The tests are not really intended to be run interactively, but if you look in the standard ruby ββlibrary and look at the file test/unit.rb, you will see that it installs a handler at_exitwhen you require 'test/unit':
at_exit do
unless $! || Test::Unit.run?
Kernel.exit Test::Unit::AutoRunner.run
end
end
Therefore, looking at this all you need to do in your session irbis called:
Test::Unit::AutoRunner.run
This will run all the tests you upload that subclass out Test::Unit::TestCase.
, irb, :
system 'ruby testfile.rb'