QtTest: [skip ci] enable Qt testing framework

tests/src/InventorBuilder.cpp

@@ -0,0 +1,62 @@
+#include <QTest>
+#include <sstream>
+#include <Base/Builder3D.h>
+
+class testInventorBuilder : public QObject
+{
+    Q_OBJECT
+
+public:
+    testInventorBuilder()
+        : builder(output)
+    {
+    }
+    ~testInventorBuilder()
+    {
+    }
+
+private Q_SLOTS:
+    void initTestCase()
+    {
+
+    }
+    void initTestCase_data()
+    {
+
+    }
+    void cleanupTestCase()
+    {
+
+    }
+
+    void init()
+    {
+    }
+
+    void cleanup()
+    {
+        // clear the buffer
+        output.str(std::string());
+    }
+
+    void test_Output()
+    {
+        QCOMPARE(output.str().c_str(), "#Inventor V2.1 ascii \n\n");
+    }
+
+    void test_MaterialBinding()
+    {
+        Base::MaterialBindingItem item{Base::MaterialBinding{}};
+        builder.addNode(item);
+
+        QCOMPARE(output.str().c_str(), "MaterialBinding { value OVERALL } \n");
+    }
+
+private:
+    std::stringstream output;
+    Base::InventorBuilder builder;
+};
+
+QTEST_GUILESS_MAIN(testInventorBuilder)
+
+#include "InventorBuilder.moc"