As of adapter-cloudflare@5.0.0, SvelteKit no longer uses esbuild to bundle the build. This is because Cloudflare's Wrangler also bundles the worker code when you try to deploy the project. We don't want to duplicate the bundling process so we let Cloudflare handle it instead (less error prone).

You should probably adjust your project's GitHub workflows to upload/download the entire ./svelte-kit directory instead of just ./svelte-kit/cloudflare so that Cloudflare can correctly bundle the files that the worker relies on that are outside the .svelte-kit/cloudflare directory. We can't copy the server files to that directory because they will be made public by Cloudflare Pages.

1. https://github.com/trakt/trakt-lite/blob/05c0af44a38120a68626ea57d34c3859f3424705/.github/actions/upload-output/action.yml#L24
2. https://github.com/trakt/trakt-lite/blob/05c0af44a38120a68626ea57d34c3859f3424705/.github/workflows/cd.yml#L27

@eltigerchino I tried again including the entire build output (intially when I opened the issue I included only the output and cloudfare directories).

As you can see in this run: https://github.com/trakt/trakt-lite/actions/runs/12756619076/job/35555130981#step:5:72

Publishing these binaries result in cloudflare erroring on external dependencies, I've temporarily reverted the upgrade (again) trakt/trakt-lite#277.

@eltigerchino I tried again including the entire build output (intially when I opened the issue I included only the output and cloudfare directories).

As you can see in this run: trakt/trakt-lite/actions/runs/12756619076/job/35555130981#step:5:72

Publishing these binaries result in cloudflare erroring on external dependencies, I've temporarily reverted the upgrade (again) trakt/trakt-lite#277.

I forgot, you probably need to have your node_modules folder as well or else Wrangler won't be able to bundle the dependencies your code is referencing.

@eltigerchino this sort of defeats the purpose of a deployment pipeline.

We build our artifacts and deploy later (could be arbitrary time later...).

From where I come from a build artifact is deployable at any point in time...

So I've been thinking, I can understand you guys want to skip the build step (conceptually) but then I believe that the adapter should at a minimum:

• copy node_modules packages referenced by the output

Also can we please re-open this issue @eltigerchino I don't see this as resolved 😕

I have the same issue.

I understand that some build task is now moved for wrangler, but in that case could wrangler provide a tool to bundle the build into a single package/dist folder, etc. ? A self contained artifact is quite essential for many pipelines where a (tested) artifact can be deployed any time (to any compatible environment).

It's possible to compile the _worker.js file through the wrangler deploy --dry-run CLI command, but it might be better if we had a Wrangler API to bundle the worker for us.
cc: @dario-piotrowicz @petebacondarwin @jamesopstad

As a workaround for now, you could install wrangler and modify your build script like below and it should work:

# bundles the worker to a temp directory then copies it over to .svelte-kit/cloudflare
vite build && wrangler deploy ./.svelte-kit/cloudflare/_worker.js --dry-run --outdir ./.svelte-kit/cloudflare-tmp --name worker --compatibility-date 2025-02-03 && cp ./.svelte-kit/cloudflare-tmp/_worker.js ./.svelte-kit/cloudflare/_worker.js

#13072 is related as that removes the custom bundle step too

It's possible to compile the _worker.js file through the wrangler deploy --dry-run CLI command, but it might be better if we had a Wrangler API to bundle the worker for us. cc: @dario-piotrowicz @petebacondarwin @jamesopstad

As a workaround for now, you could install wrangler and modify your build script like below and it should work:

bundles the worker to a temp directory then copies it over to .svelte-kit/cloudflare

vite build && wrangler deploy ./.svelte-kit/cloudflare/_worker.js --dry-run --outdir ./.svelte-kit/cloudflare-tmp --name worker --compatibility-date 2025-02-03 && cp ./.svelte-kit/cloudflare-tmp/_worker.js ./.svelte-kit/cloudflare/_worker.js
#13072 is related as that removes the custom bundle step too

At the very least, while waiting for a proper fix, is it possible to update the adaptor docs to point new comers into the right direction?

I imagine it can be very frustrating to follow the docs just to run into this issue without knowing any workaround. 😂

Sorry this took a while. I think I've found a pretty satisfying fix that uses existing Cloudflare Wrangler behaviour. You can try out the fix before it's released by installing the adapter:

npm add https://pkg.pr.new/sveltejs/kit/@sveltejs/adapter-cloudflare@13610

There's an undocumented feature that allows us to write all server files to a _worker.js/ directory. This means we don't have to bundle it as a _worker.js file in addition to Wrangler's bundling (previous behaviour) and we get to keep all server files in the build output folder again.

However, copying the build output and uploading it directly through the Cloudflare Pages dashboard does not work because it doesn't detect the _worker.js/ directory and bundle it.

Had to revert the PR as the build output was still missing the server dependencies. To get a build artefact, we'd need to bundle the server dependencies in a way that doesn't cause all the issues we previously had. The safest way to do this would be to wait for Cloudflare to provide a Wrangler API to bundle everything as a single worker file. Or we could try to get the adapter to influence the Vite build and enable ssr.noExternal to bundle the deps (which may or may not cause us to have the same issues as before).

Really looking forward to this being fixed, we just migrated our app to CF workers so upgraded to the latest adapter. Had to sadly do my deployment part of the CI step now to avoid this issue 😔