Sentry does not init in browser extension's service worker

[ddomonkos]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/browser

SDK Version

8.21.0

Framework Version

No response

Link to Sentry event

No response

Reproduction Example/SDK Setup

No response

Steps to Reproduce

1. Have a Manifest V3 browser (Chrome) extension
2. Run Sentry.init in the service worker (this used to be the "background script")
3. Observe an error

Expected Result

Sentry initializes without error.

Actual Result

An error is printed out:

[Sentry] You cannot run Sentry this way in a browser extension, check: https://docs.sentry.io/platforms/javascript/best-practices/browser-extensions/

Relevant PRs:

• feat(browser): Prevent initialization in browser extensions #10844
• fix(browser): Improve browser extension error message check #12146

The problem is with the condition WINDOW === WINDOW.top. In a service worker, WINDOW is resolved to globalThis and globalThis.top is undefined.

However, AFAIK it still applies that service worker's context is not shared, i.e. it should be fine to initialize Sentry there.

[Lms24]

Hey @ddomonkos thanks for writing in!

However, AFAIK it still applies that service worker's context is not shared

Right, this is what we need to confirm. The serviceWorker's globalThis cannot be the same "instance" as window in the page. If they're not the same, Sentry.init along with global integratinos can be safely called.

Do you know if there's a unique property on the globalThis object of the service worker we can use to identify it?

[ddomonkos]

Hi @Lms24,

while I don't consider myself to be an expert in the service workers domain, I can observe that globalThis is an instance of ServiceWorkerGlobalScope on which you can find a serviceWorker property. I suppose we could check for the existence of that.

[Lms24]

Hey @ddomonkos I relaxed this check a bit in general in #13156 so that global scopes that are not the window global scope are generally exempted. For now I think this should fix your issue as well without special casing service workers. We'll merge this soon and include it in the next release.