test_dependency_normal_exceptions.py

import pytest
from fastapi import Body, Depends, FastAPI, HTTPException
from fastapi.testclient import TestClient

initial_fake_database = {"rick": "Rick Sanchez"}

fake_database = initial_fake_database.copy()

initial_state = {"except": False, "finally": False}

state = initial_state.copy()

app = FastAPI()


async def get_database():
    temp_database = fake_database.copy()
    try:
        yield temp_database
        fake_database.update(temp_database)
    except HTTPException:
        state["except"] = True
        raise
    finally:
        state["finally"] = True


@app.put("/invalid-user/{user_id}")
def put_invalid_user(
    user_id: str, name: str = Body(), db: dict = Depends(get_database)
):
    db[user_id] = name
    raise HTTPException(status_code=400, detail="Invalid user")


@app.put("/user/{user_id}")
def put_user(user_id: str, name: str = Body(), db: dict = Depends(get_database)):
    db[user_id] = name
    return {"message": "OK"}


@pytest.fixture(autouse=True)
def reset_state_and_db():
    global fake_database
    global state
    fake_database = initial_fake_database.copy()
    state = initial_state.copy()


client = TestClient(app)


def test_dependency_gets_exception():
    assert state["except"] is False
    assert state["finally"] is False
    response = client.put("/invalid-user/rick", json="Morty")
    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "Invalid user"}
    assert state["except"] is True
    assert state["finally"] is True
    assert fake_database["rick"] == "Rick Sanchez"


def test_dependency_no_exception():
    assert state["except"] is False
    assert state["finally"] is False
    response = client.put("/user/rick", json="Morty")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "OK"}
    assert state["except"] is False
    assert state["finally"] is True
    assert fake_database["rick"] == "Morty"