Issues with bundling date-fns

[danielroe]

Environment

node 20.9
nitro 2.7.2

Reproduction

https://stackblitz.com/edit/github-yysl4x?file=routes/index.ts,nitro.config.ts

You'll need to download locally to run wrangler

Describe the bug

Some libraries (specifically date-fns here) can be inlined incorrectly in cloudflare-pages output (for example) but I suspect any single-file output.

Downstream issue: nuxt/nuxt#23963

Additional context

No response

Logs

No response

[pi0]

Thanks for making issue with reproduction.

It seems a bug with rollup cjs plugin generated code.

Wrangler:

service core:user:worker: Uncaught TypeError: _interopRequireDefault2 is not a function
  at d9b7i8l49fs.js:7105:18
  at d9b7i8l49fs.js:7123:3
✘ [ERROR] MiniflareCoreError [ERR_RUNTIME_FAILURE]: The Workers runtime failed to start. There is likely additional logging output above.

Deno deploy:

error: The deployment failed: UNCAUGHT_EXCEPTION

TypeError: _interopRequireDefault is not a function
    at file:///src/server/index.ts:7086:18
    at file:///src/server/index.ts:7137:3

---

Re date-fns, it's dist format is CommonJS adding one _interopRequireDefault per function/entry from babel runtime which is it's dependencies also (example)!!! This is how many of them will be added by import { format } from 'date-fns' in dist/_worker.js:

I made (yet another) esm redist date-fns-es which is WIP (no subpaths for now but treeshakable) and might opensource it if cannot figure out a stable reproduction for the root cause of rollup/wrangler issue with CJS/babel helpers. (for reference, they planned esm support since 2020 date-fns/date-fns#1781)

"resolutions": {
    "date-fns": "npm:date-fns-es"
}

[MickL]

The same error happens on Vercel Edge Functions (it is working on normal Vercel Functions tho):

TypeError: t is not a function
at (index.mjs:1:110837)
at (index.mjs:1:110877)
at (__nitro:middleware.js:1:17)

And on Cloudflare Pages I get:

Error: Failed to publish your Function. Got error: Uncaught TypeError: r2 is not a function
at functionsWorker-0.5884842512200903.js:3588:12
at functionsWorker-0.5884842512200903.js:3590:2

Minimal reproduction repo (Nuxt 3): https://github.com/MickL/nuxt-datefns

I am not exactly sure if the issue is on Nitro side or date-fns? The ESM support issue at date-fns is open for more than 3 years with an open PR for more than one year.

[pi0]

@MickL Thanks for confirming. Yes this issue with bundling date-fns via rollup to an esm bundle applies for every bundled runtime.

If we cannot find an easy solution i think we shall start auto patching date-fns to esm version

[MickL]

date-fns has fixed this and it will be within the upcoming 3.0.0 release: date-fns/date-fns#1781 (comment)

[pi0]

Thanks for update @MickL. Checking 3.0.0-alpha.1 on unpkg, seems also babel dependency is droped 🤞🏼

[MickL]

I can confirm that date-fns 3.0.0-alpha.1 works on Vercel Edge functions (therefor I guess on Cloudflare Workers, too).

[MickL]

I think this can be close as completed! date-fns works fine since 3.0