Route handlers are just API endpoints

I do like testing them with an E2E tools

but in Jest it's doable too, you can either call the function directly with mocked data

or run your server from Jest and test it

I plan to release a course on testing: https://course.nextjspatterns.com/testing-qa-react-server-components-a-next-js-pattern
I don't have examples yet though

@Eric Burel I opened an issue, am I missing something? The linked repo in the issue is about as barebones as it gets. https://github.com/vercel/next.js/issues/61520

It's a tad weird

you spin up an Express app

usually what we do in this case is that we call the API using the "app" object more directly

sorry I am a bit rusty but basically, you don't to run an actual HTTP request when doing that

you can use stuff like supertest

given your setup, why don't you run the actual Next.js app and then call to fetch?

also you don't mention the issue you face: error message, bug, test not running etc.?

this is how I've setup tests against an Express API lately: https://github.com/Devographics/Monorepo/blob/main/api/src/server.test.ts

Next.js codebase has a setup that runs the next app too but way more complex, you might take a look if you have sme spare time

the alternative is "just" calling your route handler by importing it

you don't need the Express server around it, it doesn't bring much value, given also that route handlers are not Node specific (say you want to test an edge route handler someday)