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@mjansen401
Created September 26, 2012 02:03
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GildedRose Clojure solution (with @patrickgombert)
;the code
(ns gilded-rose.core)
(def vest "+5 Dexterity Vest")
(def brie "Aged Brie")
(def elixir "Elixir of the Mongoose")
(def sulfuras "Sulfuras, Hand of Ragnaros")
(def passes "Backstage passes to a TAFKAL80ETC concert")
(def cake "Conjured Mana Cake")
(defn expired? [item]
(< (:sell-in item) 0))
(defn- update-item-attribute [item key value]
(merge item {key value}))
(defn- update-sell-in [item]
(update-item-attribute item :sell-in (dec (:sell-in item))))
(defn- item-name [item] (:name item))
(defn- do-for-updated-sell-in [age-fn item]
(let [item (update-sell-in item)]
(age-fn item)))
(defmulti age-item item-name)
(defmethod age-item cake [item]
(do-for-updated-sell-in
(fn [item]
(if (<= (:quality item) 0)
item
(update-item-attribute item :quality (- (:quality item) 2))))
item))
(defmethod age-item brie [item]
(do-for-updated-sell-in
(fn [item]
(if (>= (:quality item) 50)
item
(update-item-attribute item :quality (inc (:quality item)))))
item))
(defn- normal-quality-item [item]
(do-for-updated-sell-in
(fn [item]
(cond
(= 0 (:quality item))
item
(expired? item)
(update-item-attribute item :quality (- (:quality item) 2))
:else
(update-item-attribute item :quality (dec (:quality item)))))
item))
(defmethod age-item vest [item]
(normal-quality-item item))
(defmethod age-item elixir [item]
(normal-quality-item item))
(defn in-range-inclusive [start end value]
(and (>= value start) (< value end)))
(defmethod age-item passes [item]
(do-for-updated-sell-in
(fn [item]
(let [sell-in (:sell-in item)
quality (:quality item)]
(cond
(expired? item)
(update-item-attribute item :quality 0)
(in-range-inclusive 0 5 sell-in)
(update-item-attribute item :quality (+ 3 quality))
(in-range-inclusive 5 10 sell-in)
(update-item-attribute item :quality (+ 2 quality))
:else
(update-item-attribute item :quality (+ 1 quality)))))
item))
(defmethod age-item :default [item]
item)
(defn update-quality [items]
(map age-item items))
;the specs
(ns gilded-rose.core-spec
(:require [speclj.core :refer :all]
[gilded-rose.core :refer [update-quality update-sell-in update-item-quality expired? normal-quality?]]))
(def vest "+5 Dexterity Vest")
(def brie "Aged Brie")
(def elixir "Elixir of the Mongoose")
(def sulfuras "Sulfuras, Hand of Ragnaros")
(def passes "Backstage passes to a TAFKAL80ETC concert")
(def cake "Conjured Mana Cake")
(def inventory
[
{:name vest :sell-in 10 :quality 20}
{:name brie :sell-in 2 :quality 0}
{:name elixir :sell-in 5 :quality 7}
{:name sulfuras :sell-in 0 :quality 80}
{:name passes :sell-in 15 :quality 20}
{:name cake :sell-in 3 :quality 6}
])
(defn update-quality-n-times [i, n]
(loop [items i count 0]
(if (= count n)
items
(recur (update-quality items) (inc count)))))
(defn item-by-name [item-name items]
(first (filter (fn[item] (= item-name (:name item))) items)))
(defn updated-sell-in [item-name updated-items]
(:sell-in (item-by-name item-name updated-items)))
(defn updated-quality [item-name updated-items]
(:quality (item-by-name item-name updated-items)))
(describe "gilded rose"
(describe "acceptance tests"
(describe "sell_in values"
(it "decreases by 1 after one update for non-legendary items"
(let [[updated-items] [(update-quality-n-times inventory 1)]]
(should= 9 (updated-sell-in vest updated-items))
(should= 1 (updated-sell-in brie updated-items))
(should= 4 (updated-sell-in elixir updated-items))
(should= 14 (updated-sell-in passes updated-items))
))
(it "decreases by 2 after two updates for non-legendary items"
(let [[updated-items] [(update-quality (update-quality-n-times inventory 1))]]
(should= 8 (updated-sell-in vest updated-items))
(should= 0 (updated-sell-in brie updated-items))
(should= 3 (updated-sell-in elixir updated-items))
(should= 13 (updated-sell-in passes updated-items))
))
(it "stays constant for legendary items"
(let [[items-updated-once] [(update-quality-n-times inventory 1)]]
(should= 0 (updated-sell-in sulfuras items-updated-once))
(should= 0 (updated-sell-in sulfuras (update-quality items-updated-once)))
))
)
(describe "quality values"
(describe "normal items"
(it "decreases the quality by 1"
(should= 19 (updated-quality vest (update-quality-n-times inventory 1)))
(should= 6 (updated-quality elixir (update-quality-n-times inventory 1))))
(it "decreases the quality by 2 when item expired"
(should= 8 (updated-quality vest (update-quality-n-times inventory 11)))
(should= 0 (updated-quality elixir (update-quality-n-times inventory 6))))
)
(describe "aged brie"
(it "increases in quality as it ages"
(should= 1 (updated-quality brie (update-quality-n-times inventory 1))))
(it "never gets above 50 quality"
(should= 50 (updated-quality brie (update-quality-n-times inventory 55))))
)
(describe "sulfuras"
(it "never decreases in quality"
(should= 80 (updated-quality sulfuras (update-quality-n-times inventory 10))))
)
(describe "passes"
(it "increases in quality by 1 with more than 10 days to sell"
(should= 25 (updated-quality passes (update-quality-n-times inventory 5))))
(it "increases in quality by 2 with more than 5 days and less than 10 to sell"
(should= 35 (updated-quality passes (update-quality-n-times inventory 10))))
(it "increases in quality by 3 with more than 0 days and less than 5 to sell"
(should= 50 (updated-quality passes (update-quality-n-times inventory 15))))
(it "drops to 0 when expired"
(should= 0 (updated-quality passes (update-quality-n-times inventory 16))))
)
)
)
)
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