feat: move request-id auto-population logic to gapic_v1 public helpers

[hebaalazzeh]

Introduces method_helpers module containing setup_request_id helper. Exposes the module as public in gapic_v1.

The unit tests in test_method_helpers.py are now identical to the generator's original test template test_service.py.j2 (with the exception of our added None request test case).

[gemini-code-assist]

Code Review

This pull request introduces a new helper module method_helpers containing a setup_request_id function to populate a UUID4 field in requests if not already set, supporting dicts, protobuf, and proto-plus messages. It also adds a session-scoped pytest fixture to isolate unit tests from workstation mTLS environments, updates a nox session configuration, and relaxes a timing assertion in test_bidi.py. As there are no review comments, no additional feedback is provided.

[hebaalazzeh]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces a new helper module method_helpers containing the setup_request_id function, which populates a UUID4 field in request objects or dictionaries if not already set, along with corresponding unit tests. The review feedback suggests adding a None check at the beginning of setup_request_id and using a default value in getattr to prevent potential AttributeErrors, as well as adding a test case to verify graceful handling of None requests.

[gemini-code-assist]

To ensure robust defensive programming and prevent potential runtime errors, we should add a None check at the beginning of setup_request_id. Additionally, using getattr(request, field_name, None) instead of getattr(request, field_name) in the else block prevents an AttributeError if the attribute is completely missing from the object.

def setup_request_id(request: Any, field_name: str, is_proto3_optional: bool) -> None:
    """Populate a UUID4 field in the request if it is not already set.

    Args:
        request (Union[google.protobuf.message.Message, dict]): The
            request object.
        field_name (str): The name of the field to populate.
        is_proto3_optional (bool): Whether the field is proto3 optional.
    """
    if request is None:
        return

    if isinstance(request, dict):
        if is_proto3_optional:
            if field_name not in request:
                request[field_name] = str(uuid.uuid4())
        elif not request.get(field_name):
            request[field_name] = str(uuid.uuid4())
        return

    if is_proto3_optional:
        try:
            # Pure protobuf messages
            if not request.HasField(field_name):
                setattr(request, field_name, str(uuid.uuid4()))
        except (AttributeError, ValueError):
            # Proto-plus messages or other objects
            if not getattr(request, field_name, None):
                setattr(request, field_name, str(uuid.uuid4()))
    else:
        if not getattr(request, field_name, None):
            setattr(request, field_name, str(uuid.uuid4()))

References

1. When processing optional parameters with a helper function, prefer placing the null or None check within the function body rather than at the call site to simplify the calling code and improve encapsulation.

[gemini-code-assist]

Add a test case to verify that setup_request_id handles a None request gracefully without raising any exceptions.

Suggested change

	# test custom non-iterable object wrapper
	req_obj3 = CustomRequestWrapper()
	setup_request_id(req_obj3, "request_id", True)
	assert req_obj3.request_id != ""
	uuid.UUID(req_obj3.request_id)
	# test custom non-iterable object wrapper
	req_obj3 = CustomRequestWrapper()
	setup_request_id(req_obj3, "request_id", True)
	assert req_obj3.request_id != ""
	uuid.UUID(req_obj3.request_id)
	# test None request
	setup_request_id(None, "request_id", True)

[daniel-sanche]

Can you add a better docstring?

[daniel-sanche]

Can we use a better name for this file? We already have api_core.gapic_v1.method, so api_core.gapic_v1.method_helpers seems confusing.

Would this fit in with the other helpers in api_core.gapic_v1.method? Or one of the other existing files? (method.py describes itself as "Helpers for wrapping low-level gRPC methods with common functionality". I can't remember if that's how this method is used)

If not, maybe we could call this api_core.gapic_v1.request, since it seems to be for building requests? Are other similar methods coming later, or is this a one-off?