Testing path operations in FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of testing path operations in FastAPI?

Testing path operations ensures that your API endpoints work correctly by simulating requests and checking responses without running the full server.

beginner

Which FastAPI tool is commonly used to test path operations?

The TestClient from fastapi.testclient is used to simulate HTTP requests to your API endpoints during tests.

intermediate

How do you test a GET request to a path operation using TestClient?

You create a TestClient instance with your FastAPI app, then call client.get('/path') and check the response status code and data.

intermediate

Why is it important to test both status codes and response content in path operation tests?

Checking status codes ensures the API responds correctly (like 200 or 404), and checking content verifies the data returned is correct and complete.

intermediate

What is a common way to test POST requests with JSON payloads in FastAPI path operations?

Use TestClient's client.post method with json parameter to send data, then verify the response status and returned JSON data.

Which FastAPI class helps simulate HTTP requests for testing?

A FastAPITest

B RequestSimulator

C TestClient

D HttpTester

TestClient is the official FastAPI tool to simulate HTTP requests in tests.

What method would you use to test a GET request to '/items/1'?

A client.post('/items/1')

B client.get('/items/1')

C client.put('/items/1')

D client.delete('/items/1')

GET requests are tested using client.get with the path as argument.

When testing a POST request with JSON data, which parameter do you use in TestClient?

A json

B data

C body

D payload

The json parameter sends JSON data in the POST request body.

Why should you check the response status code in path operation tests?

A To confirm the API responded as expected (e.g., 200 OK)

B To check the server's CPU usage

C To verify the database connection

D To measure network speed

Status codes indicate if the request was successful or if errors occurred.

Which library is commonly used alongside FastAPI for writing tests?

A selenium

B unittest

C nose

D pytest

pytest is popular for writing and running tests with FastAPI.

Explain how to write a test for a FastAPI GET path operation using TestClient.

Think about simulating a browser or app request and checking what comes back.

Describe why testing both status codes and response data is important in FastAPI path operation tests.

Consider what would happen if only one was tested.