Made sure FilterEngine instances are always initialized

test/JsEngine.cpp

Index: test/JsEngine.cpp
===================================================================
--- a/test/JsEngine.cpp
+++ b/test/JsEngine.cpp
@@ -17,16 +17,22 @@
 
 #include "BaseJsTest.h"
 
 namespace
 {
   class JsEngineTest : public BaseJsTest
   {
   };
+
+  bool callbackCalled = false;
+  void Callback()
+  {
+    callbackCalled = true;
+  }
 }
 
 TEST_F(JsEngineTest, Evaluate)
 {
   jsEngine->Evaluate("function hello() { return 'Hello'; }");
   AdblockPlus::JsValuePtr result = jsEngine->Evaluate("hello()");
   ASSERT_TRUE(result->IsString());
   ASSERT_EQ("Hello", result->AsString());
@@ -58,16 +64,41 @@ TEST_F(JsEngineTest, ValueCreation)
   ASSERT_TRUE(value->IsBool());
   ASSERT_TRUE(value->AsBool());
 
   value = jsEngine->NewObject();
   ASSERT_TRUE(value->IsObject());
   ASSERT_EQ(0u, value->GetOwnPropertyNames().size());
 }
 
+TEST_F(JsEngineTest, EventCallbacks)
+{
+  // Trigger event without a callback
+  callbackCalled = false;
+  jsEngine->Evaluate("_triggerEvent('foobar')");
+  ASSERT_FALSE(callbackCalled);
+
+  // Set callback
+  jsEngine->SetEventCallback("foobar", Callback);
+  callbackCalled = false;
+  jsEngine->Evaluate("_triggerEvent('foobar')");
+  ASSERT_TRUE(callbackCalled);
+
+  // Trigger a different event
+  callbackCalled = false;
+  jsEngine->Evaluate("_triggerEvent('barfoo')");
+  ASSERT_FALSE(callbackCalled);
+
+  // Remove callback
+  jsEngine->RemoveEventCallback("foobar");
+  callbackCalled = false;
+  jsEngine->Evaluate("_triggerEvent('foobar')");
+  ASSERT_FALSE(callbackCalled);
+}
+
 TEST(NewJsEngineTest, CallbackGetSet)
 {
   AdblockPlus::JsEnginePtr jsEngine(AdblockPlus::JsEngine::New());
 
   ASSERT_TRUE(jsEngine->GetLogSystem());
   ASSERT_ANY_THROW(jsEngine->SetLogSystem(AdblockPlus::LogSystemPtr()));
   AdblockPlus::LogSystemPtr logSystem(new AdblockPlus::DefaultLogSystem());
   jsEngine->SetLogSystem(logSystem);