1576769 - Requests from WebExtensions aren't handled by service workers

Status: RESOLVED INCOMPLETE

(Core :: DOM: Service Workers, enhancement, P3)

Description

[David Konir]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0

Steps to reproduce:

• Visit a website that installs a service worker
• In an extension background page, initiate a fetch(), XmlHttpRequest, or browser.downloads.download() with a URL that should be handled by the service worker

Actual results:

Extension receives result directly from the website.

Expected results:

Service worker intercepts and handles the request.

Comment 1

[Kris Maglione [:kmag]]

I'm inclined to say that the current behavior is probably correct.

Comment 2

[David Konir]

(In reply to Kris Maglione [:kmag] from comment #1)

I'm inclined to say that the current behavior is probably correct.

It would seem so, yes. But then extensions can't access resources that are served by service workers while offline.

Comment 3

[Andrew Sutherland [:asuth] (he/him)]

(In reply to David Konir from comment #2)

(In reply to Kris Maglione [:kmag] from comment #1)

I'm inclined to say that the current behavior is probably correct.

Agreed. From a spec perspective, what's being discussed here amounts to foreign fetch which is no longer a thing under consideration.

It would seem so, yes. But then extensions can't access resources that are served by service workers while offline.

Have you tried initiating the fetch from a content script using fetch/XHR from the controlled page?

It could make sense to have specific APIs for something like this, but it's probably better to understand what the motivating use-case is first. Can you elaborate on the use-case?

In particular, while dispatching fake navigation fetches would probably work out okay, specific serviceworkers may expect clients to already exist for sub-resource fetches and/or be more than a naive proxy. In many cases, having the actual page setup in place is more likely to work out consistently.

Comment 4

[Jens Stutte [:jstutte]]

This reads like a potential spec change, not like a defect?

Comment 5

[Anne (:annevk)]

There's no real specification covering extensions. We can do whatever we want. It seems fine to me to close this particular request given that there's been no reply in 7 months though.