Empty `.map` pipeline never completes

[fubuloubu]

I have a pipeline task that's like Pipeline(broker, produces_array).map(another_task) but it never completes when I want using task.wait_result if produces_array returns an empty list

[fubuloubu]

I think if you just bail here when len is 0, it would work:

taskiq-pipelines/taskiq_pipelines/steps/mapper.py

Lines 109 to 111 in ba056d7

	raise AbortPipeline("Result of the previous task is not iterable.")
	for item in return_value: