Simple refactoring exercises and 2 minute commits version - with updated characterisation tests.

refactoring_example.rb

# This is a refactoring exercise.
#
# What to do?
# 
# I. Simple refactoring
#    1. Look at the code of the class CorrectAnswerBehavior
#    2. Try to see what it does by running `ruby refactoring_example.rb` 
#    3. Record characterisation tests by running `ruby refactoring_example.rb --record`
#    4. Make the code beautiful;)
#    5. You are allowed to modify only the code between markers (REFACTORING START/REFACTORING END).
#    6. Test must pass! You can run them with command `ruby refactoring_example.rb --record`
#    7. For suggestions of other exercises based on this code...
#        a) Follow http://twitter.com/programmingwod or
#        b) like https://www.facebook.com/ProgrammingWorkout or
#        c) signup to http://programmingworkout.com
#
# II. Two minute commits.
#    1. Same as Simple Refactoring but you work in two minute iterations.
#       a) Start timer. (2 minutes)
#       b) Refactor.
#       c) Commit if tests pass.
#       d) Revert all uncommitted changes when timer rings. NO EXCEPTIONS!!!
#       e) Repeat
#
# III. Refactor moar!
#   1. You are now allowed to refactor code between markers (REFACTORING START/REFACTORING END 2).
#   2. Tests with fixtures before refactoring need to pass.
#   3. Does it change anything for you? Hint: You can add some code outside CorrectAnswerBehavior class.
#    
# Usage:
#  ruby refactoring_example.rb [-h|--help|help]       - shows help screen.
#  ruby refactoring_example.rb [-c|--clean|clean]     - clean recorded results of simulation.
#  ruby refactoring_example.rb [-r|--record|record]   - records 5000 results of simulation.
#  ruby refactoring_example.rb [-t|--test|test]       - tests against 5000 recorded results of simulation.
#  ruby refactoring_example.rb <ANY_NUMBER>           - shows result of simulation initialized with <ANY_NUMBER>.
#  ruby refactoring_example.rb                        - shows result of random simulation.
# 
# License: MIT (see at the end of the file)
# This code is based on Trivia Game example used in Legacy Code Retreats
# You can find it at https://github.com/jbrains/trivia

# ------------------------------ REFACTORING START ------------------------------
class CorrectAnswerBehavior

  def was_correctly_answered
    if @in_penalty_box[@current_player]
      if @is_getting_out_of_penalty_box
        puts "#{@players[@current_player]} got out of penalty box"
        puts 'Answer was correct!!!!'
        @purses[@current_player] += 1
        puts "#{@players[@current_player]} now has #{@purses[@current_player]} Gold Coins."
        winner = did_player_win()
        @current_player += 1
        @current_player = 0 if @current_player == @players.length
        puts "Player is now #{@players[@current_player]}"
        winner
      else
        puts "#{@players[@current_player]} stays in penalty box"
        @current_player += 1
        @current_player = 0 if @current_player == @players.length
        puts "Player is now #{@players[@current_player]}"
        true
      end
    else
      puts "Answer was corrent!!!!"
      @purses[@current_player] += 1
      puts "#{@players[@current_player]} now has #{@purses[@current_player]} Gold Coins."
      winner = did_player_win
      @current_player += 1
      @current_player = 0 if @current_player == @players.length
      puts "Player is now #{@players[@current_player]}"
      return winner
    end
  end
private
  def did_player_win
    !(@purses[@current_player] == 6)
  end

# ------------------------------ REFACTORING END ------------------------------

public
  def initialize seed = nil
    srand(seed) if seed
    @players = %w[Alice Bob Cecil]
    @purses = @players.map { rand(3) + 5 }
    @in_penalty_box = @players.map { rand(2) == 0 }
    @current_player = rand(@players.count)
    @is_getting_out_of_penalty_box = @in_penalty_box[@current_player] && rand(2) == 0
  end
end

# ------------------------------ REFACTORING END 2 ------------------------------
require 'fileutils'
module FixtureHandler
  def self.clear_fixtures
    FileUtils.rm_rf(fixtures_dir)
  end

  def self.create_fixture_dir
    FileUtils.mkdir(fixtures_dir)
  end

  def self.write_fixture index, text
    File.open(fixture_path(index), "w") do |file|
      file.write(text)
    end
  end

  def self.fixture_exists? index
    File.exists?(fixture_path(index))
  end

  def self.read_fixture index
    File.read(fixture_path(index))
  end

  def self.fixture_path index
    "#{fixtures_dir}/#{index}.txt"
  end

  def self.fixtures_dir
    "#{File.expand_path(File.dirname(__FILE__))}/fixtures"
  end
end

module StdOutToStringRedirector
  require 'stringio'
  def self.redirect_stdout_to_string
    sio = StringIO.new
    old_stdout, $stdout = $stdout, sio
    yield  
    $stdout = old_stdout 
    sio.string
  end
end

SIMULATIONS_COUNT = 5000
def run_simulation index = nil
  result = CorrectAnswerBehavior.new(index).was_correctly_answered
  puts "result was #{result}"
end

def capture_simulation_output index
  StdOutToStringRedirector.redirect_stdout_to_string do
    run_simulation(index)
  end
end

def clean_fixtures
  FixtureHandler.clear_fixtures
end

def record_fixtures
  SIMULATIONS_COUNT.times do |index|
    raise "You need to clean recorded simulation results first!" if FixtureHandler.fixture_exists?(index)
  end
  FixtureHandler.create_fixture_dir
  SIMULATIONS_COUNT.times do |index|
    FixtureHandler.write_fixture(index, capture_simulation_output(index))
  end
rescue RuntimeError => e
  puts "ERROR!!!"
  puts e.message
end

require 'test/unit/assertions'
include Test::Unit::Assertions
def test_output
  SIMULATIONS_COUNT.times do |index|
    raise "You need to record simulation results first!" unless FixtureHandler.fixture_exists?(index)
    assert_equal(FixtureHandler.read_fixture(index), capture_simulation_output(index))
  end
  puts "OK."
rescue RuntimeError => e
  puts "ERROR!!!"
  puts e.message
end

case ARGV[0].to_s.downcase
when "-h", "--help", "help"
  puts "Usage:"
  puts "  ruby #{__FILE__} [-h|--help|help]       - shows help screen."
  puts "  ruby #{__FILE__} [-c|--clean|clean]     - clean recorded results of simulation."
  puts "  ruby #{__FILE__} [-r|--record|record]   - records #{SIMULATIONS_COUNT} results of simulation."
  puts "  ruby #{__FILE__} [-t|--test|test]       - tests against #{SIMULATIONS_COUNT} recorded results of simulation."
  puts "  ruby #{__FILE__} <ANY_NUMBER>           - shows result of simulation initialized with <ANY_NUMBER>."
  puts "  ruby #{__FILE__}                        - shows result of random simulation."
when "-c", "--clean", "clean"
  clean_fixtures
when "-r", "--record", "record"
  record_fixtures
when "-t", "--test", "test"
  test_output
when /\d(.\d+)?/
  run_simulation ARGV[0].to_f
else 
  run_simulation
end


# Copyright © 2012 Michal Taszycki
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Line 51: s/corrent/correct/ ?

Good catch...

However this is legacy code and a lot of other code (not shown in this exercise) depends on that line being exactly as it is :D

So this is still "valid" behavior and we don't want to change it.
But feel free to encapsulate it and mark it somehow as "interesting".

Have fun.

v1
https://gist.github.com/91018efe22eb688400ad

https://gist.github.com/3149998

also v1 :)
https://gist.github.com/3156747

And this is mine
https://gist.github.com/3161100

I've updated the testing routine. Now it checks for the result of #was_correctly_answered method.

Does your solution still pass?

Remember to record fixtures with unmodified example.

git clone git://gist.github.com/3139247.git
ruby refactoring_example.rb -c
ruby refactoring_example.rb -r

Then paste your solution (between refactoring markers) and test with

ruby refactoring_example.rb -t

Btw take a look at added exercise: Two minute commits:

Rules are simple:

a) Start timer. (2 minutes)
b) Refactor.
c) Commit if tests pass.
d) Revert all uncommitted changes when timer rings. NO EXCEPTIONS!!!

Have fun

Oh. Forgot to add

e) Repeat

e) Repeat

LOL! Naturally.

Here's a quick bash script you can use to see how many seconds between each commit:

#!/bin/bash

function main() {
  revisions | while read rev
  do
    commit=`git log -n1 $rev --format="%h %s"`
    time=`git log -n1 $rev --format="%at"`
    : ${previous:=$time}
    diff=$(expr $time - $previous)
    echo "$commit - $diff seconds"
    previous=$time
  done
}

function revisions() {
  git rev-list --all --reverse 
}

main

Ok, giving this a go with the new characterization tests.
https://gist.github.com/3165421

Ported to Objective-C:
https://github.com/nvln/TriviaRefactoring

Here's _bejo's and my code after a few sprints:
https://github.com/nvln/TriviaRefactoringWithBejo/blob/master/TriviaRefactoring/main.m

Last challenge this week is a simple twist that might potentially make a huge difference.
You can refactor anything between markers (REFACTORING START/REFACTORING END 2).
Feel free to start with your previous refactoring.

you can also treat it as an exercise in exploration of boundaries. Unreasonable number of entities is fine. Try something weird.

I'll be giving it a go probably after Wednesday, but I'm really curious what can be done here.