Abort async test if event loop catched unhandled exception

[HMaker]

Hi. Sometimes async tests hangs when background tasks raises some exception but it's not propagated to test function, it's not a bug in pytest-asyncio but a problem in application code. Can the following patch be used to abort current test if some exception is raised in background?

import inspect as _inspect
import asyncio as _asyncio
from functools import wraps as _wraps
from pytest_asyncio import plugin as _pytestasyncio_plugin

def _wrap_in_sync(func, _loop):
    """Return a sync wrapper around an async function executing it in the
    current event loop."""
    @_wraps(func)
    def inner(**kwargs):
        coro = func(**kwargs)
        if coro is not None:
            def forward_exception(loop, context):
                if _inspect.getcoroutinestate(coro) != _inspect.CORO_CLOSED:
                    coro.throw(context['exception'] if 'exception' in context else Exception(context['message']))
                else:
                    loop.default_exception_handler(context)
            _loop.set_exception_handler(forward_exception)
            task = _asyncio.ensure_future(coro, loop=_loop)
            try:
                _loop.run_until_complete(task)
            except BaseException:
                # run_until_complete doesn't get the result from exceptions
                # that are not subclasses of `Exception`. Consume all
                # exceptions to prevent asyncio's warning from logging.
                if task.done() and not task.cancelled():
                    task.exception()
                raise
    return inner
_pytestasyncio_plugin.wrap_in_sync = _wrap_in_sync

[seifertm]

My understanding is that you want exceptions in (background) tasks to raise an error rather than letting the test succeed silently.

In this case, I'll close this issue as a duplicate of #205.

Feel free to comment or reopen, if I misunderstood your intention.