RSpec::Matchers.define :exit_with_code do |exp_code| actual = nil match do |block| begin block.call rescue SystemExit => e actual = e.status end actual and actual == exp_code end failure_message_for_should do |block| "expected block to call exit(#{exp_code}) but exit" + (actual.nil? ? " not called" : "(#{actual}) was called") end failure_message_for_should_not do |block| "expected block not to call exit(#{exp_code})" end description do "expect block to call exit(#{exp_code})" end end