Deprecate svelte field in package.json

[benmccann]

The svelte field was originally intended to allow package authors to be able to provide uncompiled .svelte files as well as a compiled .js version. We have decided if packages would like to provide a compiled version that a better way to do this is to create sub-package such as compiled.

The way the svelte field is currently implemented in vite-plugin-svelte breaks Vite's dependency optimization and we've decided removing support for the svelte field is the best path forward

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Latest commit: 099dd34

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

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@sveltejs/package	Patch

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[dummdidumm]

If we do that we need to make sure the rollup and webpack plugins still work correctly. How can we ensure that?

[benmccann]

The svelte field is optional in both plugins today

Here's a test showing that the Rollup plugin works without the svelte field: https://github.com/sveltejs/rollup-plugin-svelte/blob/master/test/node_modules/esm-no-pkg-export/package.json

Here's some documentation showing which fields svelte-loader resolves in order: https://github.com/sveltejs/svelte-loader#usage

vite-plugin-svelte does more complicated stuff with the field, but I believe that functionality is just an optimization and can be removed. I sent sveltejs/vite-plugin-svelte#483 for that

[dominikg]

related sveltejs/vite-plugin-svelte#482

That fixes the situation mostly with vps, but i'm still testing it. Perf can be a problem and also what happens with ssr.optimizeDeps.

[dominikg]

The svelte field is optional in both plugins today

Here's a test showing that the Rollup plugin works without the svelte field: https://github.com/sveltejs/rollup-plugin-svelte/blob/master/test/node_modules/esm-no-pkg-export/package.json

there are no .svelte files in that test directory, sure that's testing svelte resolve? i think it may just be fore the package.json export warning.

[benmccann]

there are no .svelte files in that test directory, sure that's testing svelte resolve?

You're right. It wasn't testing it. However, it does work. I just made a sample Rollup project using a node module with the following package.json to confirm:

{
	"main": "./src/Component.svelte"
}