How do multiple filtered subscriber behave?

[febus982]

I have a topic/channel for a resource that contains multiple message types and schemas. (i.e. books topic => book.created and book.borrowed events)

I want to make sure the message ordering is handled correctly (no borrowed events handled before created ones). Can I create 2 handlers in this way or the subscribers will proceed independently from each other?

@subscriber(
    filter=lambda msg: msg.type == "book.created",
)
async def handle_cerated(msg: BookCreated):
    ...

@subscriber(
    filter=lambda msg: msg.type == "book.borrowed",
)
async def handle_cerated(msg: BookBorrowed):
    ...

[Lancetnik]

Filter logic just allows you to call different handler functions for one message consumption
It is litterally the single subscriber, that iterates over your handlers and tries to find the first suitable one: https://github.com/airtai/faststream/blob/main/faststream/broker/subscriber/usecase.py#L335