Typescript error TP1001 when creating a Web Worker in Next.js 15.1.3

[farzadsoltani]

Link to the code that reproduces this issue

https://github.com/farzadso/workers-issue

To Reproduce

Run npm run dev and you can see the issue.

Current vs. Expected behavior

There should be no errors in the console.

This is the error I see:

 ⚠ ./app/page.tsx:9:22
error TP1001 new Worker("/workers/timer.js") is not statically analyse-able
   7 |
   8 |   useEffect(() => {
>  9 |     ticker.current = new Worker("/workers/timer.js");
     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  10 |   }, []);
  11 |   return <div>Test</div>;
  12 | }

If I remove --turbopack from the dev script it works fine.

I noticed this happening after my upgrade to Next.js 15 and using Turbopack for dev builds.

The Web Worker is being created dynamically, and it works fine, so I don't see any issues with the functionality.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.2.0: Fri Dec  6 19:02:12 PST 2024; root:xnu-11215.61.5~2/RELEASE_ARM64_T6031
  Available memory (MB): 36864
  Available CPU cores: 14
Binaries:
  Node: 20.15.1
  npm: 10.7.0
  Yarn: 1.22.22
  pnpm: N/A
Relevant Packages:
  next: 15.2.0-canary.0 // Latest available version is detected (15.2.0-canary.0).
  eslint-config-next: N/A
  react: 19.0.0
  react-dom: 19.0.0
  typescript: 5.7.2
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Not sure

Which stage(s) are affected? (Select all that apply)

next dev (local)

Additional context

No response

[sam-skydio]

also experiencing this issue after attempting to turn on Turbopack, would appreciate some guidance here.

[farzadsoltani]

@sam-skydio I'm just ignoring it for now as it seems to be working on the client side and not causing any issues when building for prod as the prod build doesn't use Turbopack.

[bbsweb]

use window.Worker instead of Worker

ticker.current = new window.Worker("/workers/timer.js");

[farzadsoltani]

use window.Worker instead of Worker

ticker.current = new window.Worker("/workers/timer.js");

Thank you. That actually worked and suppressed it.

[mischnic]

You could also use one of these

new Worker(/* webpackIgnore: true */ "/workers/timer.js");
new Worker(/* turbopackIgnore: true */ "/workers/timer.js");

[farzadsoltani]

You could also use one of these

new Worker(/* webpackIgnore: true / "/workers/timer.js");
new Worker(/ turbopackIgnore: true */ "/workers/timer.js");

Thanks. Is this documented anywhere?