async test is RuntimeError: no running event loop in router with await

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Example Code

from fastapi import FastAPI
import asyncio
import pytest
from httpx import AsyncClient


app = FastAPI()


async def query_db():
    await asyncio.sleep(0.1)    # add this, it's error
    return {'id': 1, 'data': 'hi'}


@app.get('/')
async def get_data():
    data = await query_db()
    return data


@pytest.mark.anyio
async def test_get_data():
    # async with AsyncClient(base_url='http://127.0.0.1:8000') as ac: # don't use `app=app`, need manual launch server, but it's ok.
    async with AsyncClient(app=app, base_url='http://127.0.0.1:8000') as ac:
        response = await ac.get('/')
    assert response.status_code == 200

Description

execute pytest in terminal it is raise RuntimeError: no running event loop.

in fact, it is RuntimeError: Event loop is closed in my project.

Operating System

Linux

Operating System Details

ubuntu20.04

FastAPI Version

0.72.0

Python Version

3.8.10

Additional Context

No response

[blokje]

This is not a FastAPI issue but is related to AnyIO. More information about testing with AnyIO can be found at https://anyio.readthedocs.io/en/stable/testing.html.

In this case you are missing an instruction on which backend to use for testing. By adding the following snippet to your code (copied from link above) your test will run:

@pytest.fixture
def anyio_backend():
    return 'asyncio'

[MartinSchere]

@CarlosLannister The base URL needs to be http://test:

@pytest.fixture(scope='function')
async def client():
    async with AsyncClient(app=app, base_url='http://test') as client:
        yield client