Missing async iterator in FakeAIOKafkaConsumer

[AMelacini]

In order to be aligned with AIOKafkaConsumer, it would be nice to able to do:

consumer = FakeAIOKafkaConsumer()

# ... some code ...

async for msg in consumer:
    do_process(msg)

This should be the pseudocode of all we need in file mockafka/aiokafka/aiokafka_consumer.py

class FakeAIOKafkaConsumer:
    # ....
    def __aiter__(self):
        return self

    async def __anext__(self):
        msg = await self.getone(...)
        if msg is not None:
            return msg

        # not sure we need to worry about  raise StopAsyncIteration

Just a thought...

[PeterJCLaw]

@AMelacini do you have any thoughts about what should happen when the consumer runs out of messages? Under aiokafka that would block indefinitely here, however in tests that seems less likely to be desirable.

On option I can see would be to raise StopAsyncIteration, perhaps with a warning. Alternatively we could raise a custom error indicating that the consumer has run out of messages. (Note that this does somewhat end up being the same as #117)

[AMelacini]

@PeterJCLaw I completely missed your messages, apologies for the silence.
I see your PR, ASAP I will fetch the branch and try it out...
Stay tuned

[AMelacini]

The PR looks reasonable given the discussion #117

I checked the test coverage and only one line is not covered by the unit test (which is pretty important, I can see)

`

def __aiter__(self):
    if self._is_closed:
        raise ConsumerStoppedError()  # << not covered by unit tests
    return self

`

basically the consumer already closed when __iter__ kicks in

Any chance that this PR can be approved merge @alm0ra?

I'm ready to help, if needed

[PeterJCLaw]

Thanks for the review! 94f761c addresses the coverage :)

[AMelacini]

I can confirm that all new lines of code added by this PR are covered by the test suite - fingers crossed for a merge into main