Combine python asyncio with pyee Event Emitter

Question

I am trying use the AsyncIOEventEmitter from the pyee library without success. For some reason the emitted event "Hi" never reaches the async_handler to complete the asyncio future. I also did not find proper examples online. Additionally I tried providing the current event and using a new event loop for the AsyncIOEventEmitter , but both yields the same result.

Can someone help me out? Example unit test below:

import asyncio
import logging
import pytest
from pyee import AsyncIOEventEmitter

LOG = logging.getLogger(__name__)

@pytest.mark.asyncio
async def test_setup(event_loop):
    LOG.info("1 - start")
    event_emitter = AsyncIOEventEmitter(asyncio.new_event_loop())

    # Create a new Future object.
    future_result = event_loop.create_future()
    LOG.info("2 - emit event")
    event_emitter.emit("event", "Hi")

    @event_emitter.on("event")
    async def async_handler(message):
        LOG.info(">>> %s", message)
        future_result.set_result(message)
        return future_result

    # Wait until *future_result* has a result and print it.
    LOG.info(await future_result)

Thanks!

Answer 1

ok figured it out, the async_handler method must be defined earlier in the test...

This worked now:

"""Event emitter playground"""
import asyncio
import logging
import pytest
from pyee import AsyncIOEventEmitter

LOG = logging.getLogger(__name__)


@pytest.mark.asyncio
async def test_setup(event_loop):
    """Receive event from emitter and complete future!"""
    LOG.info("1 - start")
    event_emitter = AsyncIOEventEmitter(asyncio.new_event_loop())

    @event_emitter.on("event")
    def async_handler(message):
        LOG.info(">>> %s", message)
        future_result.set_result(message)

    future_result = event_loop.create_future()
    LOG.info("2 - emit event")
    event_emitter.emit("event", "Hi")

    LOG.info(await future_result)