Cloudflare adapter: Could not resolve "path" and "fs"

[apvarun]

Describe the bug

For deploying a markdown blog using sveltekit to cloudflare, it is required to read the file system to get the list of files. This fails after adding the cloudflare adapter

> Build failed with 11 errors:
.svelte-kit/output/server/chunks/_slug_.json-8564ef2a.js:1:17: error: Could not resolve "path" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/_slug_.json-8564ef2a.js:3:7: error: Could not resolve "fs" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/blog-5b3957a8.js:1:15: error: Could not resolve "fs" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/index.json-5265f1f0.js:1:17: error: Could not resolve "path" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/index.json-5265f1f0.js:3:7: error: Could not resolve "fs" (use "platform: 'node'" when building for node)

Reproduction

Clone Repo: https://github.com/rodneylab/sveltekit-blog-mdx
Run: npm i --save-dev @sveltejs/adapter-cloudflare@next
Change the adapter in svelte.config.js to cloudflare-adapter
Run npm run build

Logs

Error: Build failed with 11 errors:
.svelte-kit/output/server/chunks/_slug_.json-8564ef2a.js:1:17: error: Could not resolve "path" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/_slug_.json-8564ef2a.js:3:7: error: Could not resolve "fs" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/blog-5b3957a8.js:1:15: error: Could not resolve "fs" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/index.json-5265f1f0.js:1:17: error: Could not resolve "path" (use "platform: 'node'" when building for node)
.svelte-kit/output/server/chunks/index.json-5265f1f0.js:3:7: error: Could not resolve "fs" (use "platform: 'node'" when building for node)
...
    at failureErrorWithLog (/private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:1493:15)
    at /private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:1151:28
    at runOnEndCallbacks (/private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:1069:65)
    at buildResponseToResult (/private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:1149:7)
    at /private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:1258:14
    at /private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:629:9
    at handleIncomingPacket (/private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:726:9)
    at Socket.readFromStdout (/private/tmp/sveltekit-blog-mdx/node_modules/esbuild/lib/main.js:596:7)
    at Socket.emit (events.js:400:28)
    at addChunk (internal/streams/readable.js:290:12)
error Command failed with exit code 1.

System Info

System:
    OS: macOS 12.0.1
    CPU: (8) x64 Intel(R) Core(TM) i5-8257U CPU @ 1.40GHz
    Memory: 46.63 MB / 8.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 14.17.4 - ~/.nvm/versions/node/v14.17.4/bin/node
    Yarn: 1.22.5 - /usr/local/bin/yarn
    npm: 7.23.0 - ~/.nvm/versions/node/v14.17.4/bin/npm
  Browsers:
    Brave Browser: 95.1.31.88
    Chrome: 96.0.4664.55
    Firefox: 93.0
    Safari: 15.1
  npmPackages:
    @sveltejs/adapter-cloudflare: ^1.0.0-next.2 => 1.0.0-next.2
    @sveltejs/adapter-static: ^1.0.0-next.21 => 1.0.0-next.21
    @sveltejs/kit: ^1.0.0-next.182 => 1.0.0-next.196
    svelte: ^3.43.2 => 3.44.2

Severity

blocking all usage of SvelteKit

Additional Information

Prevent the deployment of the project. The build in cloudflare deployment environment also fails for the same reason.

[flayks]

Same problem here! Haven't got much luck on the Discord so far.

It would be lovely to have API endpoints working with CF pages since (I believe) the Cloudflare blog post says that it should now work with a Node environment.

[apvarun]

@flayks I'm able to get it to work after removing all node based dependencies. I was using path and fs packages for generating JSON in API, but then I had to move it to a script in prebuild and then consume it in my app. Not possible to have it dynamic via API routes.

[si3nloong]

Ah, I found the bug. Since the code is using path and fs which is belong to Nodejs API, but the platform was assigned as browser instead node, so esbuild throw errors when it compiling the codes.

kit/packages/adapter-cloudflare/index.js

Line 42 in f95801e

platform: 'browser',

I can solve this easily, but I think I need to understand why it is set to browser instead of node in the first place.

[raul-reclique]

Changing to platform 'node' fixes the building error but still does not deploy to cloudflare. Here is the example, it builds
but it fails "Deploying your site to Cloudflare's global network..."

20:50:15.106 | Run npm run preview to preview your production build locally.
-- | --
20:50:15.114 |  
20:50:15.114 | > Using @sveltejs/adapter-cloudflare
20:50:15.568 | ✔ done
20:50:15.585 | Finished
20:50:15.585 | Note: No functions dir at /functions found. Skipping.
20:50:15.585 | Found _worker.js in output directory. Uploading.
20:50:15.596 | Validating asset output directory
20:50:16.011 | Deploying your site to Cloudflare's global network...
20:50:24.954 | Failed: an internal error occurred

[babichjacob]

Cloudflare Workers do not run Node. While it looks weird that the platform being built for is browser, that's practically what it is since Cloudflare Workers run "just" V8, which means that the built-in Node libraries are not there. Changing the platform to node won't make Node libraries available on Workers, so you must change your code not to use Node libraries or packages that depend on them.

[Rich-Harris]

There's a few things that need to happen here to prevent this sort of thing:

• Make dev environment match production environment more closely #3535 — we need to more closely match the deployed environment during development, so these errors aren't surprising
• Mark endpoints as prerenderable #4093 — we need to know which endpoints are prerendered, so they can be excluded from functions (if stuff is prerendered during svelte-kit build, it's fine to use Node-isms like fs)
• Include non-imported assets in deployments #4671 — we need a way to load assets like markdown files

Since we have issues tracking all those things, I'll close this issue