How do I test batch processing using the TestBroker

[DLukeNelson]

@Lancetnik

I have a subscriber set up using batch=True, but I can't figure out how to publish multiple messages to it at once so that I can test my code against batches. (confluent kafka, if its relevant)

# tests.py
# Attempt 1:
await test_broker.publish(msg1, topic=MY_TOPIC)
await test_broker.publish(msg2, topic=MY_TOPIC)
# Consumer was invoked twice, each time with a list[Message] of length 1

# Attempt 2:
await test_broker.publish([msg1, msg2], topic=MY_TOPIC)
# Consumer was invoked once, with a list[list[Message]]

How can my tests correctly publish multiple messages to prove my batch handling works?

[DLukeNelson]

Almost immediately after posting this question, I had a realization: "Surely this case was tested somewhere within faststream."
So I searched within the faststream tests and came across:

# Attempt 3:
await test_broker.publish_batch(msg1, msg2, topic=MY_TOPIC)
# Works as expected, consumer was invoked once with a list[Message] of length 2