Property-based testing dojo

core.clj

(ns dojo.core
  (:require [clojure.test.check :as tc]
            [clojure.test.check.generators :as gen]
            [clojure.test.check.properties :as prop]
            [clojure.test :refer :all]))

(def balls identity)

(defn add-ball [rack ball] (conj rack ball))

(def empty-rack [])

(defmacro defprop [name bindings body]
  `(tc/quick-check 1000 (prop/for-all ~bindings ~body)))

(def gen-ball (gen/choose 0 59))

(defprop "adding to empty rack increases size by one"
  [ball gen-ball]
  (= (count (balls (add-ball empty-rack ball))) 1))

(defprop "adding to empty rack contains the added element"
  [ball gen-ball]
   (= [ball] (balls (add-ball empty-rack ball))))

(def gen-rack (gen/fmap (fn [balls] (reduce add-ball empty-rack (set balls))) (gen/list gen-ball)))

(gen/sample gen-rack)

(defprop "adding-to-rack-contains-one-more-element"
  [rack gen-rack
   ball gen-ball]
  (let [new-rack (add-ball rack ball)]
   (= (count (balls new-rack))
      (inc (count (balls rack))))))

; this is where we finished
; (defprop "adding element give orderd rack"

#_(gen/sample (gen/such-that #(and (= 2 (count %)) (apply not= %))
               (gen/list (gen/elements [:adam :marcin :damian])) 100)
1)

(deftest adding-element-to-empty-rack
  (is (= (balls (add-ball empty-rack 0)) [0])))

project.clj

(defproject dojo "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.7.0"]
                 [org.clojure/test.check "0.8.2"]]
  :main ^:skip-aot dojo.core
  :target-path "target/%s"
  :plugins [[refactor-nrepl "1.1.0"]
          [cider/cider-nrepl "0.9.1"]]
  :profiles {:uberjar {:aot :all}})