webextension-polyfill

I mean, the browser apis are close (and Mozilla still has much better documentation) but there are a LOT of edges cases where behavior diverges. Frankly - I'm a little peeved that Optional permissions in Firefox are STILL broken - The prompt can only be triggered in response to a user action, and Firefox blows the fuck up if you put a promise anywhere in between the user click and the call to the api. Which is hugely ironic, since Mozilla is the one pushing to move all the webext APIs to be promise based (and provides a nice helpful library for Chrome/Edge/Safari support: https://github.com/mozilla/webextension-polyfill) which... doesn't work on their platform. Doubly ironic, since the result is that most FF extensions just ask for more permissions up front, which is exactly the opposite of what you'd want in the "secure/private" world

Yes: https://github.com/mozilla/webextension-polyfill

I'm going through converting a Chrome extension to Safari 14, and the process isn't nearly as seamless as shown, although it's nice to have the converter tool. Chrome extensions only support the 'chrome' namespace, while Firefox supports 'chrome' and 'browser', but Safari 14 only supports 'browser'. So our extension had been using the 'chrome' namespace which worked under Firefox, but now needed to be converted. 'chrome' uses callback functions, while 'browser' uses Promises. So you have to port your Chrome extension to use 'browser' and use the following polyfill: https://github.com/mozilla/webextension-polyfill Here's some incompatibilities between Chrome and Firefox to consider: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Web... Also had some html/css glitches to fix in Safari. Some other issues others have mentioned such