First extracting just the one line that generates the command
No need to pass $0 since it's global
Nor is there a need to pass $cmd. It's actually a kind of constant, but let's deal with that later
Generating $inc inside the method instead of passing it
Extracting arguments inside the new method so we don't need to pass an extra one
Tidyier way to concatenate the parts of the command
Replace obsolete _run_rhino() with more generic _run_os_command()
Wanting to move stuff to an object-oriented class. Starting with an empty one.
Moving find_test_lib() to the new runner class
Moving _generate_command() to the new runner class
Moving _run_os_command() to the new runner class
Moving _run_psgi() to the new runner class
Sorting out the command generation piece into a subclass
Adding subclass to generate command for Webspecter