[docs] add note to docs "`_app` cannot be overwritten"

[gabrielromk]

During the migration of the company handbook to the Netzo framework, I faced challenges with the application layout. Despite having all the necessary files installed, including netzo.ts, .env, etc., none of the functionalities were working as expected. After thorough investigation, I identified the problem to be associated with conflicting middleware in the _app.ts file. This middleware was overriding all Netzo configurations. Upon removing the conflicting middleware, Netzo became operational, resolving the issues encountered during the migration process.

with _app.ts

without _app.tsx

[miguelrk]

Good catch. Indeed, the netzo layout plugin injects a default _app.tsx so user can no longer use a custom _app.tsx without running into issues. This is due to how fresh works, and if a solution comes, it should come upstream from fresh. Be reminded that you can always use _layout.tsx files (one per file level) which will render under the auto-injected _app.tsx.

Keeping this open for now, so that we can add a note to the docs and avoid confusion for users.

[deer]

Hola chicos, I contribute a lot to fresh, specifically around plugins. What sort of solution are you looking for here? I don't see an easy way of combing an _app.tsx file from a plugin (or even from multiple plugins!) with one from the user's code. If you could elaborate on what you're looking for, that would be great.

[miguelrk]

Hola @deer! Thanks for your interest!

I agree, there might be no natural way of combining plugin-injected and user-defined _app files, and that's ok. Regarding this, I would prefer the current behavior of max 1 _app file, whether injected or not, in favor of simplifying the mental model when using fresh. That being said, adding a warning whenever fresh detects the presence of 2 or more _app files (from plugins and/or from user code) would be great. Same goes for _layout files, with the difference these are scoped at the route-level, rather than global like _app.

[deer]

Ok, it seems like the right solution is to dust off https://github.com/denoland/fresh/pull/1568 and finally get that merged. I'll keep any discussions of implementation details there (or more likely in the new PR that I might open), but I guess this would solve your problem.

[miguelrk]

Thanks for the pointer! Wasn't aware of https://github.com/denoland/fresh/pull/1568, that covers not only this warning but many more! That's great news. Let's keep the discussion over there 👍🏼

[miguelrk]

Closing as netzo no longer auto-injects an _app file via plugin in favor of explicitly having an _app.tsx in the template. So this issue has been solved.