bug-fix: 'tests' app would fail, depending on what directory it was

launched from

Author: DavidLudwig

P0267_RefImpl/Tests/main.cpp

@@ -1,4 +1,35 @@
-#define CATCH_CONFIG_MAIN
+
+#include <exception>
+#include <filesystem>
+#include <iostream>
+#include <system_error>
+
+#define CATCH_CONFIG_RUNNER
 #include "catch.hpp"
 
-// this is a stub to generate main() jazz.
+// io2d uses its own main(), rather than Catch's, so as to set the running
+// process' current working directory to that where input data files are
+// located.
+//
+// Catch2 describes how to do a custom main(), at:
+//   https://github.com/catchorg/Catch2/blob/master/docs/own-main.md
+
+int main(int argc, char* argv[])
+{
+	// For now, set the app's CWD (Current Working Directory) to where the
+	// app's executable is, presuming this info is available.
+	if (argc >= 1 && argv[0] != nullptr) {
+		try {
+			using namespace std::filesystem;
+			current_path(path(argv[0]).parent_path());
+		} catch (const std::exception & ex) {
+			std::cerr <<
+				"ERROR: Unable to set CWD via current_path(). what()=\"" <<
+				ex.what() <<
+				"\"\n";
+			return 1;	// Return a non-zero integer to indicate failure
+		}
+	}
+
+	return Catch::Session().run(argc, argv);
+}