refactor created factory

elixir/lib/gilded_rose.ex

@@ -1,140 +1,83 @@
 defmodule GildedRose do
 
-  @max_quality 50
-
   def update_quality(items) do
-    Enum.map(items, &update_item_new/1)
+    Enum.map(items, &update_item/1)
   end
 
-  # Passes
+  def update_item(item = %{ name: name }) do
+    cond do
+      PassesHandler.is_handled?(name) ->
+        PassesHandler.handle(item)
 
-  @ticket "Backstage passes to a TAFKAL80ETC concert"
+      BrieHandler.is_handled?(name) ->
-  def update_item_new(item = %{ name: @ticket , sell_in: days }) when days - 1 < 0, do:
+        BrieHandler.handle(item)
-    %{item | sell_in: days - 1, quality: 0 }
 
-  def update_item_new(item = %{ name: @ticket , sell_in: days, quality: quality }) when days - 1 < 5, do:
+      SulfurasHandler.is_handled?(name) -> 
-    %{item | sell_in: days - 1, quality: updated_quality(quality + 3) }
+        SulfurasHandler.handle(item)
 
-  def update_item_new(item = %{ name: @ticket , sell_in: days, quality: quality }) when days - 1 < 10, do:
+      ConjuredHandler.is_handled?(name) ->
-    %{item | sell_in: days - 1, quality: updated_quality(quality + 2) }
+        ConjuredHandler.handle(item)
 
-  def update_item_new(item = %{ name: @ticket , sell_in: days, quality: quality }), do:
+      DefaultHandler.is_handled?(name) ->
-    %{item | sell_in: days - 1, quality: updated_quality(quality + 1) }
+        DefaultHandler.handle(item)
+    end
+  end
+
+  # # Passes
+
+  # @ticket "Backstage passes to a TAFKAL80ETC concert"
+  # def update_item_new(item = %{ name: @ticket , sell_in: days }) when days - 1 < 0, do:
+  #   %{item | sell_in: days - 1, quality: 0 }
+
+  # def update_item_new(item = %{ name: @ticket , sell_in: days, quality: quality }) when days - 1 < 5, do:
+  #   %{item | sell_in: days - 1, quality: updated_quality(quality + 3) }
+
+  # def update_item_new(item = %{ name: @ticket , sell_in: days, quality: quality }) when days - 1 < 10, do:
+  #   %{item | sell_in: days - 1, quality: updated_quality(quality + 2) }
+
+  # def update_item_new(item = %{ name: @ticket , sell_in: days, quality: quality }), do:
+  #   %{item | sell_in: days - 1, quality: updated_quality(quality + 1) }
 
   
-  # Brie
+  # # Brie
 
-  @brie "Aged Brie"
+  # @brie "Aged Brie"
-  def update_item_new(item = %{ name: @brie, sell_in: days, quality: quality }) when  days - 1 < 0,  do:
+  # def update_item_new(item = %{ name: @brie, sell_in: days, quality: quality }) when  days - 1 < 0,  do:
-    %{item | sell_in: days - 1, quality: updated_quality(quality + 2) }
+  #   %{item | sell_in: days - 1, quality: updated_quality(quality + 2) }
 
-  def update_item_new(item = %{ name: @brie, sell_in: days, quality: quality }), do:
+  # def update_item_new(item = %{ name: @brie, sell_in: days, quality: quality }), do:
-    %{item | sell_in: days - 1, quality: updated_quality(quality + 1) }
+  #   %{item | sell_in: days - 1, quality: updated_quality(quality + 1) }
     
 
-  # Legendary
+  # # Legendary
 
-  @sulfuras "Sulfuras, Hand of Ragnaros"
+  # @sulfuras "Sulfuras, Hand of Ragnaros"
-  def update_item_new(item = %{ name: @sulfuras }), do:
+  # def update_item_new(item = %{ name: @sulfuras }), do:
-    %{item | quality: 80 }
+  #   %{item | quality: 80 }
 
 
-  # Conjured
+  # # Conjured
 
-  @conjured "Conjured"
+  # @conjured "Conjured"
-  def update_item_new(item = %{name: @conjured, sell_in: sell_in }) when sell_in - 1 < 0, do:
+  # def update_item_new(item = %{name: @conjured, sell_in: sell_in }) when sell_in - 1 < 0, do:
-    %{item | sell_in: sell_in - 1, quality: updated_quality(item.quality - 4) }
+  #   %{item | sell_in: sell_in - 1, quality: updated_quality(item.quality - 4) }
 
-  def update_item_new(item = %{name: @conjured}), do: 
+  # def update_item_new(item = %{name: @conjured}), do: 
-    %{item | sell_in: item.sell_in - 1, quality: updated_quality(item.quality - 2) }
+  #   %{item | sell_in: item.sell_in - 1, quality: updated_quality(item.quality - 2) }
 
-  # Normal
+  # # Normal
   
-  def update_item_new(item = %{sell_in: sell_in }) when sell_in - 1 < 0, do:
+  # def update_item_new(item = %{sell_in: sell_in }) when sell_in - 1 < 0, do:
-    %{item | sell_in: sell_in - 1, quality: updated_quality(item.quality - 2) }
+  #   %{item | sell_in: sell_in - 1, quality: updated_quality(item.quality - 2) }
 
-  def update_item_new(item), do:
+  # def update_item_new(item), do:
-    %{item | sell_in: item.sell_in - 1, quality: updated_quality(item.quality - 1) }
+  #   %{item | sell_in: item.sell_in - 1, quality: updated_quality(item.quality - 1) }
 
-  # Utils
+  # # Utils
 
-  defp updated_quality(new_amount)
+  # defp updated_quality(new_amount)
-  defp updated_quality(new_amount) when new_amount < 0, do: 0
+  # defp updated_quality(new_amount) when new_amount < 0, do: 0
-  defp updated_quality(new_amount) when new_amount > @max_quality, do: @max_quality
+  # defp updated_quality(new_amount) when new_amount > @max_quality, do: @max_quality
-  defp updated_quality(new_amount), do: new_amount
+  # defp updated_quality(new_amount), do: new_amount
 
-
-  def update_item(item) do
-    item = cond do
-      item.name != "Aged Brie" && item.name != "Backstage passes to a TAFKAL80ETC concert" ->
-        if item.quality > 0 do
-          if item.name != "Sulfuras, Hand of Ragnaros" do
-            %{item | quality: item.quality - 1}
-          else
-            item
-          end
-        else
-          item
-        end
-      true ->
-        cond do
-          item.quality < 50 ->
-            item = %{item | quality: item.quality + 1}
-            cond do
-              item.name == "Backstage passes to a TAFKAL80ETC concert" ->
-                item = cond do
-                  item.sell_in < 11 ->
-                    cond do
-                      item.quality < 50 ->
-                        %{item | quality: item.quality + 1}
-                      true -> item
-                    end
-                  true -> item
-                end
-                cond do
-                  item.sell_in < 6 ->
-                    cond do
-                      item.quality < 50 ->
-                        %{item | quality: item.quality + 1}
-                      true -> item
-                    end
-                  true -> item
-                end
-              true -> item
-            end
-          true -> item
-        end
-    end
-    item = cond do
-      item.name != "Sulfuras, Hand of Ragnaros" ->
-        %{item | sell_in: item.sell_in - 1}
-      true -> item
-    end
-    cond do
-      item.sell_in < 0 ->
-        cond do
-          item.name != "Aged Brie" ->
-            cond do
-              item.name != "Backstage passes to a TAFKAL80ETC concert" ->
-                cond do
-                  item.quality > 0 ->
-                    cond do
-                      item.name != "Sulfuras, Hand of Ragnaros" ->
-                        %{item | quality: item.quality - 1}
-                      true -> item
-                    end
-                  true -> item
-                end
-              true -> %{item | quality: item.quality - item.quality}
-            end
-          true ->
-            cond do
-              item.quality < 50 ->
-                %{item | quality: item.quality + 1}
-              true -> item
-            end
-        end
-      true -> item
-    end
-  end
 end

elixir/lib/guilded_rose/handlers/brie_handler.ex

@@ -0,0 +1,14 @@
+defmodule BrieHandler do
+  alias Utils.Quality
+  @behaviour ItemHandler
+  @item_name "Aged Brie"
+
+  def is_handled?(item_name), do: item_name == @item_name
+
+  def handle(item = %{ name: @item_name, sell_in: days, quality: quality }) when  days - 1 < 0,  do:
+    %{item | sell_in: days - 1, quality: Quality.calculate(quality + 2) }
+
+  def handle(item = %{ name: @item_name, sell_in: days, quality: quality }), do:
+    %{item | sell_in: days - 1, quality: Quality.calculate(quality + 1) }
+ 
+end

elixir/lib/guilded_rose/handlers/conjured_handler.ex

@@ -0,0 +1,14 @@
+defmodule ConjuredHandler do
+  alias Utils.Quality
+  @behaviour ItemHandler
+  @item_name "Conjured"
+
+  def is_handled?(item_name), do: item_name == @item_name
+
+  def handle(item = %{name: @item_name, sell_in: sell_in }) when sell_in - 1 < 0, do:
+    %{item | sell_in: sell_in - 1, quality: Quality.calculate(item.quality - 4) }
+
+  def handle(item = %{name: @item_name}), do: 
+    %{item | sell_in: item.sell_in - 1, quality: Quality.calculate(item.quality - 2) }
+
+end

elixir/lib/guilded_rose/handlers/default_handler.ex

@@ -0,0 +1,13 @@
+defmodule DefaultHandler do
+  alias Utils.Quality
+  @behaviour ItemHandler
+
+  def is_handled?(item_name), do: true
+    
+  def handle(item = %{ sell_in: sell_in }) when sell_in - 1 < 0, do:
+    %{item | sell_in: sell_in - 1, quality: Quality.calculate(item.quality - 2) }
+
+  def handle(item), do:
+    %{item | sell_in: item.sell_in - 1, quality: Quality.calculate(item.quality - 1) }
+
+end

elixir/lib/guilded_rose/handlers/passes_handler.ex

@@ -0,0 +1,20 @@
+defmodule PassesHandler do
+  alias Utils.Quality
+  @behaviour ItemHandler
+  @item_name "Backstage passes to a TAFKAL80ETC concert"
+
+  def is_handled?(item_name), do: item_name == @item_name
+
+  def handle(item = %{ name: @item_name , sell_in: days }) when days - 1 < 0, do:
+    %{item | sell_in: days - 1, quality: 0 }
+
+  def handle(item = %{ name: @item_name , sell_in: days, quality: quality }) when days - 1 < 5, do:
+    %{item | sell_in: days - 1, quality: Quality.calculate(quality + 3) }
+
+  def handle(item = %{ name: @item_name , sell_in: days, quality: quality }) when days - 1 < 10, do:
+    %{item | sell_in: days - 1, quality: Quality.calculate(quality + 2) }
+
+  def handle(item = %{ name: @item_name , sell_in: days, quality: quality }), do:
+    %{item | sell_in: days - 1, quality: Quality.calculate(quality + 1) }
+
+end

elixir/lib/guilded_rose/handlers/sulfuras_handler.ex

@@ -0,0 +1,10 @@
+defmodule SulfurasHandler do
+  @behaviour ItemHandler
+  @item_name "Sulfuras, Hand of Ragnaros"
+
+  def is_handled?(item_name), do: item_name == @item_name
+
+  def handle(item = %{ name: @item_name }), do:
+    %{item | quality: 80 }
+
+end

elixir/lib/guilded_rose/item_handler.ex

@@ -0,0 +1,4 @@
+defmodule ItemHandler do
+  @callback handle(Item) :: Item
+  @callback is_handled?(String.t()) :: boolean()
+end

elixir/lib/guilded_rose/utils/quality.ex

@@ -0,0 +1,8 @@
+defmodule Utils.Quality do
+
+  def calculate(amount, max \\ 50)
+  def calculate(amount, _) when amount < 0, do: 0
+  def calculate(amount, max) when amount > max, do: max
+  def calculate(amount, _), do: amount
+
+end

elixir/test/gilded_rose_test.exs

@@ -39,6 +39,8 @@ defmodule GildedRoseTest do
     ]
   end
 
+  # Normal items
+
   test "normal item quality _ any day greater than 0" do
     days_left = 10
     initial_quality = 10
@@ -71,6 +73,7 @@ defmodule GildedRoseTest do
     assert normal === %Item{name: @normal, sell_in: -4, quality: 0}
   end
   
+  # Conjured items
 
   test "conjured item quality _ any day greater than 0" do
     days_left = 10
@@ -104,29 +107,35 @@ defmodule GildedRoseTest do
     assert conjured === %Item{name: @conjured, sell_in: -4, quality: 0}
   end
 
-  test "ticket quality _ 10 days or less" do
+
+  # Passes
+
+
+  test "passes quality _ 10 days or less" do
     days_left = 10
     initial_quality = 0
-    [_, ticket, _, _, _] = create_items(days_left, initial_quality) |> elapse_days(1)
+    [_, passes, _, _, _] = create_items(days_left, initial_quality) |> elapse_days(1)
 
-    assert ticket === %Item{name: @passes, sell_in: 9, quality: 2}
+    assert passes === %Item{name: @passes, sell_in: 9, quality: 2}
   end
 
-  test "ticket quality _ 5 days or less" do
+  test "passes quality _ 5 days or less" do
     days_left = 5
     initial_quality = 0
-    [_, ticket, _, _, _] = create_items(days_left, initial_quality) |> elapse_days(1)
+    [_, passes, _, _, _] = create_items(days_left, initial_quality) |> elapse_days(1)
 
-    assert ticket === %Item{name: @passes, sell_in: 4, quality: 3}
+    assert passes === %Item{name: @passes, sell_in: 4, quality: 3}
   end
 
-  test "ticket quality _ after concert" do
+  test "passes quality _ after concert" do
     days_left = 0
     initial_quality = 0
-    [_, ticket, _, _, _] = create_items(days_left, initial_quality) |> elapse_days(1)
+    [_, passes, _, _, _] = create_items(days_left, initial_quality) |> elapse_days(1)
 
-    assert ticket === %Item{name: @passes, sell_in: -1, quality: 0}
+    assert passes === %Item{name: @passes, sell_in: -1, quality: 0}
   end
+  
+  # Brie
 
   test "brie quality _ greater than 0 days left " do
     days_left = 1
@@ -136,7 +145,6 @@ defmodule GildedRoseTest do
     assert brie === %Item{name: @brie, sell_in: 0, quality: 1}
   end
 
-
   test "brie quality _ past sell in day" do
     days_left = 0
     initial_quality = 0
@@ -145,6 +153,8 @@ defmodule GildedRoseTest do
     assert brie === %Item{name: @brie, sell_in: -1, quality: 2}
   end
 
+  # Sulfuras
+
   test "sulfuras quality _ any days left" do
     days_left = 20
     initial_quality = 40
@@ -161,6 +171,8 @@ defmodule GildedRoseTest do
     assert sulfuras === %Item{name: @sulfuras, sell_in: 20, quality: 80}
   end
 
+  # Max quality
+
   test "all items quality _ reaching max quality" do
     days_left = 5
     initial_quality = 49
@@ -174,6 +186,4 @@ defmodule GildedRoseTest do
       %Item{name: @conjured, sell_in: 0, quality: 39},
     ]
   end
-
-
 end