Issue 6859 - Create special subscription group for snippet filters

lib/subscriptionClasses.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 /**
  * @fileOverview Definition of Subscription class and its subclasses.
  */
 
 const {ActiveFilter, BlockingFilter,
-       WhitelistFilter, ElemHideBase} = require("./filterClasses");
+       WhitelistFilter, ElemHideBase,
+       SnippetFilter} = require("./filterClasses");
 const {FilterNotifier} = require("./filterNotifier");
 const {extend} = require("./coreUtils");
 
 /**
  * Abstract base class for filter subscriptions
  *
  * @param {string} url    download location of the subscription
  * @param {string} [title]  title of the filter subscription
  * @constructor
  */
@@ skipping 260 matching lines @@
       );
     }
     if (this._lastDownload)
       buffer.push("lastDownload=" + this._lastDownload);
   }
 });
 
 SpecialSubscription.defaultsMap = new Map([
   ["whitelist", WhitelistFilter],
   ["blocking", BlockingFilter],
-  ["elemhide", ElemHideBase]
+  ["elemhide", ElemHideBase],
+  ["snippet", SnippetFilter]
 ]);
 
 /**
  * Creates a new user-defined filter group.
  * @param {string} [title]  title of the new filter group
  * @return {SpecialSubscription}
  */
 SpecialSubscription.create = function(title)
 {
   let url;
@@ skipping 259 matching lines @@
     if (this.errors)
       buffer.push("errors=" + this.errors);
     if (this.version)
       buffer.push("version=" + this.version);
     if (this.requiredVersion)
       buffer.push("requiredVersion=" + this.requiredVersion);
     if (this.downloadCount)
       buffer.push("downloadCount=" + this.downloadCount);
   }
 });