feat: add google.api_core.gapic_v1.version_header

google/api_core/gapic_v1/__init__.py

@@ -18,6 +18,7 @@
 from google.api_core.gapic_v1 import method
 from google.api_core.gapic_v1 import method_async
 from google.api_core.gapic_v1 import routing_header
+from google.api_core.gapic_v1 import version_header
 
 __all__ = [
     "client_info",
@@ -26,4 +27,5 @@
     "method",
     "method_async",
     "routing_header",
+    "version_header",
 ]

google/api_core/gapic_v1/version_header.py

@@ -0,0 +1,29 @@
+# Copyright 2024 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.
+
+API_VERSION_METADATA_KEY = "x-goog-api-version"
+
+
+def to_grpc_metadata(version_identifier):
+    """Returns the gRPC metadata containing the API Version header for the given
+    `version_identifier`.
+
+    Args:
+        version_identifier (str): The version identifier to be sent via metadata.
+
+    Returns:
+        Tuple(str, str): The gRPC metadata containing the API Version metadata key
+            and value.
+    """
+    return (API_VERSION_METADATA_KEY, version_identifier)

tests/unit/gapic/test_version_header.py

@@ -0,0 +1,28 @@
+# Copyright 2024 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 pytest
+
+try:
+    import grpc  # noqa: F401
+except ImportError:
+    pytest.skip("No GRPC", allow_module_level=True)
+
+from google.api_core.gapic_v1 import version_header
+
+
+@pytest.mark.parametrize("version_identifier", ["some_value", ""])
+def test_version_header_to_grpc_metadata(version_identifier):
+    value = version_header.to_grpc_metadata(version_identifier)
+    assert value == (version_header.API_VERSION_METADATA_KEY, version_identifier)