Most API testing tutorials test a single endpoint in isolation. Real systems are messier: services call each other over HTTP, share JWT tokens, and fail in ways that only show up when the whole thing runs together.
This article takes a different approach. We will build a small but realistic microservices system — user-service, product-service, and order-service — and then write a complete test suite for it using two different frameworks: Jest + Supertest on the Node.js side and Pytest + HTTPX on the Python side. Every code snippet in this article lives in a working repository at github.com/andre-carbajal/api-testing-microservices.
The system we are testing
Before writing a single test, it helps to understand what we are dealing with.
┌──────────────┐ JWT auth ┌────────────────┐
