Here’s an example extension that uses loadFrameScript and a listener. This kind of code worked in Firefox 55 and earlier (I’m using it in an actual addon with multi-year history), but fails in Firefox 56.
Or to be more specific, it does what’s expected when the tab is showing some chrome URL (like the Addons page) but does nothing in tabs that show web pages.
Expected behavior:
- Press Ctrl-Alt-D.
- See {num: 42} in the Browser Console.
The xpi is here: https://ufile.io/vagyh
What am I doing wrong?