FlexMock 0.4.0 Released

FlexMock is a flexible mocking library for use in Ruby's Test::Unit test framework. Version 0.4.0 enhances FlexMock with the ability to stub and mock methods in existing objects.

Changes

New Features in 0.4.0

What is FlexMock?

FlexMock is a flexible Ruby mocking library that works with Ruby's Test::Unit framework to create easy to use mocks.

Features

Example

Suppose you had a Dog object that wagged a tail when it was happy. Something like this:

class Dog
  def initialize(a_tail)
    @tail = a_tail
  end
  def happy
    @tail.wag
  end
end

To test the Dog class without a real Tail object (perhaps because real Tail objects activate servos in some robotic equipment), you can do something like this:

require 'test/unit' require 'flexmock'

class TestDog < Test::Unit::TestCase
  include FlexMock::TestCase

  def test_dog_wags_tail_when_happy
    tail = flexmock("tail")
    tail.should_receive(:wag).once
    dog = Dog.new(tail)
    dog.happy
  end
end

FlexMock will automatically verify that the mocked tail object received the message wag exactly one time. If it doesn't, the test will not pass.

See the FlexMock documentation at onestepback.org/software/flexmock for details on specifying arguments and return values on mocked methods, as well as a simple technique for mocking tail objects when the Dog class creates the tail objects directly.

Availability

FlexMock is distributed with Rails, or you can make sure you have the latest version with a quick RubyGems command:

gem install flexmock    (you may need root/admin privileges)

Otherwise, you can get it from the more traditional places:

Download

rubyforge.org/project/showfiles.php?group_id=170

You will find documentation at: onestepback.org/software/flexmock/

-- Jim Weirich