pytest RuntimeError: Event loop is closed FastApi - pytest

Question

I receive an error RuntimeError: Event loop is closed each time when i try to make more than one async call function inside my test. I already tried to use all suggestions on stackoverflow to rewrite event_loop fixture but nothing works. I wonder what i'm missing
Run test command: python -m pytest tests/ --asyncio-mode=auto
requirements.txt
pytest==7.1.2
pytest-asyncio==0.18.3
pytest-html==3.1.1
pytest-metadata==2.0.1
test.py
async def test_user(test_client_fast_api):
assert 200 == 200
request_first = test_client_fast_api.post( # works fine
"/first_route",
)
request_second = test_client_fast_api.post( # recieve RuntimeError: Event loop is closed
"/second_route",
)
conftest.py
#pytest.fixture()
def event_loop():
try:
loop = asyncio.get_running_loop()
except RuntimeError:
loop = asyncio.new_event_loop()
yield loop
loop.close()

Answer 1

It took me all afternoon to solve this problem.
I also try to succeed from other people's code, here is my code.
Add a file conftest.py to the directory where the test script is placed.
And write the following code.
import pytest
from main import app
from httpx import AsyncClient
#pytest.fixture(scope="session")
def anyio_backend():
return "asyncio"
#pytest.fixture(scope="session")
async def client():
async with AsyncClient(app=app, base_url="http://test") as client:
print("Client is ready")
yield client
And then write a test script test_xxx.py.
import pytest
from httpx import AsyncClient
#pytest.mark.anyio
async def test_run_not_exists_schedule(client: AsyncClient):
response = await client.get("/schedule/list")
assert response.status_code == 200
schedules = response.json()["data"]["schedules"]
schedules_exists = [i["id"] for i in schedules]
not_exists_id = max(schedules_exists) + 1
request_body = {"id": not_exists_id}
response = await client.put("/schedule/run_cycle", data=request_body)
assert response.status_code != 200
#pytest.mark.anyio
async def test_run_adfasdfw(client: AsyncClient):
response = await client.get("/schedule/list")
assert response.status_code == 200
schedules = response.json()["data"]["schedules"]
schedules_exists = [i["id"] for i in schedules]
not_exists_id = max(schedules_exists) + 1
request_body = {"id": not_exists_id}
response = await client.put("/schedule/run_cycle", data=request_body)
assert response.status_code != 200
This is the real test code for my own project. You can change it to your own.Finally, run in the project's terminal python -m pytest.If all goes well, it should be ok's.This may involve libraries that need to be installed.
pytest
httpx

Answer 2

Yeah wow I had a similar afternoon to your experience #Bai Jinge
This is the event loop fixture and TestClient pattern that worked for me:
from asyncio import get_event_loop
from unittest import TestCase
from async_asgi_testclient import TestClient
#pytest.fixture(scope="module")
def event_loop():
loop = get_event_loop()
yield loop
#pytest.mark.asyncio
async def test_example_test_case(self):
async with TestClient(app) as async_client:
response = await async_client.get(
"/api/v1/example",
query_string={"example": "param"},
)
assert response.status_code == HTTP_200_OK
Ref to relevant GitHub issue: https://github.com/tiangolo/fastapi/issues/2006#issuecomment-689611040
Please note - I could NOT figure our how to use Class based tests. Neither unittest.TestCase or asynctest.case.TestCase would work for me. pytest-asyncio docs (here) state that:
Test classes subclassing the standard unittest library are not supported, users are recommended to use unittest.IsolatedAsyncioTestCase or an async framework such as asynctest.