This post originated from an RSS feed registered with Ruby Buzz by Jay Fields. Original Post: Ruby: Recording Method Calls and Playback With Inject Feed Title: Jay Fields Thoughts Feed URL: http://feeds.feedburner.com/jayfields/mjKQ Feed Description: Blog about Ruby, Agile, Testing and other topics related to software development. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Jay Fields Latest Posts From Jay Fields Thoughts

class SystemProcess
  def start
    puts "started"
    new StartedProcess
  end
end

Expectations do
  expect SystemProcess.new.to.receive(:start) do |process|
    process.start
  end
end

class Recorder
  attr_reader :subject
  def initialize(subject)
    @subject = subject
  end
  
  def replay
    method_stack.inject(subject) { |result, element| result.send element.first, *element.last }
  end
    
  def method_stack
    @method_stack ||= []
  end
  
  def method_missing(sym, *args)
    method_stack << [sym, args]
    self
  end
end

class SystemProcess
  def start(in_seconds)
    puts "starting in #{in_seconds}"
    sleep in_seconds
    StartedProcess.new
  end
end

class StartedProcess
  def pause(in_seconds)
    puts "pausing in #{in_seconds}"
    sleep in_seconds
    PausedProcess.new
  end
end

class PausedProcess
  def stop(in_seconds)
    puts "stopping in #{in_seconds}"
    sleep in_seconds
    self
  end
end

Recorder.new(SystemProcess.new).start(1).pause(2).stop(3).replay
# >> starting in 1
# >> pausing in 2
# >> stopping in 3