GM_ APIs no longer supported in GM4

With the recent update to Firefox (FF57, aka Quantum) Greasemonkey devs have decided to change their API from synchronous functions GM_* to async methods of the GM object. This means that starting with GM4 (the first version compatible with FF57+) all scripts that used any of those functions will no longer work.

As an example, your awesome script for GitHub custom hotkeys in FF57+GM4 dies with “Script error: ReferenceError: GM_getValue is not defined” in the console.

A suggested workaround is to include an official polyfill for the old API. Also, I think most of them can be safely replaced with native fetch and localStorage.

[jerone]

I agree with you @Mottie. It started with GM4 not detecting my 50+ installed UserScripts. GM does not support drag-and-drop installation (after finding GM’s installation folder), and TamperMonkey does, so I switched to TM (also because it is available on all other browsers too). My personal feeling is that GM is forcing a new standard to us way too fast without being backwards-compatible (while TM is forwards-compatible (GM3 + GM4 style)). ~I only need to update documentation that GM4 is not supported for my UserScripts.~

[monk-time]

I’m sorry that the GM devs treated your suggestions that way, looks like it’s not a happy situation re: GM4 for everybody involved.

In any case, I’ve made GitHub Custom Hotkeys GM4-compatible by switching to native APIs in my fork, but I haven’t added any code for user data migration, so I am not sure whether it would make sense to send a PR or not.

And thank you once again for your scripts! They are immensely helpful.