Use named capture groups

script.js

@@ -0,0 +1,51 @@
+// ==UserScript==
+// @author       Dave Gallant
+// @description  Strip redirect links on forums.redflagdeals.com
+// @downloadURL  https://raw.githubusercontent.com/davegallant/rfd-redirect-stripper/main/script.js
+// @grant        none
+// @match        *://forums.redflagdeals.com/*
+// @name         RedFlagDeals Redirect Stripper
+// @namespace    http://tampermonkey.net/
+// @updateURL    https://raw.githubusercontent.com/davegallant/rfd-redirect-stripper/main/script.js
+// @version      0.0.1
+// ==/UserScript==
+
+(function() {
+    'use strict';
+
+    var Links = document.querySelectorAll('a.postlink, a.autolinker_link');
+
+    const REDIRECT_REGEX = [
+      {
+        name: 'Amazon',
+        pattern: 'www.amazon.ca/gp/redirect.html\\?ie=UTF8&location=(?<baseUrl>.*?)(&|ref%3D|%3F)',
+      },
+      {
+        name: 'Best Buy',
+        pattern: 'bestbuyca.(.*).net(.*)\\?u=(?<baseUrl>.*)',
+      },
+    ];
+
+    var StripRedirect = function(URL) {
+       for (var i = 0; i < REDIRECT_REGEX.length; i++) {
+         var rule = REDIRECT_REGEX[i];
+         var result = new RegExp(rule.pattern).exec(URL);
+         if (result) {
+          var newURL = result.groups.baseUrl;
+          try {
+              return decodeURIComponent(newURL);
+          } catch (e) {
+              console.log(e);
+              return URL;
+          }
+         }
+       }
+       return URL;
+    };
+
+    Links.forEach(function(Link) {
+        var ReferralURL = Link.href;
+        Link.href = StripRedirect(ReferralURL);
+    });
+
+})();