The end of the first chapter of Professional WordPress Plugin Development by Wrox Press released February 2011 states:
To test a plugin during development make a
test.phpfile and place it in the WordPress installation root directory.
However I've run a search in Aptana Studio for
test.php in the WordPress
source code and cannot find it. Where is the code which supposedly loads
this file from WordPress's root directory and does it have to be named
test.php or can it be also named something else?