request.clj

(use 'clojure.test)

(defn same
  "Returns true if (f x) returns same value for any x in coll."
  [f coll]
  (apply = (map f coll)))

(deftest same-test
  (is      (same :x [{:x nil} {:y nil}]))
  (is      (same :x [{:x 1} {:x 1 :y 2}]))
  (is (not (same :x [{:x 1} {:x 2}])))

  (is      (same 0 [[1 2 3] [1 3 2]]))

  (is      (same (comp not nil? #{:x :y}) [:x :y]))
  (is (not (same (comp not nil? #{:x :y}) [:x :y :z])))

  (is      (same (partial identical? 1) [1 1 1 1]))
  (is (not (same (partial identical? 1) [1 1 1 2])))

  (is      (same type [1 2 3]))
  (is (not (same type [1 2 1/2])))

  (is      (same true [true true (= 2 2)]))
  (is (not (same nil? [nil nil false]))))

(same-test)