Next.js 13 support

[martpie]

• [x] What breaks?
• [x] Play with the new transpilePackages option
• [x] What can we remove from this plugin with transpilePackages
• [x] Support app/
• [ ] Check Turbopack

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About the next transpilePackages option:

• ✅ test-local-module (import and use local ES module)
• ✅ test-npm-module (import and use npm ES module)
• ❌ test-local-typescript-module (import a local module written in TypeScript)
• ❌ test-css-module (import local component importing a css module)
• ❌ test-scss-module (import local component importing a scss module)
• ❌ test-global-ccss (import local component import css to be injected globally)
• ❌ test-global-scss (import local component import scss to be injected globally)

TLDR: Transpiling classic modules is ok. Transpiling local TypeScript libraries or component using CSS does not work.

[martpie]

Quickly checked the new transpilePackages option, and it's not working on most of the use cases next-transpile-modules is trying to solve (css imports in dependencies especially).

Considering the feature is also experimental, I don't foresee next-transpile-modules dying anytime soon until those usecases are fixed at Next.js level, and/or a good alternative exists.

I will also open an issue on Next.js' side to explain those different usecases, and see what the team thinks about them.

edit: done, cf https://github.com/vercel/next.js/discussions/42136

[martpie]

noice 😎

I think we could do a first release without support for app-dir / turbopack. I'll quickly mess around with app-dir just in case.

[martpie]

👀