Arbitrary code execution in background script

Add-ons Add-on Support
#1

Hello.

I’d like to execute code from content scripts in background script context. Is it ok to use something like https://www.npmjs.com/package/comlink for this or it is not allowed?

Thanks.

#2

Have you tried it yet?
The available API in the content scripts is quite limited, usually nothing fancy works, and this looks quite fancy :slight_smile:.

Also, it’s forbidden to execute remote code - that is executing a code that’s not part of the addon:

Practically, regarding content scripts, if you want to execute some job in the background script, you use something like this:

const dataToSend = {foo: 'bar'};
const result = await browser.runtime.sendMessage({type: 'content_script_job', data: dataToSend});
console.log('background computed result:', result);

So sending a data to the background script, which then processes them and sends result - by returning a Promise in the https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/runtime/onMessage handler.

#3

Thanks for your reply!

So, as long as all code is included within extension, it is allowed?

Regarding your example, I already have it done like this, but I thought it would be more convenient for development to do it with something like the library mentioned.