Serviceworker and cannot use import statement outside a module

Question

I have an react-example of a service worker, with import statements. Like:

import { clientsClaim } from 'workbox-core';

If I use this code (react) in my service-worker, I get the message:

Uncaught SyntaxError: Cannot use import statement outside a module (at service-worker.js:1:1)

Where is the mistake?

user_385997 · Answer

The Workbox documentation has some more examples of this usage. Any bundler that supports ES modules should work; I tend to use esbuild nowadays.