I have an REST-API app written with Uvicorn+FastAPI
Which I want to test using PyTest.
I want to start the server in a fixture when I start the tests, so when the test complete, the fixture will kill the app.
FastAPI Testing shows how to test the API app,
from fastapi import FastAPI
from starlette.testclient import TestClient
app = FastAPI()
@app.get("/")
async def read_main():
return {"msg": "Hello World"}
client = TestClient(app)
def test_read_main():
response = client.get("/")
assert response.status_code == 200
assert response.json() == {"msg": "Hello World"}
This doesn't bring the server online in the usual way. It seems that the specific functionality that is triggered by the client.get command is the only thing that runs.
I found these additional resources, but I can't make them work for me:
https://medium.com/@hmajid2301/pytest-with-background-thread-fixtures-f0dc34ee3c46
How to run server as fixture for py.test
How would you run the Uvicorn+FastAPI app from PyTest, so it goes up and down with the tests?
Inspired from @Gabriel C answer. A fully object oriented and async approach (using the excellent asynctest framework).
import logging
from fastapi import FastAPI
class App:
""" Core application to test. """
def __init__(self):
self.api = FastAPI()
# register endpoints
self.api.get("/")(self.read_root)
self.api.on_event("shutdown")(self.close)
async def close(self):
""" Gracefull shutdown. """
logging.warning("Shutting down the app.")
async def read_root(self):
""" Read the root. """
return {"Hello": "World"}
""" Testing part."""
from multiprocessing import Process
import asynctest
import asyncio
import aiohttp
import uvicorn
class TestApp(asynctest.TestCase):
""" Test the app class. """
async def setUp(self):
""" Bring server up. """
app = App()
self.proc = Process(target=uvicorn.run,
args=(app.api,),
kwargs={
"host": "127.0.0.1",
"port": 5000,
"log_level": "info"},
daemon=True)
self.proc.start()
await asyncio.sleep(0.1) # time for the server to start
async def tearDown(self):
""" Shutdown the app. """
self.proc.terminate()
async def test_read_root(self):
""" Fetch an endpoint from the app. """
async with aiohttp.ClientSession() as session:
async with session.get("http://127.0.0.1:5000/") as resp:
data = await resp.json()
self.assertEqual(data, {"Hello": "World"})