Should the Next config file be mandatory?

[dario-piotrowicz]

checkRunningInsideNextjsApp works based on the assumption that there must be a Next config file for the application:

opennextjs-aws/packages/open-next/src/build/helper.ts

Lines 491 to 494 in cfbc4fb

	logger.error(
	"Error: next.config.js not found. Please make sure you are running this command inside a Next.js app.",
	);
	process.exit(1);

If such a file does not exist this function forcefully terminates the process.

The issue is that I think that the Next config file is actually not mandatory, for example take the following starter from Vercel: https://vercel.com/templates/portfolio/portfolio-starter-kit (https://github.com/vercel/examples/tree/main/solutions/blog), there is no Next config file, but Next.js doesn't seem to be a problem.

Additionally in the Next.js docs there isn't a mention that the Next config file is mandatory, they say that "Next.js can be configured through a next.config.js file" (not that it needs to be).

So ideally OpenNext should also support applications without the Next config file?

Note: I suspect that the vast majority of Next.js applications do include a next config file (create-next-app does create one for you) so maybe this is not a huge concern, I figured I'd raise the question anyways

[khuezy]

Good point, we should match next's spec. How many places do we make this assumption?
At least here

I'd be surprised if there is a non-trivial app that doesn't use the next.config file.

[vicb]

Good point, we should match next's spec. How many places do we make this assumption? At least here

If that's the only place, it might be a new bug.
This code was introduced by @conico974 to fix a missing default in the config (bug in Next 16.0.0 to 16.0.3 IIRC) a few weeks ago

[conico974]

It's been used for a while here

opennextjs-aws/packages/open-next/src/build.ts

Line 51 in cfbc4fb

buildHelper.checkRunningInsideNextjsApp(options);

I guess if Next does support that we ideally should find another way to do that. But given that almost everyone will have one, it's probably enough to just add something in the docs

[khuezy]

imo that's fine too. I think Nextjs should require a next.config file since create-next-app generates one as Dario mentioned.