The latest articles on DEV Community by Vivek G Sindagi (@itsviv0). https://dev.to/itsviv0 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3302104%2F77ed93f3-b830-49ef-aa81-b7d09c777449.jpeg https://dev.to/itsviv0 en Vivek G Sindagi Sat, 28 Jun 2025 05:19:48 +0000 https://dev.to/itsviv0/building-and-testing-my-first-api-project-with-express-supabase-and-keploy-8km https://dev.to/itsviv0/building-and-testing-my-first-api-project-with-express-supabase-and-keploy-8km <p>I had never developed and implemented a complete backend project until recently. I had occasionally written little Express.js scripts, but nothing that required building APIs, linking them to an actual database, putting them into use, and writing tests.</p> <p>"Build and host a real backend API with a live PostgreSQL database — and test it properly" was the challenge I set for myself.</p> <p>Warning: I succeeded. And without writing a single test by hand, I was able to achieve 100% test coverage with the help of a tool called Keploy.</p> <p>This is what I discovered.</p> <h2> 🚧 Starting from Zero: My Stack </h2> <p>I wanted to build something simple but complete. So I created a Notes API — where users can create, read, update, and delete notes. Here's what I used:</p> <ul> <li>Express.js – To build RESTful API endpoints</li> <li>Supabase – As my PostgreSQL database in the cloud</li> <li>Vercel – To deploy my backend serverless functions</li> <li>Keploy – To auto-generate tests for my API</li> </ul> <p>I named the project express-supabase-api, and hosted it on my subdomain:<br> 🔗 <a href="https://express-supabase-api.vivs.live/api/notes" rel="noopener noreferrer">https://express-supabase-api.vivs.live/api/notes</a></p> <h2> 🤦‍♂️ The Testing Roadblock </h2> <p>At first, I tried writing tests manually with Jest and Supertest. It worked… sort of.</p> <p>But I ran into issues:</p> <ul> <li>How do I mock Supabase without messing up my real database?</li> <li>How do I avoid inserting and deleting real data on every test run?</li> <li>I kept rewriting boilerplate just to test basic routes</li> </ul> <p>As a beginner, it felt like I was spending more time writing test cases than writing actual logic.</p> <h2> 🤖 Discovering Keploy (and Getting 100% Coverage Instantly) </h2> <p>Here's what I did:</p> <ol> <li>Ran my API on vercel</li> <li>Installed Keploy using their one-liner installer</li> <li>Used my API like a normal user (created a note, updated one, deleted another)</li> <li>Keploy captured all the traffic</li> <li>Boom — it generated test cases based on those real interactions</li> </ol> <h2> 🙌 Final Thoughts: Every Beginner Should Try This </h2> <p>If you’re building your first real backend project like I was — especially with Node.js and Express — I highly recommend trying Keploy.</p> <p>It doesn’t replace manual testing forever, but it gives you a huge head start and teaches you the value of testing without overwhelming you with complexity.</p> <p>🔗 Check out my API here: <a href="https://express-supabase-api.vivs.live/api/notes" rel="noopener noreferrer">https://express-supabase-api.vivs.live/api/notes</a><br> 📦 Repo: <a href="https://github.com/itsviv0/express-supabase-api" rel="noopener noreferrer">https://github.com/itsviv0/express-supabase-api</a></p>