When using `import` inside classic worker, syntax error happens during dev but build success

Describe the bug

When import is used in classic worker, the following error happens during dev.

Uncaught SyntaxError: Cannot use import statement outside a module

But build works with it and the bundle seems to be correctly bundled.

According to the docs, import can be used inside classic worker if worker is imported with query suffixes. There is no mention about constructor type worker import. But if it is the recommended way, I think it would be good to support it too. Also it is useful for #8466.

https://github.com/vitejs/vite/issues/8466#issuecomment-1146655205 might be related.

Reproduction

https://stackblitz.com/edit/vitejs-vite-mhmcjy?file=main.js

System Info

stackblitz

Vite: 2.9.9, 3.0.0-alpha.9

Used Package Manager

npm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn’t already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it’s a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[egriff38]

Following this issue. This is the biggest inhibitor to running workers with imports in dev mode with Firefox. I can’t be the only one who develops against Firefox, right?

[poyoho]

so the issue asks for

1. dynamic import support in classic worker (build mode)
2. static import support in classic worker (dev mode) 😵