jQuery doesn't work on some websites only in firefox

Add-ons Development
#1

Hi,
This is my firefox addon: Sauron - Dark mode for all websites
And here is all the code available: https://github.com/rishabhmw/sauron

It works as expected in chrome but in firefox the jquery in content scripts doesn’t work for some websites such as facebook, quora, and nytimes. I either get jQuery.Deferred exception: $ is not defined mainReady@moz-extension://39071a01-0540-46e3-b16e-96bd576ca827/content.js:81:5 @moz-extension://39071a01-0540-46e3-b16e-96bd576ca827/content.js:139:13 l@moz-extension://39071a01-0540-46e3-b16e-96bd576ca827/jquery-3.3.1.min.js:2:29373 Deferred/then/a/</c<@moz-extension://39071a01-0540-46e3-b16e-96bd576ca827/jquery-3.3.1.min.js:2:29677 undefined or no error at all (very rarely) in the console.
If I try to manipulate DOM with just javascript it works but not with jQuery. Also If the page is already loaded when the extension is disabled and then if the extension is enabled after the page has loaded the DOM changes magically.
Please help,
Rishabh

#2

The problem seemed to stem from conflicting instances jQuery or conflicting Jquery scripts being loaded. Since all scripts in the extension itself work in harmony the problem must be with firefox. It seems that firefox doesn’t define different scopes for addon scripts and webpage scripts. Anyway little noConflict() magic was all that was needed.

#3

It does. However that doesn’t necessarily fix all the issues that jQuery could have with conflicts, since you are still trying to access the same DOM tree.

#4

It does. However that doesn’t necessarily fix all the issues that jQuery could have with conflicts, since you are still trying to access the same DOM tree.

I see, but the error was $: is not defined which means that $ was redefined (?) thus another script was running in the same scope as the content script? Even though we are interacting with the same DOM tree shouldn’t references not conflict on firefox if scopes are well defined and different just as they don’t on chrome. Let me know what you think about this matter.