Issue 4231 - Fix unstable FilterEngineTest.testSetRemoveFilterChangeCallback

libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java

Index: libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
===================================================================
--- a/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
+++ b/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
@@ -28,10 +28,16 @@
     protected void setUp() throws Exception
     {
         super.setUp();
 
         jsEngine.setWebRequest(new LazyWebRequest());
         jsEngine.setDefaultLogSystem();
 
         filterEngine = new FilterEngine(jsEngine);
+
+        // JsEngine has built-in default subscriptions
+        while (filterEngine.getListedSubscriptions().size() > 0)

[sergei, 2016/07/07 12:48:42]

It seems there is a race condition because the number of subscriptions can be
zero if they are not loaded yet. They can be loaded during the following
Thread.sleep for example.
So actually, firstly one needs to check the number of subscriptions, if it's
zero then wait for loading (using FilterNotifier.addListener, action == "load")
and only then one can remove them. If it's bigger than zero it means the loading
finished and they can be removed as it's done now.

Here is an example of waiting for the finishing of the loading of subscriptions
https://hg.adblockplus.org/abpcrawler/file/tip/lib/crawler.js#l214

[anton, 2016/07/07 13:33:54]

ok, since it's not good enough solution for the case #2 i'd prefer to prevent
default subscriptions to be loaded at all and switch to solution #3.

+            filterEngine.getListedSubscriptions().get(0).removeFromList();
+
+        Thread.sleep(100);
     }
 }