class Enterprise def initialize(dilithium) @dilithium = dilithium end def go(warp_factor) warp_factor.times { @dilithium.nuke(:anti_matter) } end end require 'test/unit' require 'mocha' class EnterpriseTest < Test::Unit::TestCase def test_should_boldly_go dilithium = mock() dilithium.expects(:nuke).with(:anti_matter).at_least_once # auto-verified at end of test enterprise = Enterprise.new(dilithium) enterprise.go(2) end end