Project don't work with chrome's new Manifest v3, can be easily fixed

In manifest v3 background workers are run as service workers. This means they don’t have access to window. https://developer.chrome.com/docs/extensions/mv3/intro/mv3-overview/#service-workers

The if-statement checking if window is present ruins it for the background script

// if not in a browser, assume we're in a test, return a dummy
if (typeof window === "undefined") exports.browser = {};
else exports.browser = require("webextension-polyfill");

If I just remove the if-else this library seems to be working fine for Manifest V3.

🙏 Please remove it, for testing jsdom can be used to fake window/document stuff…

[Lusito]

This polyfill adds the types for browser.action, but keep in mind, that firefox does not actually have browser.action implemented yet. So you should check if browser.action exists if you want to support browsers other than chrome. For example:

const action = browser.action || browser.browserAction;

[Lusito]

@AhsanAyaz Since then we have moved to @types/webextension-polyfill, so this package no longer provides any code.

If you have switched to @types/webextension-polyfill, the only place this might be caused is in the actual code repo: https://github.com/mozilla/webextension-polyfill.