Mockr - easy Mock Objects for Ruby

Mockr is a pure Ruby library to support the Mock Objects approach to unit testing. Several other Mock Object libraries exist for Ruby. Mockr has two main distinguishing features:

1. Support for the distinction between mocking and stubbing
2. A constraint-based mechanism for matching call parameters

History and status

Mockr was begun in March 2005 and is based loosely on Java's JMock library. In fact, Mockr was originally called RMock, but it turned out the name was already used for a Java library.

It was presented at EuRuKo (European Ruby Conference) in October 2005 and is currently being polished for a public release.

Example

require 'test/unit'
require 'mockr'


## Collaborates with a LaserGrid and a PoliceStationUplink
class BurglarAlarm
  def initialize(laser_grid, police_link)
    @laser_grid = laser_grid
    @police_link = police_link
  end

  def check
    begin
      @police_link.incident("Grid breached") unless @laser_grid.intact?
    rescue
      @police_link.warning("Grid down")
    end
  end
end


class BurglarAlarmTest < Test::Unit::TestCase
  include Mockr::TestCaseHelpers

  def setup
    @laser_grid, @police_link = new_mock, new_mock
    @alarm = BurglarAlarm.new(@laser_grid.proxy, @police_link.proxy)
  end

  def test_police_station_not_contacted_if_grid_okay
    @laser_grid.expects.intact?.as { true }
    @alarm.check
  end

  def test_police_station_is_contacted_if_grid_not_okay
    @laser_grid.expects.intact?.as { false }
    @police_link.expects.incident("Grid breached")
    @alarm.check
  end

  def test_police_station_warned_if_grid_down
    @laser_grid.expects.intact?.as { raise IOError.new("comms down") }
    @police_link.expects.warning(/down/)   # A loose parameter constraint
    @alarm.check
  end

end

Getting it

Official releases are available in Gem form via Rubyforge, and can be installed with a simple gem install mockr.

To get the latest version, use git to access the master repository or download a snapshot tarball. See: http://git.sanityinc.com/?p=mockr.git;a=summary