Testing a uvicorn server

[arunppsg]

I am trying to test a uvicorn server and I was following #1103 on setting up the testing ecosystem. This is my test_main.py

import tempfile
import requests
import pytest
import contextlib
import time
import threading
import uvicorn

PORT = 7000
HOST = '127.0.0.1'
BACKEND_URL = 'http://' + str(HOST) + ":" + str(PORT) + "/"


class Server(uvicorn.Server):
    def install_signal_handlers(self):
        pass

    @contextlib.contextmanager
    def run_in_thread(self):
        thread = threading.Thread(target=self.run)
        thread.start()
        try:
            while not self.started:
                time.sleep(1e-3)
            yield
        finally:
            self.should_exit = True
            thread.join()

config = uvicorn.Config("server:app", host=HOST, port=PORT, log_level="info")

@pytest.fixture(scope="session")
def setUp():
    server = uvicorn.Server(config=config)
    with server.run_in_thread():
      yield

def test_login():
    username = 'test'
    password = 'test'
    request = BACKEND_URL + f"login/?username={username}&password={password}"
    response = requests.put(request)
    assert response.status_code == 200

whereas my server.py looks like this:

from fastapi import FastAPI

app = FastAPI()

@app.put("/login")
async def login(username: str, password: str)
    return {"status": True}

When I run pytest test_main.py, I get the error

  File "/Users/arun/miniconda3/envs/chiron/lib/python3.9/site-packages/requests/sessions.py", line 529, in request
    resp = self.send(prep, **send_kwargs)
  File "/Users/arun/miniconda3/envs/chiron/lib/python3.9/site-packages/requests/sessions.py", line 645, in send
    r = adapter.send(request, **kwargs)
  File "/Users/arun/miniconda3/envs/chiron/lib/python3.9/site-packages/requests/adapters.py", line 519, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='127.0.0.1', port=7000): Max retries exceeded with url: /login/?username=test&password=test (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7fbbf91e2070>: Failed to establish a new connection: [Errno 61] Connection refused'))

I am not sure whether this is the best way to run tests for uvicorn or is there some other method to test uvicorn server?

[euri10]

if you want to test your endpoints you have several options:

1. use the Starlette built-in TestClient, the FastAPI docs should give you plenty of examples
2. use httpx as a test client, see https://www.python-httpx.org/async/#calling-into-python-web-apps

if you really want to run uvicorn during your tests, which you probably dont most of the time, you can either run it in a thread like you did or look at our test suite here

uvicorn/tests/utils.py

Lines 9 to 18 in b8e65e4

	@asynccontextmanager
	async def run_server(config: Config, sockets=None):
	server = Server(config=config)
	cancel_handle = asyncio.ensure_future(server.serve(sockets=sockets))
	await asyncio.sleep(0.1)
	try:
	yield server
	finally:
	await server.shutdown()
	cancel_handle.cancel()

and take inspiration of it

[arunppsg]

Hey, thanks for your response! It saved me a good amount of time.