Unittest in a windows app

[Dan Nestor via Digitalmars-d-learn]

Hello everybody, this is my first post on this forum.

I have a question about unit testing a Windows application. I
have slightly modified Visual D's default Windows application
stub to the following:

<code>
module winmain;

import core.runtime;
import core.sys.windows.windows;

unittest {
        assert(false);
}

extern (Windows)
int WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR
lpCmdLine, int nCmdShow)
{
        int result;

        void exceptionHandler(Throwable e)
        {
                throw e;
        }

        try
        {
                Runtime.initialize();
                result = myWinMain(hInstance, hPrevInstance, lpCmdLine,
nCmdShow);
                Runtime.terminate();
        }
        catch (Throwable o)             // catch any uncaught exceptions
        {
                MessageBoxA(null, cast(char *)o.toString(), "Error", MB_OK |
MB_ICONEXCLAMATION);
                result = 0;             // failed
        }

        return result;
}

int myWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR
lpCmdLine, int nCmdShow)
{
        /* ... insert user code here ... */
        throw new Exception("not implemented");
        return 0;
}
</code>

I compiled it with the `-unittest` option. Strangely, when
running the app, no error is displayed, and the application
proceeds as usual. I would expect the program to display the unit
test failure and stop (the behaviour I have observed for console
applications). What am I missing?

Thanks for helping!

Dan