I don't think the launcher has unit tests.

The if statement in process() that calls show_python_list only checks for "-0". It needs to check for the long names as well, e.g.:

    if (argc == 2) {
        /* First check for -0[p], --list, or --list-paths. */
        if (!wcsncmp(p, L"-0", 2) || !wcscmp(p, L"--list") ||
            !wcscmp(p, L"--list-paths")) {
            valid = show_python_list(argv);
        }
    }

show_python_list shouldn't need to be modified. It already looks for -0p and --list-paths to include paths in the output format.