Comparators registration moved to separate file

Tests/UnitTests/GUI/Comparators.cpp

+#include "Comparators.h"
+#include "ComboProperty.h"
+#include "ExternalProperty.h"
+#include <QMetaType>
+
+bool Comparators::m_is_registered = false;
+
+void Comparators::registerComparators()
+{
+    QMetaType::registerComparators<ComboProperty>();
+    QMetaType::registerComparators<ExternalProperty>();
+    m_is_registered = true;
+}
+
+bool Comparators::registered()
+{
+    return m_is_registered;
+}

Tests/UnitTests/GUI/Comparators.h

+#ifndef COMPARATORS_H
+#define COMPARATORS_H
+
+//! Helper class to register custom variants comparators and to report
+//! unit tests if comparators should be tested.
+
+class Comparators
+{
+public:
+    static void registerComparators();
+    static bool registered();
+
+private:
+    static bool m_is_registered;
+};
+
+#endif  // COMPARATORS_H

Tests/UnitTests/GUI/TestComboProperty.h

 #include "google_test.h"
 #include "ComboProperty.h"
+#include "Comparators.h"
 #include "test_utils.h"
 
 class TestComboProperty :  public ::testing::Test
@@ -35,6 +36,9 @@ TEST_F(TestComboProperty, test_ComboEquality)
         EXPECT_TRUE(c1 == c2);
 }
 
+//! Check equality of ComboPeroperty's variants.
+//! If comparators are not registered, the behavior is undefined.
+
 TEST_F(TestComboProperty, test_VariantEquality)
 {
     QVariant v1(1.0);
@@ -45,16 +49,22 @@ TEST_F(TestComboProperty, test_VariantEquality)
 
     ComboProperty c1 = ComboProperty() << "a1" << "a2";
     ComboProperty c2 = ComboProperty() << "a1" << "a2";
-    EXPECT_TRUE(c1.variant() == c2.variant());
 
-    c2 << "a3";
-    EXPECT_TRUE(c1.variant() != c2.variant());
-    c2.setValue("a2");
-    EXPECT_TRUE(c1.variant() != c2.variant());
+    if (Comparators::registered()) {
+        EXPECT_TRUE(c1.variant() == c2.variant());
+
+        c2 << "a3";
+        c2.setValue("a2");
+
+        EXPECT_TRUE(c1.variant() != c2.variant());
+        EXPECT_FALSE(c1.variant() == c2.variant());
 
-    c1 << "a3";
-    c1.setValue("a2");
-    EXPECT_TRUE(c1.variant() == c2.variant());
+        c1 << "a3";
+        c1.setValue("a2");
+
+        EXPECT_TRUE(c1.variant() == c2.variant());
+        EXPECT_FALSE(c1.variant() != c2.variant());
+    }
 }
 
 TEST_F(TestComboProperty, test_setValue)

Tests/UnitTests/GUI/TestExternalProperty.h

 #include "google_test.h"
 #include "ExternalProperty.h"
+#include "Comparators.h"
 #include "test_utils.h"
 
 class TestExternalProperty :  public ::testing::Test
@@ -55,18 +56,24 @@ TEST_F(TestExternalProperty, test_equalityOperators)
 }
 
 //! Testing equality operators for QVariants based on ExternalProperty.
-//! Comparators should be enabled in main.cpp
+//! If comparators are not registered, the behavior is undefined
 
 TEST_F(TestExternalProperty, test_variantEquality)
 {
     ExternalProperty prop1;
     ExternalProperty prop2;
 
-    EXPECT_TRUE(prop1.variant() == prop2.variant());
-    prop1.setIdentifier("aaa");
-    EXPECT_TRUE(prop1.variant() != prop2.variant());
-    prop2.setIdentifier("aaa");
-    EXPECT_TRUE(prop1.variant() == prop2.variant());
+    if (Comparators::registered()) {
+        EXPECT_TRUE(prop1.variant() == prop2.variant());
+        prop1.setIdentifier("aaa");
+
+        EXPECT_TRUE(prop1.variant() != prop2.variant());
+        EXPECT_FALSE(prop1.variant() == prop2.variant());
+
+        prop2.setIdentifier("aaa");
+
+        EXPECT_TRUE(prop1.variant() == prop2.variant());
+    }
 }
 
 TEST_F(TestExternalProperty, test_toXML)

Tests/UnitTests/GUI/TestGUI.cpp

 #include "google_test.h"
 #include <QString>
 #include <QCoreApplication>
-#include "ComboProperty.h"
+#include "Comparators.h"
 
 #include "TestComboProperty.h"
 #include "TestComponentProxyModel.h"
@@ -46,8 +46,7 @@ int main(int argc, char** argv) {
     QCoreApplication app(argc, argv);
     Q_UNUSED(app);
 
-    QMetaType::registerComparators<ComboProperty>();
-    QMetaType::registerComparators<ExternalProperty>();
+    Comparators::registerComparators();
     qRegisterMetaType<QAbstractItemModel::LayoutChangeHint>("LayoutChangeHint");
 
     ::testing::InitGoogleTest(&argc, argv);