Midje `formula`

gistfile1.clj

;; This first swipe at generative-style testing in Midje was super easy:

;; first a use of it

(defn make-string []
  (rand-nth ["a" "b" "c" "d" "e" "f" "g" "i"]))

(formula [a (make-string) b (make-string)]
  (str a b) => #(.startsWith % a))

;; How its defined

(def ^:dynamic *num-generations* 100)

(defmacro formula [bindings & body]
  (macro-for [_ (range *num-generations*)]
    `(let ~bindings
       (midje.sweet/fact
         ~@body))))

;; NOTES: 
;; * just borrow some generator functions from test.generative, and voila 
;;   a stripped down generative test framework.  
;; * this version makes a fact for every generation which would quickly 
;;   make the fact count in the report meaningless.
;; * doc-strings can be added later.

;; QUESTIONS: 
;; * how can we make the reporting of these really nice?
;; * is this it? There has to be more to this kind of thing than simply 
;;   generating 100 of each formula.  What do you think?