Proof-of-Concept Firefox Add-On to Redirect Before Page Loads

manifest.json

{
    "description": "Redirect AMP addresses to their non-AMP sources",
    "manifest_version": 2,
    "name": "AMP Redirect",
    "version": "0.1",
    "author": "Ultrabenosaurus",

    "_comments_": {
        "signed_xpi": "https://drive.google.com/file/d/1Pg19uXregtxfENnKO3tcvR2SiTu01IYf/view?usp=sharing",
        "source:": "https://gist.github.com/Ultrabenosaurus/b94d373f3a32d2b5d6ae5256e04784a7",
        "based_on": "https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/onBeforeRequest",
        "userscript": "https://greasyfork.org/en/scripts/400161-amp-redirect"
    },

    "permissions": [
        "webRequest",
        "webRequestBlocking",
        "<all_urls>"
    ],

    "background": {
        "scripts": ["redirect.js"]
    }
}

redirect.js

/**
*
* name         AMP Redirect
* namespace    ultrabenosaurus.AMP
* version      0.1
* description  Redirect AMP addresses to their non-AMP sources
* author       Ultrabenosaurus
* signed XPI   https://drive.google.com/file/d/1Pg19uXregtxfENnKO3tcvR2SiTu01IYf/view?usp=sharing
* source       https://gist.github.com/Ultrabenosaurus/b94d373f3a32d2b5d6ae5256e04784a7
* userscript   https://greasyfork.org/en/scripts/400161-amp-redirect
*
* Based on MDN web docs: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/onBeforeRequest
*
* from: https://www-techradar-com.cdn.ampproject.org/v/s/www.techradar.com/amp/news/eliminating-vpns-for-more-secure-productive-remote-work?amp_js_v=a3&amp_gsa=1&usqp=mq331AQFKAGwASA%3D#referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s
* to: https://www.techradar.com/news/eliminating-vpns-for-more-secure-productive-remote-work
*
*/

function UBredirect(requestDetails){
    // console.log(requestDetails);
    var a = requestDetails.url.split("/");
    // console.log(a);
    var al = a.length;
    var d = a[2].split(".")[0].replace(/-/g,".");
    // console.log(d);
    if(d == a[5]){
        var p = a[al-1].split("?")[0];
        for (var i = al-2; i > 6; i--) {
            if(a[i] !== "amp") { p = a[i]+"/"+p; }
            // console.log(a[i]);
        }
        // console.log(p);
        var s = a[0]+"//"+d+"/"+p;
        // console.log(s);
        return {
            redirectUrl: s
        };
    }
}

browser.webRequest.onBeforeRequest.addListener(
    UBredirect,
    {urls: ["<all_urls>"]},
    ["blocking"]
);

why was it not redirecting me for the example URL I have included in the comment block in the JS file?

https://www-techradar-com.cdn.ampproject.org/v/s/www.techradar.com/amp/news/eliminating-...?

These are supported:

        'https://www.bing.com/amp/*',
        'https://www.google.com/amp/*'

        'https://cdn.ampproject.org/c/*',
        'https://*.cdn.ampproject.org/c/*',
        'https://bing-amp.com/c/*',
        'https://*.bing-amp.com/c/*'

        '*://t.co/*?amp=1'

You should probably report few samples to the author - maybe he will add them.

Also, neither of the source links in your comment work for me:

Hmmm, seems you have network issues. Works for me on two different browsers and two devices.