add testing infrastructure

test/TestApp.cpp

@@ -0,0 +1,36 @@
+
+#include <gmock/gmock.h>
+#include <memory>
+
+#define private public
+#include <App.hpp>
+#undef private
+
+class TestApp : public testing::Test {
+
+    protected:
+
+    void createUut() {
+        uut_ = std::make_unique<App>();
+    }
+
+    std::unique_ptr<App> uut_;
+
+};
+
+TEST_F(TestApp, TestApp_run_nominal) {
+
+    createUut();
+    uut_->run();
+
+    // no expect here
+
+} 
+
+TEST_F(TestApp, TestApp_foo_nominal) {
+
+    createUut();
+
+    EXPECT_EQ(uut_->foo(), 12);
+
+}