Feedback: using _app.mdx vs _app.tsx is weird and more error prone

[transitive-bullshit]

I got my use case working with _app.tsx, but after #1448, the guidance and console logs tell you to use _app.mdx.

This feels really weird to me as an end user. I tried using _app.mdx and kept running into weird transpilation issues, and all existing docs and examples from the greater Next.js ecosystem use _app.tsx.

For context, I'm not using mdx at all for https://sklearn.vercel.app (solely md).

My recommendation would be to find a way to have _app.tsx / _document.tsx be the default methods for injecting custom JS/TS.

[dimaMachina]

Please provide your reproduction of weird behavior with _app.mdx

[transitive-bullshit]

This is not a bug report; rather just general feedback.

As for a repro:

git clone git@github.com:transitive-bullshit/scikit-learn-ts.git
cd scikit-learn-ts
git checkout d3adcf4bccd8010d4edae6e7bc487d545f7c46ff # current HEAD
pnpm i
cd docs
pnpm build # builds fine with pages/_app.tsx
mv pages/_app.tsx pages/_app.mdx
pnpm build # obfuscated error with the mdx version

[dimaMachina]

You can't just declare variables (you must to use export /export default with declaration) in mdx files, take a look of a working example of how you need to export your App https://github.com/shuding/nextra/blob/main/docs/pages/_app.mdx

[transitive-bullshit]

Thanks @B2o5T. Removing the TS types from the mdx file makes the build work.

My original feedback still stands, however. I'd greatly prefer to use _app.tsx / _document.tsx for editor support / familiarity / tooling / existing code / typescript support / copying code from examples / etc.

Really appreciate the quick response btw – thanks for all your hard work! 🙏 💕

[dimaMachina]

We'll try to improve it in Nextra 3

[transitive-bullshit]

Thanks @B2o5T 🙏

[prisis]

One more point to allow _app.tsx would be for example https://github.com/dequelabs/axe-core with the current _app.mdx, i can not use it.