experimenting with quickcheck style tests

src/circumspec/for_all.clj

@@ -0,0 +1,51 @@
+(ns circumspec.for-all
+  (:use [clojure.contrib.seq-utils :only (rand-elt)]))
+
+(def *size* 100)
+
+(defmacro defgenerator [sym & forms]
+  `(def ~sym ~@forms))
+
+(defn data-name-for-generator-coll
+  [generator-sym]
+  (symbol (str generator-sym "*")))
+
+(defmacro generator-coll
+  [sym coll]
+  (let [data-name (data-name-for-generator-coll sym)]
+    `(do
+       (def ~data-name ~coll)
+       (defn ~sym [] (rand-elt ~data-name)))))
+
+(defn choose-from
+  [& generators]
+  (fn [] ((rand-elt generators))))
+
+(defn list-of
+  [& generators]
+  (let [gen (apply choose-from generators)]
+    (fn [] (take (rand-int *size*) (repeatedly gen)))))
+
+(defn string-of
+  [& generators]
+  (let [gen (apply list-of generators)]
+    (fn [] (apply str (gen)))))
+
+(defn symbol-of
+  [& generators]
+  (let [gen (apply string-of generators)]
+    (fn [] (symbol (gen)))))
+
+(generator-coll famous-string [nil ""])
+(generator-coll famous-whitespace " \t\n")
+(generator-coll digits "1234567890")
+(generator-coll ascii-upper "ABCDEFGHIJKLMNOPQRSTUVWXYZ")
+(generator-coll ascii-lower "abcdefghijklmnopqrstuvwxyz")
+(defgenerator ascii-alpha (choose-from ascii-upper ascii-lower))
+
+(defmacro for-all
+  [bindings & body]
+  `(dotimes [_# *size*]
+     (let ~bindings
+       ~@body)))
+

test/circumspec/utils_test.clj

@@ -1,7 +1,18 @@
 (ns circumspec.utils-test
-  (:use circumspec circumspec.utils
+  (:use circumspec circumspec.utils circumspec.for-all
         clojure.contrib.with-ns))
 
+(testing dasherize
+  (let [whitespacey-string (string-of ascii-alpha famous-whitespace)]
+    (for-all [s (whitespacey-string)]
+             (should (not (re-find #" |\t|\n" (dasherize s)))))))
+
+(testing "class-symbol always returns a boolean"
+  (let [ascii-symbol (symbol-of ascii-alpha)]
+    (for-all [s (ascii-symbol)]
+             (when-not (= s (symbol "")) ;; clojure bug? empty symbol barfs
+               (should (contains? #{true false} (class-symbol? s)))))))
+
 (testing pop-optional-args
   (for-these [output input] (should (= output (apply pop-optional-args input)))
              [[1 2]] [[] [1 2]]