Writing tests for REST API endpoints

All the tools we need to test our FastAPI application are now ready. All these tests boil down to performing an HTTP request and checking the response to see if it corresponds to what we expect.

Let's start simple with a test for our hello_world path operation function. You can see it in the following code:

chapter9_app_test.py

@pytest.mark.asyncio
async def test_hello_world(test_client: httpx.AsyncClient):
    response = await test_client.get("/")
    assert response.status_code == status.HTTP_200_OK
    json = response.json()
    assert json == {"hello": "world"}

https://github.com/PacktPublishing/Building-Data-Science-Applications-with-FastAPI/blob/main/chapter9/chapter9_app_test.py

First of all, notice that the test function is defined as async. As we mentioned previously, to make it work with pytest, we had to install...