Add: unit test functionality using catch2

(cherry picked from commit 43a7e54067)

src/tests/test_main.cpp

@@ -0,0 +1,29 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file test_main.cpp Entry point for all the unit tests. */
+
+#include "../stdafx.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#define CATCH_CONFIG_MAIN
+#define DO_NOT_USE_WMAIN
+#include "../3rdparty/catch2/catch.hpp"
+
+void CDECL error(const char *s, ...)
+{
+	va_list va;
+	char buffer[1024];
+
+	va_start(va, s);
+	vsnprintf(buffer, 1024, s, va);
+	va_end(va);
+
+	CATCH_RUNTIME_ERROR(buffer);
+}