How to test @app.on_event("shutdown") in FastAPI?

Question

I have a simple FastAPI setup as below,

# main.py

from fastapi import FastAPI

app = FastAPI()





@app.get("/")
def root():
    return {"message": "Hello World"}

How can I write (unit)test for this app_shutdown(...) functionality?

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Related Posts

• This SO post is also asking similar question, but, not in a "testing context"
• The official doc has something similar, but, there is no example for on_event("shutdown")

Answer 1

According to the documentation , you need to wrap it in the context manager (a with statement) to trigger the events, something like this:

def test_read_items():
    with TestClient(app) as client:
        response = client.get("/items/foo")
        assert response.status_code == 200

If you use pytest , you can set up a fixture for it like this:

from main import app
from fastapi.testclient import TestClient

import pytest


@pytest.fixture
def client():
    with TestClient(app) as c:
        yield c


def test_read_main(client):
    response = client.get("/")
    assert response.status_code == 200