Issue 6829 - Free filters when subscriptions are empty

test/filterStorage.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
@@ skipping 477 matching lines @@
 
   compareFilterSubscriptions(test, "filter1 subscriptions after updating http://test3/ filters", filter1, [subscription3]);
   compareFilterSubscriptions(test, "filter2 subscriptions after updating http://test3/ filters", filter2, [subscription2, subscription3]);
   compareFilterSubscriptions(test, "filter3 subscriptions after updating http://test3/ filters", filter3, [subscription2]);
 
   FilterStorage.removeSubscription(subscription3);
 
   compareFilterSubscriptions(test, "filter1 subscriptions after removing http://test3/", filter1, []);
   compareFilterSubscriptions(test, "filter2 subscriptions after removing http://test3/", filter2, [subscription2]);
   compareFilterSubscriptions(test, "filter3 subscriptions after removing http://test3/", filter3, [subscription2]);
+  test.equal(Filter.knownFilters[filter1.text], undefined);

[Jon Sonesen, 2018/08/30 17:11:42]

This test is currently a noop (removing changes does not effect outcome) Not
sure exactly how to test this change here but I realize it should be done.

 
   test.done();
 };