chore: get rid of `__sveltekit/*` by Rich-Harris · Pull Request #16813 · sveltejs/kit

Rich-Harris · 2026-08-15T01:44:54Z

This PR gets rid of all the virtual modules, in favour of using real modules in .svelte-kit/generated.

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pkg-svelte-dev · 2026-08-15T01:44:57Z

Install the latest version of @sveltejs/kit from 5c31079:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/5c310793785ed8362c595295829c0625cb7d1030

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16813

changeset-bot · 2026-08-15T01:44:58Z

🦋 Changeset detected

Latest commit: 5c31079

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/kit	Patch

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svelte-docs-bot · 2026-08-15T01:47:58Z

Preview: https://svelte-dev-git-preview-kit-16813-svelte.vercel.app/

…odule path, so it never matches and is always `false`. This commit fixes the issue reported at packages/kit/src/exports/vite/index.js:1773 ## Bug In `packages/kit/src/exports/vite/plugins/env-vars.js`, this PR moved the generated env directory: ```js dir = posixify( path.resolve(c.root, config.outDir, `generated/${is_build ? 'build' : 'dev'}/env`) ); ``` So in build mode the client env module is written to `${out_dir}/generated/build/env/public/client.js`. But `packages/kit/src/exports/vite/index.js:1773` still looked up the pre-PR path: ```js chunk.modules[`${out_dir}/generated/env/public/client.js`] ``` `chunk.modules` keys are absolute module paths, and `out_dir === posixify(kit.outDir)` matches the base env-vars.js resolves against — so the only difference is the missing `build/` segment. This block runs during the client build (`is_build` is always true here, consistent with line 461 which uses `generated/${is_build ? 'build' : 'dev'}`), so the lookup can never match. ## Impact `uses_env_dynamic_public` becomes stuck at `false`. It is stored in `build_data.client` (lines ~1801 and ~1849) and controls whether the runtime prerendered public env module is loaded at runtime. Apps that import `$app/env/public` on the client **and** use dynamic (non-static) public env vars would silently get stale/missing runtime env values — a regression versus before this PR, where the path matched. ## Trigger Build an app that imports `$app/env/public` in client code with at least one `public && !static` env var configured. Previously the chunk-module lookup matched and `uses_env_dynamic_public` was `true`; now it always resolves `false`. ## Fix Updated the lookup to the new build-mode path: ```js chunk.modules[`${out_dir}/generated/build/env/public/client.js`] ``` Co-authored-by: Vercel <vercel[bot]@users.noreply.github.com> Co-authored-by: Rich-Harris <hello@rich-harris.dev>

…` instead of `generated/dev/`, so it never updates the module that is actually imported This commit fixes the issue reported at packages/kit/src/exports/vite/dev/index.js:457 ## Bug In `packages/kit/src/exports/vite/dev/index.js`, the `watcher.on('all', ...)` handler regenerates the server module when `app.html`, `error.html`, `service-worker`, or `hooks.server` change: ```js write_server(svelte_config, path.join(svelte_config.outDir, 'generated'), root); ``` This passes `<outDir>/generated` as the output directory. But in dev, every other part of the system uses `<outDir>/generated/dev`: * `sync.create(config, root, manifest_data, /* is_build */ false)` computes `output = path.join(config.outDir, 'generated/dev')` and calls `write_server(config, output, root)` (`sync.js:25-29`). * The Vite `<sveltekit:generated>` alias resolves to in dev (`exports/vite/index.js:455`). * The dev SSR entry imports from `generated/dev/client/...` (`dev/index.js:179,189`). So `write_server` from the watcher writes to `generated/server.js` and `generated/shared/error-template.js`, while the module actually imported at runtime lives at `generated/dev/server.js`. ## Trigger Editing `src/app.html`, `src/error.html`, `src/hooks.server.js`, or the service worker file during `vite dev`. The watcher fires and regenerates into the wrong directory, so the running server keeps serving the stale `generated/dev/server.js`. The change only takes effect after a full dev-server restart (which runs `sync.create` with the correct `generated/dev` path). ## Fix Pass `path.join(svelte_config.outDir, 'generated', 'dev')` so the watcher writes to the same location `sync.create(..., false)` writes to and that the alias imports from. Co-authored-by: Vercel <vercel[bot]@users.noreply.github.com> Co-authored-by: Rich-Harris <hello@rich-harris.dev>

teemingc

Nice! Added some small notes. Looking forward to more cleaning up of the vite/index.js file 😄

teemingc · 2026-08-18T15:48:30Z

-							...builder.environments.client.config.define,
-							...builder.environments.serviceWorker.config.define
-						};
+							...builder.environments.serviceWorker.config.define,


Just to note: Sapphi mentioned changing config options after the configResolved hook isn't recommended and isn't guaranteed to work in the future. That said, I filed vitejs/vite#22092 a while back and the recommendation was to use virtual modules in the meantime 😅 I think it's better if we break free from virtual modules though.

teemingc · 2026-08-18T15:55:46Z

-/** Internal version of $app/paths */
-declare module '__sveltekit/paths' {
-	export let base: '' | `/${string}`;
-	export let assets: '' | `https://${string}` | `http://${string}` | '/_svelte_kit_assets';
-	export let app_dir: string;
-	export let relative: boolean;
-	export function reset(): void;
-	export function override(paths: { base: string; assets: string }): void;
-	export function set_assets(path: string): void;
-}


As a follow-up, we should check if we can get rid of any mocks in packages/kit/vitest.kit.config.js and packages/kit/mocks. I think we can get rid of at least this __sveltekit/paths one.

Co-authored-by: Tee Ming <chewteeming01@gmail.com>

… more-generated-aliases

Rich-Harris added 2 commits August 14, 2026 21:22

use an alias instead of a resolveId hook

5d6c85d

WIP

9c16022

vercel Bot and others added 8 commits August 15, 2026 10:20

replace payload in service worker

bf63fd2

format

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use a define

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Merge branch 'generated-alias' into more-generated-aliases

68ff4bc

drive-by

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reduce indirection

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update comment

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Base automatically changed from generated-alias to version-3 August 17, 2026 22:23

Rich-Harris added 8 commits August 17, 2026 18:29

merge version-3

a38e4a1

fix merge

dfe66ba

fix

ba53e7c

get rid of __sveltekit/server

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unused

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more

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more

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oops

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vercel Bot reviewed Aug 18, 2026

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Comment thread packages/kit/src/exports/vite/dev/index.js Outdated

changeset

a3296b3

Rich-Harris force-pushed the more-generated-aliases branch from cc47fbb to a3296b3 Compare August 18, 2026 01:04

vercel Bot and others added 3 commits August 18, 2026 01:09

fix

d46ba5d

prevent race condition with dep scanning

2c62571

Rich-Harris mentioned this pull request Aug 18, 2026

chore: remove define merging #16819

Draft

unused

ab7fa01

teemingc linked an issue Aug 18, 2026 that may be closed by this pull request

Replace virtual modules with generated modules #15212

Closed

teemingc approved these changes Aug 18, 2026

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Rich-Harris and others added 4 commits August 18, 2026 12:06

these were accidentally removed

f9d1bc8

Update .changeset/shy-squids-film.md

f972dd5

Co-authored-by: Tee Ming <chewteeming01@gmail.com>

Merge branch 'more-generated-aliases' of github.com:sveltejs/kit into…

9d410b4

… more-generated-aliases

merge

5c31079

Rich-Harris merged commit c4d93e5 into version-3 Aug 18, 2026
25 of 26 checks passed

Rich-Harris deleted the more-generated-aliases branch August 18, 2026 16:33

Rich-Harris mentioned this pull request Aug 18, 2026

chore: remove some unused mocks #16841

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chore: get rid of `__sveltekit/*` - #16813

chore: get rid of `__sveltekit/*`#16813
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more-generated-aliases

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