bug: Duplicate copy of _app on build

[jthegedus]

Describe the bug

A second copy of the _app dir is created under .svelte/output/client/ and then copied on build to the adapter output.

To Reproduce

Reproduction repo here - https://github.com/jthegedus/sveltekit-firebase-adapter-bug

Expected behavior

It does not create duplicate _app dirs.

[jthegedus]

This could be related - sveltejs/kit#587 🤔

[jthegedus]

Could be related - sveltejs/kit#861

[jthegedus]

It is sveltejs/kit#587

The adapter reads the user's firebase.json configuration file to identify which dir contains static assets to push to the Firebase CDN, in Firebase this defaults to public and is almost never changed by the user. This results in the following process:

• svelte-kit build outputs .svelte/output/client/_app/*
• Firebase adapter then executes copy_static_files and copy_client_files which copies the static and .svelte/output/client/_app/* dir contents to public
• on subsequent svelte-kit build executions Vite then copies public contents into .svelte/output/client/_app/*, then outputs the new build as well, resulting in .svelte/output/client/_app/* and .svelte/output/client/_app/_app/*. This then gets copied by the adapter copy_static_files and copy_client_files into public.
• each re-run of svelte-kit build produces a further nested _app dir in .svelte/output/client/ resulting in increasingly large uploads to the CDN

[jthegedus]

#39 included some documentation to notify users. A final soln in sveltejs/kit#587 would be ideal

[Nushio]

As of the latest sveltekit / sveltekit adapter firebase, we're no longer using a duplicate copy of _app.
I'll go ahead and close this issue.

[jthegedus]

Resolved in sveltejs/kit#4214

There is some code which should be removed to accompany this change. I will look to cover this in a rewrite soon.