How to manage NODE_ENV while testing API routes

[ChristopherPAndrews]

I have been struggling to test my API routes. I finally found this discussion, which got me much closer and seems to make sense.

I made a local copy of some of the tools from the next-testing-utils as suggested. The process of invoking next build and then starting up the server seems to work. However, my code uses NODE_ENV to determine which database setup to use ('production', 'development', or 'test'). I am using jest, so the environment should be set to 'test', but when I run my tests it would try to access the production DB. When I logged process.env.NODE_ENV, it reported 'production'. After thinking I was going insane (logging process.env showed NODE_ENV='test'), I discovered that deep under the hood webpack is just swapping out the string process.env.NODE_ENV with 'production' in my code (which I confirmed by looking at the generated code).

I can work around this with an additional environment variable in my code, but I am wondering if anyone has any thoughts about how to do this more elegantly (in essence, how can I make "test" builds that don't claim to be production).