Warning about legacy package.json format in Svelte package

[benmccann]

Description

The following warning is being produced

4:57:38 PM [vite-plugin-svelte] WARNING: The following packages have a svelte field in their package.json but no exports condition for svelte.

@egjs/[email protected]

Please see https://github.com/sveltejs/vite-plugin-svelte/blob/main/docs/faq.md#missing-exports-condition for details.

This can be addressed by setting exports. The following fields can probably all be removed: svelte, main, module, es2015. Svelte packages should not be compiled with the Svelte compiler. However, they should be preprocessed to convert any TypeScript code to JavaScript code. This can be difficult to do manually. Svelte provide a svelte-package command to assist with this: https://kit.svelte.dev/docs/packaging. However, the .ts file here is very simple, so one solution would probably be to just rename it .js and remove the build step.

Changing the packaging in this way will be required to continue working with future versions of Svelte, but is a breaking change, so it should be done before a 4.0 release.

Steps to check or reproduce

Use in a Svelte project. E.g. checkout https://github.com/immich-app/immich, cd web, npm install, npm run build