test(pubsub): add more publisher actor tests

[PhongChuong]

No description provided.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.02%. Comparing base (2259157) to head (1c3784a).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4581   +/-   ##
=======================================
  Coverage   95.02%   95.02%           
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  Files         195      195           
  Lines        7456     7456           
=======================================
  Hits         7085     7085           
  Misses        371      371           

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[dbolduc]

optional: This test doesn't really verify that the order the messages go in is the order they show up in the requests.

You could send the requests out on an unbounded_channel...

google-cloud-rust/src/pubsub/src/subscriber/session.rs

Lines 395 to 397 in 76753ba

	ack_tx
	.send(r.into_inner())
	.expect("sending on channel always succeeds");

and verify the requests contained [m1, m2], [m3, m4], ... , [m9, m10] at the end of the test:

google-cloud-rust/src/pubsub/src/subscriber/session.rs

Lines 422 to 425 in 76753ba

	// Verify the acks went through.
	let ack_req = ack_rx.try_recv()?;
	assert_eq!(ack_req.subscription, "projects/p/subscriptions/s");
	assert_eq!(sorted(ack_req.ack_ids), test_ids(1..7));

[PhongChuong]

Thanks. Let me think about how to do this cleanly for all sequential actor tests and add it in a future PR.