat.py.j2

@@ -20,7 +20,8 @@ try:
         get_universe_domain,
     )
 except ImportError:
-    # TODO(https://github.com/googleapis/google-cloud-python/issues/17813): Remove these fallbacks when google-api-core >= 2.18.0 is the minimum required version.
+    # TODO(https://github.com/googleapis/google-cloud-python/issues/17813): Universe domain support was introduced in google-api-core 2.18.0.
+    # Remove these fallback definitions when google-api-core >= 2.18.0 becomes the minimum required version in generated client setup dependencies.
     def get_default_mtls_endpoint(api_endpoint: Optional[str]) -> Optional[str]:
         """Converts api endpoint to mTLS endpoint."""
         if not api_endpoint:

packages/google-api-core/google/api_core/gapic_v1/requests.py

@@ -65,6 +65,13 @@ def setup_request_id(
                 setattr(request, field_name, str(uuid.uuid4()))
         except (AttributeError, ValueError):
             # Proto-plus messages or other objects
+            if hasattr(request, "_pb"):
+                try:
+                    if not request._pb.HasField(field_name):
+                        setattr(request, field_name, str(uuid.uuid4()))
+                    return
+                except (AttributeError, ValueError):
+                    pass
             if getattr(request, field_name, None) is None:
                 setattr(request, field_name, str(uuid.uuid4()))
     else:

packages/google-api-core/tests/unit/gapic/test_requests.py

@@ -113,15 +113,18 @@ def test_setup_request_id(request_obj, is_proto3_optional, expected):
         assert value == expected
 
 
-def test_setup_request_id_assertion_strictness(mocker):
-    # Mock uuid.uuid4 to return a UUID with trailing characters
-    mock_uuid = mocker.patch("uuid.uuid4")
-    mock_uuid.return_value.__str__.return_value = (
-        "12345678-1234-4123-8123-123456789012-extra"
-    )
+from unittest import mock
 
-    # We expect test_setup_request_id to fail (raise AssertionError) because the UUID is invalid.
-    # If test_setup_request_id uses re.fullmatch, it will fail (raise AssertionError), so pytest.raises passes.
-    # If test_setup_request_id uses re.match, it will NOT fail, so pytest.raises fails!
-    with pytest.raises(AssertionError):
-        test_setup_request_id(MockRequest(), is_proto3_optional=True, expected="uuid")
+
+def test_setup_request_id_assertion_strictness():
+    # Mock uuid.uuid4 to return a UUID with trailing characters
+    with mock.patch("uuid.uuid4") as mock_uuid:
+        mock_uuid.return_value.__str__.return_value = (
+            "12345678-1234-4123-8123-123456789012-extra"
+        )
+
+        # We expect test_setup_request_id to fail (raise AssertionError) because the UUID is invalid.
+        # If test_setup_request_id uses re.fullmatch, it will fail (raise AssertionError), so pytest.raises passes.
+        # If test_setup_request_id uses re.match, it will NOT fail, so pytest.raises fails!
+        with pytest.raises(AssertionError):
+            test_setup_request_id(MockRequest(), is_proto3_optional=True, expected="uuid")