feat: add support for read in edge environments by vnphanquang · Pull Request #13859 · sveltejs/kit

vnphanquang · 2025-06-05T05:55:35Z

This PR helps with the cloudflare part of #12446. Added a test case and I also tested in a project bootstrapped with create cloudflare@latest. Hope i didn't miss anything 🤞.

Thanks all.

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Latest commit: 3f0328e

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

This PR includes changesets to release 4 packages

Name	Type
@sveltejs/adapter-netlify	Minor
@sveltejs/adapter-vercel	Minor
@sveltejs/adapter-cloudflare	Minor
@sveltejs/kit	Minor

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svelte-docs-bot · 2025-06-05T05:56:02Z

Preview: https://svelte-dev-git-preview-kit-13859-svelte.vercel.app/

vnphanquang · 2025-06-05T06:09:50Z

Not sure why that particular firefox CI test failed but it did pass on my local machine (pnpm test:cross-platform:build). Let me know, thanks!

teemingc · 2025-06-06T01:23:25Z

Thanks for this PR! Is there any chance you could continue the work from #11674 so that it's implemented in the Netlify and Vercel adapters too? I think if the reusable fetchFile function could allow passing a fetch function to it, we could pass env.ASSETS.fetch in the case of the Cloudflare adapter and it would just work.

Not sure why that particular firefox CI test failed but it did pass on my local machine (pnpm test:cross-platform:build). Let me know, thanks!

I re-ran the test in CI and it passes. Probably just a flaky test that failed.

vnphanquang · 2025-06-06T01:50:38Z

Ah yes. Sorry I missed Rich's PR in my search. Will look into it. Thanks for the input!

vnphanquang · 2025-06-06T06:36:28Z

@eltigerchino extracted into a streamFileContent function via 6da55ed. A couple of things:

added some unit tests; I don't think they are strictly necessary but nice to have anyway,
exported this util via @sveltejs/kit/adapter, as I think kit is already a peer-dependency for all adapters anyway,
settled with this name rather than fetchFile since I feel like fetch would indicate a returned Response.

Also, I haven't added read for netlify & vercel yet, since edge environment can't be easily tested locally for them as far as I know (vercel requires connecting to a cloud project, and netlify docs says edge functions don't work locally).

I can spawn up some projects in netlify & vercel and do some manual tests, but I feel like i shouldn't block progress here. How about I do that in a separate PR?

Thanks

…t util for server read

teemingc · 2025-06-06T06:48:36Z

Thank you!

Also, I haven't added read for netlify & vercel yet, since edge environment can't be easily tested locally for them as far as I know (vercel requires connecting to a cloud project, and netlify docs says edge functions don't work locally).

I can spawn up some projects in netlify & vercel and do some manual tests, but I feel like i shouldn't block progress here. How about I do that in a separate PR?

Yeah, manual testing for those are fine. There is no local environment for Vercel and like you said, Netlify's edge doesn't work locally.

vladshcherbin · 2025-06-23T10:41:04Z

Can this be prioritized? It's very cumbersome to use static assets with Cloudflare with unexpected outcome. Vercel and other can be added later

…ementation

dummdidumm

@eltigerchino I found a solution that avoids adding a new export: tweak SvelteKit's read implementation to handle async values. Could you take another look?

(all SvelteKit tests fail currently but it was the only solution to make the adapter tests succed with the checks; annoying interim failures, which is why we should merge and release this in one go)

dummdidumm · 2025-07-15T16:15:55Z

+      ]
+    }
+  }
+}


Does Netlify require this or why do we have a deno.lock here? (same for the other test)

This is a build artifact from running the app with the Netlify CLI. I think it does another bundle at that point. I'll add it to to the .gitignore

teemingc · 2025-07-16T03:01:36Z

@eltigerchino I found a solution that avoids adding a new export: tweak SvelteKit's read implementation to handle async values. Could you take another look?

Thanks! That's a really nice solution.

benmccann · 2025-07-24T17:29:51Z

I'm happy we have tests for the Netlify adapter now. However, adding netlify-cli pulls in almost 1,000 dependencies into the project: http://npmgraph.js.org/?q=netlify-cli. Is there some way we can serve the built files without netlify-cli? With all the recent supply chain attacks going on, I don't love the idea of having all these extra dependencies...

dummdidumm · 2025-07-24T18:38:35Z

I think eventually we wanna turn these into "deploy to prod, do playwright stuff against prod url" tests. Slower but more reliable and fully replicates the environment

benmccann · 2025-07-24T23:48:05Z

In the meantime I wonder if we could just invoke sirv since the only thing we do is call netlify serve. I'm not sure what all netlify serve does and it's probably not exactly the same, but it would be a lot lighter.

teemingc · 2025-07-25T03:03:28Z

In the meantime I wonder if we could just invoke sirv since the only thing we do is call netlify serve. I'm not sure what all netlify serve does and it's probably not exactly the same, but it would be a lot lighter.

I'm not sure how sirv would work with the Netlify build output. At least in #12296 the CLI's serve is important for testing the split functions functionality with the Netlify middleware.

The Environment API integration is still far off, otherwise we could use the Netlify Vite plugin instead. I think Simon's idea might be a lot better and something we can implement sooner.

cc: @serhalp

benmccann · 2025-08-06T16:53:14Z

I shared another idea here: e18e/ecosystem-issues#156 (comment)

closes sveltejs#12446 closes sveltejs#11674 --------- Co-authored-by: Chew Tee Ming <chew.tee.ming@nindatech.com> Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>

#15161 fixed a cold-start race in adapter-cloudflare, where a concurrent second request could reach `server.respond` before `server.init` finished. The pattern came from #13859 in all three edge adapters, but only cloudflare got the fix. This applies the same change to the Vercel and Netlify edge entries. --- ### Please don't delete this checklist! Before submitting the PR, please make sure you do the following: - [x] It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs - [x] This message body should clearly illustrate what problems it solves. - [ ] Ideally, include a test that fails without this PR but passes with it. ### Tests - [x] Run the tests with `pnpm test` and lint the project with `pnpm lint` and `pnpm check` ### Changesets - [x] If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running `pnpm changeset` and following the prompts. Changesets that add features should be `minor` and those that fix bugs should be `patch`. Please prefix changeset messages with `feat:`, `fix:`, or `chore:`. ### Edits - [x] Please ensure that 'Allow edits from maintainers' is checked. PRs without this option may be closed.

feat: add support for server read in cloudflare adapter

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teemingc added the pkg:adapter-cloudflare label Jun 6, 2025

teemingc reviewed Jun 6, 2025

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Comment thread packages/adapter-cloudflare/test/apps/goose.jpg Outdated

fix: use txt instead of jpg for read test in cloudflare adapter

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vnphanquang force-pushed the 12446 branch 2 times, most recently from dc18769 to 6da55ed Compare June 6, 2025 06:20

vnphanquang requested a review from teemingc June 6, 2025 06:36

refactor: extract reusable ('@sveltejs/kit/adapter').streamFileConten…

de885af

…t util for server read

vnphanquang force-pushed the 12446 branch from 6da55ed to de885af Compare June 6, 2025 06:42

teemingc changed the title ~~feat: add support for server read in cloudflare adapter~~ feat: add support for read in edge environments Jun 6, 2025

teemingc added adapters - general Support for functionality general to all adapters and removed pkg:adapter-cloudflare labels Jun 6, 2025

Chew Tee Ming added 5 commits June 24, 2025 15:03

Merge branch 'main' into pr/vnphanquang/13859

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reword changesets

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clean up test

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workers and pages are essentially the same, so we only need one

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implement for vercel and netlify

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teemingc added pkg:adapter-vercel Pertaining to the Vercel adapter pkg:adapter-netlify pkg:adapter-cloudflare labels Jun 24, 2025

Chew Tee Ming added 2 commits June 24, 2025 17:44

lockfile

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format

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dominikg reviewed Jul 11, 2025

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dominikg reviewed Jul 11, 2025

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Comment thread packages/adapter-vercel/package.json Outdated

Chew Tee Ming and others added 8 commits July 14, 2025 09:50

Merge branch 'main' into pr/vnphanquang/13859

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clear output in plugin instead of npm script

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tweak

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avoid new SvelteKit export by handling promises in internal read impl…

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…ementation

oops

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Merge branch 'main' into pr/vnphanquang/13859

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annoying temporary workaround that will break the version.spec unit test

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fix

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dummdidumm reviewed Jul 15, 2025

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Chew Tee Ming added 5 commits July 16, 2025 10:38

ignore deno.lock

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split version string once

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Merge branch 'main' into pr/vnphanquang/13859

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format

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generate types

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teemingc approved these changes Jul 16, 2025

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dummdidumm merged commit cf88369 into sveltejs:main Jul 17, 2025
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github-actions Bot mentioned this pull request Jul 17, 2025

Version Packages #14002

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This was referenced Jul 29, 2025

docs: "What's new in Svelte" August newsletter sveltejs/svelte.dev#1433

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docs: mention read works in edge environments #14085

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Nic-Polumeyv mentioned this pull request Jul 21, 2026

fix: await init on every request to prevent race condition #16467

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