class Mirror
  def echo
    print "enter something: "
    response = gets.chomp
    puts "#{response}"
  end
end

require 'rspec'

describe Mirror do
  it "should echo" do
    @mirror = Mirror.new
    @mirror.stub!(:gets) { "phrase\n" }
    @mirror.should_receive(:puts).with("phrase")
    @mirror.echo
  end
end