[Docs] Lifespan ref implementation

Hi everyone. Looking at https://asgi.readthedocs.io/en/latest/specs/lifespan.html , I saw the following example implementation of the lifespan type.

        while True:
            message = await receive()
            if message['type'] == 'lifespan.startup':
                ... # Do some startup here!
                await send({'type': 'lifespan.startup.complete'})
            elif message['type'] == 'lifespan.shutdown':
                ... # Do some shutdown here!
                await send({'type': 'lifespan.shutdown.complete'})
                return

My naive implementation would consist of four flat lines of code only (receive, send, receive, send).

What is the reason for the while True loop and the fail-safe message handling here? It’s seems like I am missing something.

[andrewgodwin]

Oh, you’re right, sorry - the loop should be outside the if statement there. That does need fixing!

[srkunze]

I get the feeling, we might be talking past each other. This is the complete code example from the docs:

As I understand it, the highlighted loop (while True) is just for the lifespan protocol, which only contains two message types to be received and processed in this order.

So, my suggestion is the following:

async def app(scope, receive, send):
    if scope['type'] == 'lifespan':
        message = await receive()
        assert message['type'] == 'lifespan.startup'
        ... # Do some startup here!
        await send({'type': 'lifespan.startup.complete'})

        message = await receive()
        assert message['type'] == 'lifespan.shutdown'
        ... # Do some shutdown here!
        await send({'type': 'lifespan.shutdown.complete'})
    else:
        pass # Handle other types

Am I missing something here?