Issue 4795 - Use modern JavaScript syntax

lib/utils.js

Index: lib/utils.js
diff --git a/lib/utils.js b/lib/utils.js
index e965cad717e4cb7f2c19a8181a4edbebf322f14c..bb3fd5accda9f80ce6dd74cd52a08a0daa19c5a0 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -15,19 +15,21 @@
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-var Utils = exports.Utils = {
+"use strict";
+
+let Utils = exports.Utils = {
   systemPrincipal: null,
-  getString: function(id)
+  getString(id)
   {
     return ext.i18n.getMessage("global_" + id);
   },
-  runAsync: function(callback)
+  runAsync(callback)
   {
     if (document.readyState == "loading")
     {
       // Make sure to not run asynchronous actions before all
       // scripts loaded. This caused issues on Opera in the past.
-      let onDOMContentLoaded = function()
+      let onDOMContentLoaded = () =>
       {
         document.removeEventListener("DOMContentLoaded", onDOMContentLoaded);
         callback();
@@ -41,40 +43,38 @@ var Utils = exports.Utils = {
   },
   get appLocale()
   {
-    var locale = ext.i18n.getMessage("@@ui_locale").replace(/_/g, "-");
+    let locale = ext.i18n.getMessage("@@ui_locale").replace(/_/g, "-");
     Object.defineProperty(this, "appLocale", {value: locale, enumerable: true});
     return this.appLocale;
   },
-  generateChecksum: function(lines)
+  // We cannot calculate MD5 checksums yet :-(

[Sebastian Noack, 2017/01/18 11:24:27]

Moving the comment here seems unrelated.

[kzar, 2017/01/18 11:46:38]

Whoops, well spotted. Done.

+  generateChecksum(lines)
   {
-    // We cannot calculate MD5 checksums yet :-(
     return null;
   },
-  checkLocalePrefixMatch: function(prefixes)
+  checkLocalePrefixMatch(prefixes)
   {
     if (!prefixes)
       return null;
 
-    var list = prefixes.split(",");
-    for (var i = 0; i < list.length; i++)
-      if (new RegExp("^" + list[i] + "\\b").test(this.appLocale))
-        return list[i];
+    for (let prefix of prefixes.split(","))
+      if (new RegExp("^" + prefix + "\\b").test(this.appLocale))
+        return prefix;
 
     return null;
   },
 
-  chooseFilterSubscription: function(subscriptions)
+  chooseFilterSubscription(subscriptions)
   {
-    var selectedItem = null;
-    var selectedPrefix = null;
-    var matchCount = 0;
-    for (var i = 0; i < subscriptions.length; i++)
+    let selectedItem = null;
+    let selectedPrefix = null;
+    let matchCount = 0;
+    for (let subscription of subscriptions)
     {
-      var subscription = subscriptions[i];
       if (!selectedItem)
         selectedItem = subscription;
 
-      var prefix = require("utils").Utils.checkLocalePrefixMatch(subscription.getAttribute("prefixes"));
+      let prefix = require("utils").Utils.checkLocalePrefixMatch(subscription.getAttribute("prefixes"));

[Sebastian Noack, 2017/01/18 11:24:27]

Is require("utils") even necessary? Couldn't we just access Utils directly?

[kzar, 2017/01/18 11:46:37]

Yes I can't see why not, Done.

       if (prefix)
       {
         if (!selectedPrefix || selectedPrefix.length < prefix.length)
@@ -102,14 +102,14 @@ var Utils = exports.Utils = {
     return selectedItem;
   },
 
-  getDocLink: function(linkID)
+  getDocLink(linkID)
   {
-    var Prefs = require("prefs").Prefs;
-    var docLink = Prefs.documentation_link;
+    const {Prefs} = require("prefs");

[Sebastian Noack, 2017/01/18 11:24:28]

In this case, perhaps just inline it:

  let docLink = require('prefs').Prefs.documentation_link;

[kzar, 2017/01/18 11:46:38]

Done.

+    let docLink = Prefs.documentation_link;
     return docLink.replace(/%LINK%/g, linkID).replace(/%LANG%/g, Utils.appLocale);
   },
 
-  yield: function()
+  yield()
   {
   }
 };