Overview

This is a reproduce-repo for a bug within NextJS API routes.
The bug is essentially a big difference between the DEV environment and the PROD environment in NextJS.
When only a GET and PUT handlers are defined for a given API route, only the GET handler will work in a PROD environment.

Steps to reproduce

1. Clone this repo (or create an app using create-next-app with all default options)
2. Create a route.ts file in src/app/api/anything
3. Make 2 functions for handling the PUT and GET methods
4. Run npm run dev and curl -X PUT http://localhost:3000/api/test to make sure it doesn't produce an error
5. Close the dev server
6. Run npm run build && npm run start to start the optimized server.
7. Perform the same curl request using curl -X PUT http://localhost:3000/api/test
8. The server returns an HTML page about a 405 error.

Expected behavior

The change in environment shouldn't affect the behavior of API routes.

Credits

Credits to Gede Dewo Wahyu M.W for discovering this here