Issue 7016 - Convert serialization functions into generators

lib/filterStorage.js

Index: lib/filterStorage.js
===================================================================
--- a/lib/filterStorage.js
+++ b/lib/filterStorage.js
@@ -481,46 +481,33 @@
         subscriptions.push(subscription);
       }
     }
 
     yield "# Adblock Plus preferences";
     yield "version=" + this.formatVersion;
 
     let saved = new Set();
-    let buf = [];
 
     // Save subscriptions
     for (let subscription of subscriptions)
     {
-      yield "";
-
-      subscription.serialize(buf);
-      if (subscription.filters.length)
-      {
-        buf.push("", "[Subscription filters]");
-        subscription.serializeFilters(buf);
-      }
-      for (let line of buf)
-        yield line;
-      buf.splice(0);
+      yield* subscription.serialize();
+      yield* subscription.serializeFilters();
     }
 
     // Save filter data
     for (let subscription of subscriptions)
     {
       for (let filter of subscription.filters)
       {
         if (!saved.has(filter.text))
         {
-          filter.serialize(buf);
+          yield* filter.serialize();
           saved.add(filter.text);
-          for (let line of buf)
-            yield line;
-          buf.splice(0);
         }
       }
     }
   }
 
   /**
    * Saves all subscriptions back to disk.
    * @returns {Promise} A promise resolved or rejected when saving is complete.