Issue 5198 - workaround for race condition in tests

test/FilterEngine.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 39 matching lines @@
     FilterEnginePtr filterEngine;
 
     void SetUp()
     {
       BaseJsTest::SetUp();
       jsEngine->SetFileSystem(AdblockPlus::FileSystemPtr(new FileSystem));
       jsEngine->SetWebRequest(AdblockPlus::WebRequestPtr(new LazyWebRequest));
       jsEngine->SetLogSystem(AdblockPlus::LogSystemPtr(new LogSystem));
       filterEngine = AdblockPlus::FilterEngine::Create(jsEngine);
     }
+    void TearDown() override

[hub, 2017/04/28 13:07:23]

I would add a comment here to point at the actual issue we are working around so
that we know this is to be properly fixed.

[sergei, 2017/04/28 13:14:33]

Agree, I thought that one will later trace it using blame from a version control
but it seems impractical because firstly one should really question that line,
having a comment in the code will help here.

+    {
+      std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    }
   };
 
   typedef FilterEngineTestGeneric<LazyFileSystem, AdblockPlus::DefaultLogSystem> FilterEngineTest;
   typedef FilterEngineTestGeneric<VeryLazyFileSystem, LazyLogSystem> FilterEngineTestNoData;
 
   class UpdaterTest : public ::testing::Test
   {
   protected:
     class MockWebRequest : public AdblockPlus::WebRequest
     {
@@ skipping 1007 matching lines @@
     filterEngine->SetAllowedConnectionType(&testConnection);
     auto subscription = EnsureExampleSubscriptionAndForceUpdate("subB");
     EXPECT_EQ("synchronize_ok", subscription.GetProperty("downloadStatus").AsString());
     EXPECT_EQ(1u, subscription.GetProperty("filters").AsList().size());
     auto capturedConnectionTypes = this->capturedConnectionTypes.GetStrings();
     ASSERT_EQ(1u, capturedConnectionTypes.size());
     EXPECT_TRUE(capturedConnectionTypes[0].first);
     EXPECT_EQ(testConnection, capturedConnectionTypes[0].second);
   }
 }