unittests: add setup code to call param_init()

unittests/CMakeLists.txt

@@ -105,7 +105,7 @@ endfunction()
 #    add_gtest(example_test)
 
 # param_test
-add_executable(param_test param_test.cpp uorb_stub.cpp
+add_executable(param_test setup.cpp param_test.cpp uorb_stub.cpp
 						${PX4_SRC}/modules/systemlib/bson/tinybson.c
 						${PX4_SRC}/modules/systemlib/param/param.c)
 target_link_libraries(param_test ${PX4_PLATFORM})

unittests/setup.cpp

@@ -0,0 +1,23 @@
+#include <systemlib/param/param.h>
+
+#include "gtest/gtest.h"
+
+
+class TestEnvironment: public ::testing::Environment {
+public:
+	/**
+	 * Testing setup: this is called before the actual tests are executed.
+	 */
+	virtual void SetUp()
+	{
+		param_init();
+	}
+};
+
+int main(int argc, char* argv[])
+{
+	::testing::InitGoogleTest(&argc, argv);
+	// gtest takes ownership of the TestEnvironment ptr - we don't delete it.
+	::testing::AddGlobalTestEnvironment(new TestEnvironment);
+	return RUN_ALL_TESTS();
+}