all the little things (railsconf)

@sandimetz Apr 2014 sandi metz all the little things 1
Thursday, April 24, 14

@sandimetz Apr 2014 Want better apps? 2 Thursday, April 24,
14

@sandimetz Apr 2014 make smaller things 3 Thursday, April 24,
14

@sandimetz Apr 2014 The Gilded Rose Kata 4 Thursday, April
24, 14

@sandimetz Apr 2014 class GildedRose attr_reader :name, :quality, :days_remaining
def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick # ... end end 5 Thursday, April 24, 14

@sandimetz Apr 2014 def tick if
@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end # 21 more lines def tick if name != 'Aged Brie' && name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if quality < 50 @quality += 1 if name == 'Backstage passes to a TAFKAL80ETC concert' if days_remaining < 11 if quality < 50 @quality += 1 end end if days_remaining < 6 if quality < 50 @quality += 1 end end end end end if name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if days_remaining < 0 if name != "Aged Brie" if name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = quality -‐ quality end else if quality < 50 @quality += 1 end end end end end 6 Thursday, April 24, 14

@sandimetz Apr 2014 def tick #
22 previous lines if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end def tick if name != 'Aged Brie' && name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if quality < 50 @quality += 1 if name == 'Backstage passes to a TAFKAL80ETC concert' if days_remaining < 11 if quality < 50 @quality += 1 end end if days_remaining < 6 if quality < 50 @quality += 1 end end end end end if name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if days_remaining < 0 if name != "Aged Brie" if name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = quality -‐ quality end else if quality < 50 @quality += 1 end end end end end 7 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 8 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 44.7 0 25 50 big conditional Complexity (Flog) 9 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 44.7 0 25 50 big conditional Complexity (Flog) 50 9 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 44.7 0 25 50 big conditional Complexity (Flog) 45 tick 50 9 Thursday, April 24, 14

@sandimetz Apr 2014 11 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end Squint Test 12 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end changes in shape 13 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 2 14 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end changes in color 15 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 16 if statements 17 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 16 if statements 7 != 17 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 16 if statements 7 != 2 != with && 17 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 16 if statements 7 != 2 != with && 3 magic strings 17 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end 16 if statements 7 != 2 != with && 3 magic strings ? magic numbers 17 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end magic strings 18 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end ‘Aged Brie’ magic strings 18 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end ‘Aged Brie’ ‘Sulfuras, Hand of Ragnaros’ magic strings 18 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end ‘Aged Brie’ ‘Sulfuras, Hand of Ragnaros’ ‘Backstage passes to a TAFKAL80ETC concert’ magic strings 18 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end it has tests 19 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: S..S.S...S..........S....S..... Fabulous run in 0.002800s,
11071.4286 runs/s, 17857.1429 assertions/s. 31 runs, 50 assertions, 0 failures, 0 errors, 6 skips 20 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRoseTest < Minitest::Test def test_normal_item_before_sell_date
def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound def test_backstage_pass_very_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_lower_bound def test_backstage_pass_very_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_on_sell_date def test_backstage_pass_after_sell_date 21 Thursday, April 24, 14

def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound def test_backstage_pass_very_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_lower_bound def test_backstage_pass_very_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_on_sell_date def test_backstage_pass_after_sell_date brie 21 Thursday, April 24, 14

def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound def test_backstage_pass_very_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_lower_bound def test_backstage_pass_very_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_on_sell_date def test_backstage_pass_after_sell_date brie sulfuras 21 Thursday, April 24, 14

def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound def test_backstage_pass_very_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_lower_bound def test_backstage_pass_very_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_on_sell_date def test_backstage_pass_after_sell_date brie sulfuras backstage pass 21 Thursday, April 24, 14

def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound def test_backstage_pass_very_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_lower_bound def test_backstage_pass_very_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_on_sell_date def test_backstage_pass_after_sell_date brie sulfuras backstage pass normal 21 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound let’s look at a test 22 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound 23 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound name 23 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound name quality 23 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound name quality days_remaining 23 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound 23 Thursday, April 24, 14

item = GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound reduced by 1 24 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRoseTest < Minitest::Test def test_conjured_item_before_sell_date
def test_conjured_item_at_zero_quality def test_conjured_item_on_sell_date def test_conjured_item_on_sell_date_at_zero_quality def test_conjured_item_after_sell_date def test_conjured_item_after_sell_date_at_zero_quality end 25 Thursday, April 24, 14

def test_conjured_item_at_zero_quality def test_conjured_item_on_sell_date def test_conjured_item_on_sell_date_at_zero_quality def test_conjured_item_after_sell_date def test_conjured_item_after_sell_date_at_zero_quality end 6 skipped tests 25 Thursday, April 24, 14

@sandimetz Apr 2014 Task: 27 Thursday, April 24, 14

@sandimetz Apr 2014 Task: Implement Conjured 27 Thursday, April 24,
14

def test_conjured_item_at_zero_quality def test_conjured_item_on_sell_date def test_conjured_item_on_sell_date_at_zero_quality def test_conjured_item_after_sell_date def test_conjured_item_after_sell_date_at_zero_quality end I tried 28 Thursday, April 24, 14

def test_conjured_item_at_zero_quality def test_conjured_item_on_sell_date def test_conjured_item_on_sell_date_at_zero_quality def test_conjured_item_after_sell_date def test_conjured_item_after_sell_date_at_zero_quality end but failed 29 Thursday, April 24, 14

def test_conjured_item_at_zero_quality def test_conjured_item_on_sell_date def test_conjured_item_on_sell_date_at_zero_quality def test_conjured_item_after_sell_date def test_conjured_item_after_sell_date_at_zero_quality end miserably 30 Thursday, April 24, 14

@sandimetz Apr 2014 the pattern failed me 31 Thursday, April
24, 14

@sandimetz Apr 2014 Task: 32 Thursday, April 24, 14

@sandimetz Apr 2014 Task: Refactor code so I can Implement
Conjured 32 Thursday, April 24, 14

def test_normal_item_on_sell_date def test_normal_item_after_sell_date def test_normal_item_of_zero_quality normal 33 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end # .... def tick if name != 'Aged Brie' && name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if quality < 50 @quality += 1 if name == 'Backstage passes to a TAFKAL80ETC concert' if days_remaining < 11 if quality < 50 @quality += 1 end end if days_remaining < 6 if quality < 50 @quality += 1 end end end end end if name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if days_remaining < 0 if name != "Aged Brie" if name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = quality -‐ quality end else if quality < 50 @quality += 1 end end end end end 34 Thursday, April 24, 14

@name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end def tick if name == 'normal' return end if name != 'Aged Brie' && name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if quality < 50 @quality += 1 if name == 'Backstage passes to a TAFKAL80ETC concert' if days_remaining < 11 if quality < 50 @quality += 1 end end if days_remaining < 6 if quality < 50 @quality += 1 end end end end end if name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if days_remaining < 0 if name != "Aged Brie" if name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = quality -‐ quality end else if quality < 50 @quality += 1 end end end end end 35 Thursday, April 24, 14

name == 'normal' return end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end def tick if name == 'normal' return end if name != 'Aged Brie' && name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if quality < 50 @quality += 1 if name == 'Backstage passes to a TAFKAL80ETC concert' if days_remaining < 11 if quality < 50 @quality += 1 end end if days_remaining < 6 if quality < 50 @quality += 1 end end end end end if name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if days_remaining < 0 if name != "Aged Brie" if name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = quality -‐ quality end else if quality < 50 @quality += 1 end end end end end 36 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: .S...S...S..SFF....F.....SS.F.. Fabulous run in 0.020340s,
1524.0905 runs/s, 2310.7178 assertions/s. 1) Failure: GildedRoseTest#test_normal_item_of_zero_quality [gilded_rose_test.rb:37]: Expected: 4 Actual: 5 2) Failure: GildedRoseTest#test_normal_item_before_sell_date [gilded_rose_test.rb:12]: Expected: 9 Actual: 10 3) Failure: GildedRoseTest#test_normal_item_on_sell_date [gilded_rose_test.rb:20]: Expected: 8 Actual: 10 4) Failure: GildedRoseTest#test_normal_item_after_sell_date [gilded_rose_test.rb:28]: Expected: 8 Actual: 10 31 runs, 47 assertions, 4 failures, 0 errors, 6 skips 37 Thursday, April 24, 14

1524.0905 runs/s, 2310.7178 assertions/s. 1) Failure: GildedRoseTest#test_normal_item_of_zero_quality [gilded_rose_test.rb:37]: Expected: 4 Actual: 5 2) Failure: GildedRoseTest#test_normal_item_before_sell_date [gilded_rose_test.rb:12]: Expected: 9 Actual: 10 3) Failure: GildedRoseTest#test_normal_item_on_sell_date [gilded_rose_test.rb:20]: Expected: 8 Actual: 10 4) Failure: GildedRoseTest#test_normal_item_after_sell_date [gilded_rose_test.rb:28]: Expected: 8 Actual: 10 31 runs, 47 assertions, 4 failures, 0 errors, 6 skips 4 failures 37 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def tick
if name == 'normal' return end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end end 38 Thursday, April 24, 14

if name == 'normal' return end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end def normal_tick end end 39 Thursday, April 24, 14

if name == 'normal' return normal_tick end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end def normal_tick end end 40 Thursday, April 24, 14

1524.0905 runs/s, 2310.7178 assertions/s. 1) Failure: GildedRoseTest#test_normal_item_of_zero_quality [gilded_rose_test.rb:37]: Expected: 4 Actual: 5 2) Failure: GildedRoseTest#test_normal_item_before_sell_date [gilded_rose_test.rb:12]: Expected: 9 Actual: 10 3) Failure: GildedRoseTest#test_normal_item_on_sell_date [gilded_rose_test.rb:20]: Expected: 8 Actual: 10 4) Failure: GildedRoseTest#test_normal_item_after_sell_date [gilded_rose_test.rb:28]: Expected: 8 Actual: 10 31 runs, 47 assertions, 4 failures, 0 errors, 6 skips 4 failures 41 Thursday, April 24, 14

@sandimetz Apr 2014 def test_normal_item_before_sell_date item
= GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end 42 Thursday, April 24, 14

= GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end class GildedRose # ... def normal_tick end end 43 Thursday, April 24, 14

= GildedRose.new('normal', 10, 5) item.tick assert_equal 9, item.quality assert_equal 4, item.days_remaining end class GildedRose # ... def normal_tick @quality -‐= 1 @days_remaining -‐= 1 end end 44 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: .....S...FS....FS.S...FS....S.. Fabulous run in 0.029178s,
1062.4443 runs/s, 1713.6199 assertions/s. 1) Failure: GildedRoseTest#test_normal_item_of_zero_quality [gilded_rose_test.rb:38]: Expected: 0 Actual: -‐1 2) Failure: GildedRoseTest#test_normal_item_after_sell_date [gilded_rose_test.rb:30]: Expected: 8 Actual: 9 3) Failure: GildedRoseTest#test_normal_item_on_sell_date [gilded_rose_test.rb:22]: Expected: 8 Actual: 9 31 runs, 50 assertions, 3 failures, 0 errors, 6 skips 3 failures 45 Thursday, April 24, 14

@sandimetz Apr 2014 def test_normal_item_on_sell_date item
= GildedRose.new('normal', 10, 0) item.tick assert_equal 8, item.quality assert_equal -‐1, item.days_remaining end class GildedRose # ... def normal_tick @quality -‐= 1 @days_remaining -‐= 1 end end 46 Thursday, April 24, 14

= GildedRose.new('normal', 10, 0) item.tick assert_equal 8, item.quality assert_equal -‐1, item.days_remaining end class GildedRose # ... def normal_tick @quality -‐= 1 @days_remaining -‐= 1 end end 47 Thursday, April 24, 14

= GildedRose.new('normal', 10, 0) item.tick assert_equal 8, item.quality assert_equal -‐1, item.days_remaining end class GildedRose # ... def normal_tick if @days_remaining > 0 @quality -‐= 1 end @days_remaining -‐= 1 end end 48 Thursday, April 24, 14

= GildedRose.new('normal', 10, 0) item.tick assert_equal 8, item.quality assert_equal -‐1, item.days_remaining end class GildedRose # ... def normal_tick if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end @days_remaining -‐= 1 end end 49 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: ...S.S.....S..S..SF.....S...... Fabulous run in 0.019924s,
1555.9125 runs/s, 2459.3455 assertions/s. 1) Failure: GildedRoseTest#test_normal_item_of_zero_quality [gilded_rose_test.rb:37]: Expected: 0 Actual: -‐1 31 runs, 49 assertions, 1 failures, 0 errors, 6 skips 1 failure ?? 50 Thursday, April 24, 14

@sandimetz Apr 2014 def test_normal_item_of_zero_quality item
= GildedRose.new('normal', 0, 5) item.tick assert_equal 0, item.quality assert_equal 4, item.days_remaining end class GildedRose # ... def normal_tick if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end @days_remaining -‐= 1 end end 51 Thursday, April 24, 14

= GildedRose.new('normal', 0, 5) item.tick assert_equal 0, item.quality assert_equal 4, item.days_remaining end class GildedRose # ... def normal_tick if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end @days_remaining -‐= 1 end end 52 Thursday, April 24, 14

= GildedRose.new('normal', 0, 5) item.tick assert_equal 0, item.quality assert_equal 4, item.days_remaining end class GildedRose # ... def normal_tick if @quality != 0 if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end @days_remaining -‐= 1 end end 53 Thursday, April 24, 14

@sandimetz Apr 2014 refactor under green 55 Thursday, April 24,
14

@sandimetz Apr 2014 reach for the lowest hanging green 56

@sandimetz Apr 2014 def normal_tick if
@quality != 0 if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end @days_remaining -‐= 1 end 57 Thursday, April 24, 14

@sandimetz Apr 2014 def normal_tick end def
normal_tick if @quality != 0 if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end @days_remaining -‐= 1 end 58 Thursday, April 24, 14

@sandimetz Apr 2014 def normal_tick @days_remaining
-‐= 1 end def normal_tick if @quality != 0 if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end @days_remaining -‐= 1 end 59 Thursday, April 24, 14

-‐= 1 end def normal_tick if @quality != 0 if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end end 60 Thursday, April 24, 14

-‐= 1 return if @quality == 0 end def normal_tick if @quality != 0 if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end end 61 Thursday, April 24, 14

-‐= 1 return if @quality == 0 end def normal_tick if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end 62 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 end def normal_tick if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end 63 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def normal_tick if @days_remaining > 0 @quality -‐= 1 end if @days_remaining <= 0 @quality -‐= 2 end end 64 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def normal_tick end 65 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end 66 Thursday, April 24, 14

if name == 'normal' return normal_tick end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end end Reprise 68 Thursday, April 24, 14

if name == 'normal' return normal_tick end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end end 69 Thursday, April 24, 14

if name == 'normal' return normal_tick end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 70 Thursday, April 24, 14

if name == 'normal' return normal_tick end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' # ... 40 more lines end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end normal 70 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRoseTest < Minitest::Test # def test_normal
... etc def test_brie_before_sell_date def test_brie_before_sell_date_with_max_quality def test_brie_on_sell_date def test_brie_on_sell_date_near_max_quality def test_brie_on_sell_date_with_max_quality def test_brie_after_sell_date def test_brie_after_sell_date_with_max_quality # def test_sulfuras ... etc # def test_backstage ... etc end brie 71 Thursday, April 24, 14

@sandimetz Apr 2014 def tick if name
== 'normal' return normal_tick end # ... end 72 Thursday, April 24, 14

@sandimetz Apr 2014 def tick case
name when 'normal' return normal_tick end # ... end 73 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick end # ... end 74 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick end # ... end def brie_tick end 75 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: .F...F.....S.S.F..S.FF.S.F.FS.S Fabulous run in 0.027410s,
1130.9741 runs/s, 1678.2196 assertions/s. 1) Failure: GildedRoseTest#test_brie_on_sell_date_with_max_quality [gilded_rose_test.rb:78]: Expected: 4 Actual: 5 2) Failure: GildedRoseTest#test_brie_on_sell_date_near_max_quality [gilded_rose_test.rb:69]: Expected: 50 Actual: 49 3) Failure: GildedRoseTest#test_brie_on_sell_date [gilded_rose_test.rb:61]: Expected: 12 Actual: 10 4) Failure: GildedRoseTest#test_brie_after_sell_date_with_max_quality [gilded_rose_test.rb:94]: Expected: -‐11 Actual: -‐10 5) Failure: GildedRoseTest#test_brie_before_sell_date_with_max_quality [gilded_rose_test.rb:54]: Expected: 6 Actual: 7 7 failures 76 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick end # ... end def brie_tick end 77 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick end # ... end def brie_tick end fast forward... 77 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick end # ... end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end 78 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick end # ... end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end brie 78 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: ...S......S.....SS.....SS...... Fabulous run in 0.003862s,

@sandimetz Apr 2014 def normal_tick @days_remaining -‐=
1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end Similarity 80 Thursday, April 24, 14

@sandimetz Apr 2014 def normal_tick @days_remaining -‐=
1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end 81 Thursday, April 24, 14

@sandimetz Apr 2014 duplication is far cheaper than the wrong
abstraction 82 Thursday, April 24, 14

... etc # def test_brie ... etc def test_sulfuras_before_sell_date def test_sulfuras_on_sell_date def test_sulfuras_after_sell_date # def test_backstage ... etc end sulfuras 83 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick when 'Sulfuras, Hand of Ragnaros' return sulfuras_tick end # ... end def sulfuras_tick end 84 Thursday, April 24, 14

8026.9291 runs/s, 12946.6598 assertions/s. 31 runs, 50 assertions, 0 failures, 0 errors, 6 skips 0 failures ?!? 85 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick when 'Sulfuras, Hand of Ragnaros' return sulfuras_tick end # ... end def sulfuras_tick end 86 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick when 'Sulfuras, Hand of Ragnaros' return sulfuras_tick end # ... end def sulfuras_tick end nothing changes 86 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick when 'Sulfuras, Hand of Ragnaros' return sulfuras_tick end # ... end def sulfuras_tick end sulfuras 86 Thursday, April 24, 14

... etc # def test_brie ... etc # def test_sulfuras ... etc def test_backstage_pass_long_before_sell_date def test_backstage_pass_medium_close_to_sell_date_upper_bound def test_backstage_pass_medium_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_medium_close_to_sell_date_lower_bound def test_backstage_pass_medium_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_upper_bound def test_backstage_pass_very_close_to_sell_date_upper_bound_at_max_quality def test_backstage_pass_very_close_to_sell_date_lower_bound def test_backstage_pass_very_close_to_sell_date_lower_bound_at_max_quality def test_backstage_pass_on_sell_date def test_backstage_pass_after_sell_date end backstage 87 Thursday, April 24, 14

name when 'normal' when 'Aged Brie' when 'Sulfuras, Hand of Ragnaros' when 'Backstage passes to a TAFKAL80ETC concert' return backstage_tick end # ... end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end backstage 88 Thursday, April 24, 14

name when 'normal' return normal_tick when 'Aged Brie' return brie_tick when 'Sulfuras, Hand of Ragnaros' return sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' return backstage_tick end if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC c # ... end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick def sulfuras_tick def backstage_tick class GildedRose attr_reader :name, :quality, :days_remaining def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remai end def tick case name when 'normal' return normal_tick when 'Aged Brie' return brie_tick when 'Sulfuras, Hand of Ragnaros' return sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' return backstage_tick end if name != 'Aged Brie' && name != 'Backstage passes to a TAF if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if quality < 50 @quality += 1 if name == 'Backstage passes to a TAFKAL80ETC concert' if days_remaining < 11 if quality < 50 @quality += 1 end end if days_remaining < 6 if quality < 50 @quality += 1 end end end end end if name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if days_remaining < 0 if name != "Aged Brie" if name != 'Backstage passes to a TAFKAL80ETC concert' if quality > 0 if name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = quality -‐ quality end else if quality < 50 @quality += 1 end end end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 90 Thursday, April 24, 14

@sandimetz Apr 2014 small methods are simple 92 Thursday, April
24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end small methods 93 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end class GildedRose attr_reader :name, :quality, :days_remaining def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end end big conditional small methods 94 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 25 50 big conditional Total Complexity 50 95 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 25 50 big conditional small methods tick normal brie backstage other 40 Total Complexity 50 96 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 25 50 big conditional small methods tick normal brie backstage other 12 40 45 Total Complexity 50 96 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end Complexity 50 big conditional 97 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 45 90 Complexity 50 big conditional 97 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 45 90 Complexity 50 84 40 small methods big conditional 10 Refactorings 97 Thursday, April 24, 14

14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end 99 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end def normal_tick 99 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end def normal_tick def brie_tick 99 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end def normal_tick def brie_tick def sulfuras_tick 99 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end def normal_tick def brie_tick def sulfuras_tick def backstage_tick 99 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end def normal_tick def brie_tick def sulfuras_tick def backstage_tick def conjured_tick 99 Thursday, April 24, 14

-‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end def normal_tick def brie_tick def sulfuras_tick def backstage_tick def conjured_tick ??? 99 Thursday, April 24, 14

@sandimetz Apr 2014 the pattern still fails me 100 Thursday,
April 24, 14

@sandimetz Apr 2014 open / closed 101 Thursday, April 24,
14

@sandimetz Apr 2014 open for extension 102 Thursday, April 24,
14

@sandimetz Apr 2014 open for extension closed for modiﬁcation 103

@sandimetz Apr 2014 OO Principles 105 Thursday, April 24, 14

@sandimetz Apr 2014 OO Principles a style guide for arranging
code 106 Thursday, April 24, 14

@sandimetz Apr 2014 they’re screaming to get out 108 Thursday,
April 24, 14

@sandimetz Apr 2014 brie_tick backstage_tick sulfuras_tick normal_tick GildedRose 110 Thursday,
April 24, 14

@sandimetz Apr 2014 Normal brie_tick backstage_tick sulfuras_tick normal_tick GildedRose 111

@sandimetz Apr 2014 tick Normal brie_tick backstage_tick sulfuras_tick normal_tick GildedRose
112 Thursday, April 24, 14

@sandimetz Apr 2014 tick Normal brie_tick backstage_tick sulfuras_tick normal_tick GildedRose

@sandimetz Apr 2014 tick Normal brie_tick backstage_tick sulfuras_tick GildedRose 114

@sandimetz Apr 2014 tick Normal GildedRose brie_tick backstage_tick sulfuras_tick 115

@sandimetz Apr 2014 def normal_tick
@days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end 117 Thursday, April 24, 14

@sandimetz Apr 2014 def tick
@days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end 118 Thursday, April 24, 14

@sandimetz Apr 2014 class Normal def
tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 119 Thursday, April 24, 14

@sandimetz Apr 2014 class Normal def
initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 120 Thursday, April 24, 14

@sandimetz Apr 2014 class Normal attr_reader
:quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 121 Thursday, April 24, 14

@sandimetz Apr 2014 class Normal
attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 122 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def normal_tick
end class Normal attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 123 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) end class Normal attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 124 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) item.tick end class Normal attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end 125 Thursday, April 24, 14

@sandimetz Apr 2014 normal is an object 127 Thursday, April
24, 14

@sandimetz Apr 2014 brie/sulfuras/backstage are not 128 Thursday, April 24,
14

@item = Normal.new(quality, days_remaining) item.tick end 129 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) item.tick end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end 130 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) item.tick end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def quality end def days_remaining end 131 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) item.tick end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def quality return item.quality if item end def days_remaining end 132 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) item.tick end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def quality return item.quality if item @quality end def days_remaining end 133 Thursday, April 24, 14

@item = Normal.new(quality, days_remaining) item.tick end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def quality return item.quality if item @quality end def days_remaining return item.days_remaining if item @days_remaining end 134 Thursday, April 24, 14

@sandimetz Apr 2014 brie 135 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def brie_tick
@days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end 136 Thursday, April 24, 14

@days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end class Brie end 137 Thursday, April 24, 14

@days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end class Brie def tick end end 138 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def brie_tick end
class Brie def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end 139 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def brie_tick end
class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end 140 Thursday, April 24, 14

@item = Brie.new(quality, days_remaining) item.tick end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end 141 Thursday, April 24, 14

@sandimetz Apr 2014 sulfuras 142 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def sulfuras_tick end

class Sulfuras attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end 144 Thursday, April 24, 14

class Sulfuras attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end 145 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def sulfuras_tick
@item = Sulfuras.new(quality, days_remaining) item.tick end class Sulfuras attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end 146 Thursday, April 24, 14

@sandimetz Apr 2014 backstage 147 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def backstage_tick
@days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end 148 Thursday, April 24, 14

@days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end class Backstage def tick end 149 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose def backstage_tick end
class Backstage def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end 150 Thursday, April 24, 14

class Backstage attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end 151 Thursday, April 24, 14

@item = Backstage.new(quality, days_remaining) item.tick end class Backstage attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end 154 Thursday, April 24, 14

@sandimetz Apr 2014 normal/brie/sulfuras/backstage are now objects 155 Thursday, April
24, 14

@sandimetz Apr 2014 GildedRose tick Normal tick Brie tick Sulfuras
attr_reader :item tick Backstage attr_reader :quality, :days_remaining 156 Thursday, April 24, 14

case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @item = Normal.new(quality, days_remaining) item.tick end def brie_tick @item = Brie.new(quality, days_remaining) item.tick end # etc 157 Thursday, April 24, 14

@sandimetz Apr 2014 rewind 158 Thursday, April 24, 14

case name when 'normal' when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @item = Normal.new(quality, days_remaining) item.tick end def brie_tick @item = Brie.new(quality, days_remaining) item.tick end # etc 161 Thursday, April 24, 14

case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick end def brie_tick @item = Brie.new(quality, days_remaining) item.tick end # etc 162 Thursday, April 24, 14

case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def brie_tick @item = Brie.new(quality, days_remaining) item.tick end # etc 163 Thursday, April 24, 14

case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def brie_tick @item = Brie.new(quality, days_remaining) item.tick end # etc 164 Thursday, April 24, 14

case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' when 'Sulfuras, Hand of Ragnaros' when 'Backstage passes to a TAFKAL80ETC concert' end end def brie_tick @item = Brie.new(quality, days_remaining) item.tick end # etc 165 Thursday, April 24, 14

case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' @item = Brie.new(quality, days_remaining) item.tick when 'Sulfuras, Hand of Ragnaros' @item = Sulfuras.new(quality, days_remaining) item.tick when 'Backstage passes to a TAFKAL80ETC concert' @item = Backstage.new(quality, days_remaining) item.tick end end 166 Thursday, April 24, 14

@sandimetz Apr 2014 abstract away the duplication 167 Thursday, April
24, 14

@sandimetz Apr 2014 class GildedRose attr_reader :name, :item
def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' @item = Brie.new(quality, days_remaining) item.tick when 'Sulfuras, Hand of Ragnaros' @item = Sulfuras.new(quality, days_remaining) item.tick when 'Backstage passes to a TAFKAL80ETC concert' @item = Backstage.new(quality, days_remaining) item.tick end end 170 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @item = ??? end def tick case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' @item = Brie.new(quality, days_remaining) item.tick when 'Sulfuras, Hand of Ragnaros' @item = Sulfuras.new(quality, days_remaining) item.tick when 'Backstage passes to a TAFKAL80ETC concert' @item = Backstage.new(quality, days_remaining) item.tick end end 171 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @item = ???.new(quality, days_remaining) end def tick case name when 'normal' @item = Normal.new(quality, days_remaining) item.tick when 'Aged Brie' @item = Brie.new(quality, days_remaining) item.tick when 'Sulfuras, Hand of Ragnaros' @item = Sulfuras.new(quality, days_remaining) item.tick when 'Backstage passes to a TAFKAL80ETC concert' @item = Backstage.new(quality, days_remaining) item.tick end end 172 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @item = ???.new(quality, days_remaining) end def case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Sulfuras when 'Backstage passes to a TAFKAL80ETC concert' Backstage end 173 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @item = ???.new(quality, days_remaining) end def case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Sulfuras when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 174 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @item = ???.new(quality, days_remaining) end def klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Sulfuras when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 175 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Sulfuras when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 176 Thursday, April 24, 14

@sandimetz Apr 2014 class GildedRose attr_reader :item def
initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Sulfuras when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 177 Thursday, April 24, 14

initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end 178 Thursday, April 24, 14

initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end def tick item.tick end 179 Thursday, April 24, 14

initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end def tick item.tick end def quality return item.quality if item @quality end def days_remaining return item.days_remaining if item @days_remaining end 180 Thursday, April 24, 14

initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end def tick item.tick end def quality return item.quality if item end def days_remaining return item.days_remaining if item end 181 Thursday, April 24, 14

initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end 182 Thursday, April 24, 14

initialize(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end 183 Thursday, April 24, 14

@sandimetz Apr 2014 item is a role 184 Thursday, April
24, 14

@sandimetz Apr 2014 GildedRose tick Normal tick Brie tick Sulfuras
attr_reader :item tick Backstage attr_reader :quality, :days_remaining 185 Thursday, April 24, 14

@sandimetz Apr 2014 attr_reader :item GildedRose ItemRole def tick
def quality def days_remaining 186 Thursday, April 24, 14

@sandimetz Apr 2014 attr_reader :item ItemRole def tick def
quality def days_remaining GildedRose 187 Thursday, April 24, 14

@sandimetz Apr 2014 attr_reader :item def tick end def quality
end def days_remaining end ItemRole def tick def quality def days_remaining GildedRose 187 Thursday, April 24, 14

@sandimetz Apr 2014 attr_reader :item def tick item.tick end
def quality item.quality end def days_remaining item.days_remaining end GildedRose ItemRole def tick def quality def days_remaining 188 Thursday, April 24, 14

@sandimetz Apr 2014 Foo def tick item.tick end def
quality item.quality end def days_remaining item.days_remaining end attr_reader :item GildedRose ItemRole def tick def quality def days_remaining 189 Thursday, April 24, 14

quality item.quality end def days_remaining item.days_remaining end attr_reader :item attr_reader :rose GildedRose ItemRole def tick def quality def days_remaining 189 Thursday, April 24, 14

quality item.quality end def days_remaining item.days_remaining end attr_reader :item attr_reader :rose def doit rose.tick rose.quality rose.days_remaining end GildedRose ItemRole def tick def quality def days_remaining 189 Thursday, April 24, 14

quality item.quality end def days_remaining item.days_remaining end attr_reader :item attr_reader :rose def doit rose.tick rose.quality rose.days_remaining end GildedRose ItemRole def tick def quality def days_remaining 190 Thursday, April 24, 14

quality item.quality end def days_remaining item.days_remaining end attr_reader :item attr_reader :rose def doit rose.tick rose.quality rose.days_remaining end GildedRose ItemRole def tick def quality def days_remaining Middleman 190 Thursday, April 24, 14

@sandimetz Apr 2014 Foo attr_reader :item attr_reader :rose GildedRose ItemRole
def tick def quality def days_remaining 191 Thursday, April 24, 14

@sandimetz Apr 2014 Foo attr_reader :item attr_reader :rose def getit
@rose = GildedRose.new( ‘normal’, ...) end GildedRose ItemRole def tick def quality def days_remaining 191 Thursday, April 24, 14

@sandimetz Apr 2014 Foo def initialize(name,...) @item =
klass_for(name). new( quality, days_remaining) end def klass_for(name) case name when 'normal' Normal attr_reader :item attr_reader :rose def getit @rose = GildedRose.new( ‘normal’, ...) end GildedRose ItemRole def tick def quality def days_remaining 191 Thursday, April 24, 14

@sandimetz Apr 2014 Foo def initialize(name,...) @item =
klass_for(name). new( quality, days_remaining) end def klass_for(name) case name when 'normal' Normal attr_reader :item attr_reader :rose def getit @rose = GildedRose.new( ‘normal’, ...) end GildedRose ItemRole def tick def quality def days_remaining Item Factory 191 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose attr_reader :item def

self.for(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end 194 Thursday, April 24, 14

self.for(name, quality, days_remaining) @item = klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end 195 Thursday, April 24, 14

self.for(name, quality, days_remaining) klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end 196 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose def self.for(name, quality, days_remaining)
klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end 197 Thursday, April 24, 14

klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end 198 Thursday, April 24, 14

klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end def tick item.tick end def quality item.quality end def days_remaining item.days_remaining end class Normal class Brie class Sulfuras class Backstage end Middleman 198 Thursday, April 24, 14

klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end class Normal class Brie class Sulfuras class Backstage end 199 Thursday, April 24, 14

@sandimetz Apr 2014 Foo def self.for(name,...) end attr_reader :rose def
getit @rose = GildedRose.for( ‘normal’, ...) end GildedRose 200 Thursday, April 24, 14

@sandimetz Apr 2014 Foo attr_reader :rose def getit @rose
= GildedRose.for( ‘normal’, ...) end ItemRole def tick def quality def days_remaining def self.for(name,...) end GildedRose 201 Thursday, April 24, 14

@sandimetz Apr 2014 extract common code 202 Thursday, April 24,
14

klass_for(name).new(quality, days_remaining) end def self.klass_for(name) # ... end class Normal class Brie class Sulfuras class Backstage end 203 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose class Normal
attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end 204 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end 205 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick 206 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose class Item end
class Normal attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick 207 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose class Item
attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal def tick # ... end end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick 208 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick 209 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end 210 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick # ... end end 211 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end 212 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end class Sulfuras < Item def tick end end class Backstage < Item def tick 213 Thursday, April 24, 14

@sandimetz Apr 2014 inheritance is not evil 214 Thursday, April
24, 14

@sandimetz Apr 2014 but we sometimes are 215 Thursday, April
24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end class Sulfuras < Item def tick end end class Backstage < Item def tick 216 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end class Sulfuras < Item def tick end end class Backstage < Item def tick Item quality days_remaining 216 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end class Sulfuras < Item def tick end end class Backstage < Item def tick Item quality days_remaining Normal Brie Sulfuras Backstage quality days_remaining tick 216 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end class Sulfuras < Item def tick end end 217 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick # ... end end class Brie < Item def tick # ... end end class Sulfuras < Item def tick end end 218 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Sulfuras < Item def tick end end 219 Thursday, April 24, 14

def tick end end class Sulfuras < Item def tick end end 220 Thursday, April 24, 14

def tick end end class Sulfuras < Item def tick end end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Sulfuras when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 221 Thursday, April 24, 14

def tick end end class Sulfuras < Item def tick end end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 222 Thursday, April 24, 14

def tick end end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end 223 Thursday, April 24, 14

@sandimetz Apr 2014 extract conﬁguration 226 Thursday, April 24, 14

klass_for(name).new(quality, days_remaining) end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end end 227 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose DEFAULT_CLASS = Item
SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) klass_for(name).new(quality, days_remaining) end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end end 228 Thursday, April 24, 14

SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) klass_for(name).new(quality, days_remaining) end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end end 229 Thursday, April 24, 14

SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) klass_for(name). new(quality, days_remaining) end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end end 230 Thursday, April 24, 14

SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS). new(quality, days_remaining) end def self.klass_for(name) case name when 'normal' Normal when 'Aged Brie' Brie when 'Sulfuras, Hand of Ragnaros' Item when 'Backstage passes to a TAFKAL80ETC concert' Backstage end end end 231 Thursday, April 24, 14

SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS). new(quality, days_remaining) end end 232 Thursday, April 24, 14

@sandimetz Apr 2014 small objects 233 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end module GildedRose class Item attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, end end 234 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose class Brie < Item
def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end module GildedRose class Item attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, end end 235 Thursday, April 24, 14

SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS). new(quality, days_remaining) end end module GildedRose class Item attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, end end 236 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remainin end end small objects 237 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remainin end end small objects class GildedRose attr_reader :name, :quality, :days_remaining def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else if @quality < 50 @quality += 1 if @name == 'Backstage passes to a TAFKAL80ETC concert' if @days_remaining < 11 if @quality < 50 @quality += 1 end end if @days_remaining < 6 if @quality < 50 @quality += 1 end end end end end if @name != 'Sulfuras, Hand of Ragnaros' @days_remaining -‐= 1 end if @days_remaining < 0 if @name != "Aged Brie" if @name != 'Backstage passes to a TAFKAL80ETC concert' if @quality > 0 if @name != 'Sulfuras, Hand of Ragnaros' @quality -‐= 1 end end else @quality = @quality -‐ @quality end else if @quality < 50 @quality += 1 end end end end end big conditional 238 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remainin end end small methods class GildedRose attr_reader :name, :quality, :days_remaining def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end small objects 239 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 big conditional small methods small objects tick/for normal brie backstage other Total Complexity 40 50 240 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 big conditional small methods small objects tick/for normal brie backstage other 33 40 50 Total Complexity 241 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end big conditional small methods small objects 50 84 40 Total Complexity 242 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 45 90 big conditional small methods small objects 50 84 40 Total Complexity 242 Thursday, April 24, 14

def initialize(name, quality, days_remaining) @name, @quality, @days_remaining = name, quality, days_remaining end def tick case name when 'normal' normal_tick when 'Aged Brie' brie_tick when 'Sulfuras, Hand of Ragnaros' sulfuras_tick when 'Backstage passes to a TAFKAL80ETC concert' backstage_tick end end def normal_tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end def brie_tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end def sulfuras_tick end def backstage_tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end 0 45 90 big conditional small methods small objects 50 84 40 33 86 Total Complexity 242 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 big cond small meth small objs tick/for normal brie backstage other 33 Complexity 40 50 243 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose small meth small objs tick/for normal brie backstage other 33 Complexity 40 50 244 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose GildedRose(2) small objs tick/for normal brie backstage other 33 Complexity 40 50 245 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose GildedRose(2) many objs tick/for normal brie backstage other 33 Complexity 40 50 246 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose GildedRose(2) many objs Backstage tick/for normal brie backstage other 33 Complexity 40 50 12 247 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose GildedRose(2) many objs Backstage average tick/for normal brie backstage other 33 Complexity 40 50 7 12 248 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose Backstage Complexity 50 12 249 Thursday, April 24, 14

attr_reader :quality, :days_remaining def initialize(quality, days_remaining) @quality, @days_remaining = quality, days_remaining end def tick end end class Normal < Item def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 1 @quality -‐= 1 if @days_remaining <= 0 end end class Brie < Item def tick @days_remaining -‐= 1 return if @quality >= 50 @quality += 1 @quality += 1 if @days_remaining <= 0 end end class Backstage < Item def tick @days_remaining -‐= 1 return if @quality >= 50 return @quality = 0 if @days_remaining < 0 @quality += 1 @quality += 1 if @days_remaining < 10 @quality += 1 if @days_remaining < 5 end end DEFAULT_CLASS = Item SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage } def self.for(name, quality, days_remaining) (SPECIALIZED_CLASSES[name] || DEFAULT_CLASS).new(quality, days_remaining) end end 0 25 50 GildedRose Backstage Complexity 50 12 75% 249 Thursday, April 24, 14

14

@sandimetz Apr 2014 module GildedRose 251 Thursday, April 24, 14

@sandimetz Apr 2014 module GildedRose class Conjured < Item
def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 2 @quality -‐= 2 if @days_remaining <= 0 end end 252 Thursday, April 24, 14

def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 2 @quality -‐= 2 if @days_remaining <= 0 end end SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage} 253 Thursday, April 24, 14

def tick @days_remaining -‐= 1 return if @quality == 0 @quality -‐= 2 @quality -‐= 2 if @days_remaining <= 0 end end SPECIALIZED_CLASSES = { 'normal' => Normal, 'Aged Brie' => Brie, 'Backstage passes to a TAFKAL80ETC concert' => Backstage, 'Conjured Mana Cake' => Conjured } 254 Thursday, April 24, 14

@sandimetz Apr 2014 # Running: ............................... Fabulous run in 0.003917s,

@sandimetz Apr 2014 Summary 256 Thursday, April 24, 14

@sandimetz Apr 2014 prefer duplication over the wrong abstraction 257

@sandimetz Apr 2014 reach for open / closed 258 Thursday,
April 24, 14

@sandimetz Apr 2014 make small things 259 Thursday, April 24,
14

@sandimetz Apr 2014 refactor through complexity 260 Thursday, April 24,
14

@sandimetz Apr 2014 refactor to simplicity 261 Thursday, April 24,
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@sandimetz Apr 2014 love your code 262 Thursday, April 24,
14

@sandimetz Apr 2014 Sandi Metz @sandimetz Apr 2014 263 Thursday,
April 24, 14

@sandimetz Apr 2014 Sandi Metz @sandimetz @sandimetz Apr 2014 263

@sandimetz Apr 2014 Sandi Metz @sandimetz @sandimetz Apr 2014 http://sandimetz.com

http://poodr.com Sandi Metz @sandimetz @sandimetz Apr 2014 264 Thursday, April
24, 14

@sandimetz Apr 2014 @sandimetz Apr 2014 http://practicalrailsbook.com 265 Thursday, April
24, 14

@sandimetz Apr 2014 London Course http://kickstartacademy.io/courses/ practical-object-oriented-design June 25-27 July
3-4 266 Thursday, April 24, 14

@sandimetz Apr 2014 Thanks 267 Thursday, April 24, 14

@sandimetz Apr 2014 Thanks Jim 267 Thursday, April 24, 14

@sandimetz Apr 2014 Questions? 268 Thursday, April 24, 14

all the little things (railsconf)

all the little things (railsconf)

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