[IzaakGough]

A Pub/Sub message that has attributes but no data crashed on_message_published with TypeError: Message.__init__() missing 1 required positional argument: 'data' before the handler ran.

This lets those messages through with data set to None, makes None the default for data when building a Message directly, and types publish_time as the datetime it already is.

• ordering_key is now str | None = None. The field after data needs a default too, and the handler already passed None when there is no ordering key.
• data is now typed str | None, so type checkers will flag code that passes msg.data straight to b64decode. .json returns None for both a missing and an empty payload, because the emulator sends "" for attribute-only messages.
• Draft refactor: replace datetime parsing with utility function for consistency across event handlers #274 removes the datetime import this annotation uses. Whichever PR lands second should keep it.

Tested with unit tests and in the emulator with an attribute-only message. Not tested with a real Pub/Sub delivery.

[gemini-code-assist]

Code Review

This pull request updates the Message class in pubsub_fn.py to change the type of publish_time to a timezone-aware datetime and allows data to be None when a Pub/Sub message is published without a payload. It also updates the message handler to default data to None and adds comprehensive unit tests to verify these behaviors. I have no feedback to provide as there are no review comments.

[CorieW]

LGTM

nits:

• data="" still makes .json raise, while data=None returns None. Should "" return None too, in case the emulator sends attribute-only messages that way?
• data: str | None may cause new mypy/pyright warnings for users (e.g. b64decode(msg.data)). Worth a changelog note?
• No test covers a present orderingKey (e.g. "abc" → ordering_key == "abc").
• The older tests could reuse _raw_event instead of building the CloudEvent by hand.