spec-clojure-core.clj

(require '[clojure.spec :as s])

(defmacro tpe [  & forms ]
  `(try
     ~@forms
     (catch Exception e#
       (println "Form:            " (pr-str '~@forms))
       (println "Exception Class: " (.getClass e#))
       (println "Message:         " (.getMessage e#))
       (println))))

(defn header [s]
  (println "=========================================================")
  (println s)
  (println "========================================================="))

(s/fdef clojure.core/map
        :args (s/cat :fn ifn?
                     :seq (s/* sequential?))
        :return sequential?)

(header "Before instrumenting clojure.core/map")

(tpe (into [] (map nil [1 2 3] [1 2 3])))

(tpe (into [] (map 1 [1 2 3] [1 2 3])))

(tpe (into [] (map identity 4)))

(header "After instrumenting clojure.core/map")
(s/instrument #'clojure.core/map)

(tpe (into [] (map nil [1 2 3] [1 2 3])))

(tpe (into [] (map 1 [1 2 3] [1 2 3])))

(tpe (into [] (map identity 4)))

(header "Before instrumenting clojure.core/identity")
(tpe (into [] (map identity [1 2 3] [1 2 3])))

(s/fdef clojure.core/identity
        :args (s/cat :one-argument (constantly true)))

(s/instrument #'clojure.core/identity)

(header "After instrumenting clojure.core/identity")
(tpe (into [] (map identity [1 2 3] [4 5 6])))

% java -jar ~/.m2/repository/org/clojure/clojure/1.9.0-alpha5/clojure-1.9.0-alpha5.jar core.clj
=========================================================
Before instrumenting clojure.core/map
=========================================================
Form:             (into [] (map nil [1 2 3] [1 2 3]))
Exception Class:  java.lang.NullPointerException
Message:          nil

Form:             (into [] (map 1 [1 2 3] [1 2 3]))
Exception Class:  java.lang.ClassCastException
Message:          java.lang.Long cannot be cast to clojure.lang.IFn

Form:             (into [] (map identity 4))
Exception Class:  java.lang.IllegalArgumentException
Message:          Don't know how to create ISeq from: java.lang.Long

=========================================================
After instrumenting clojure.core/map
=========================================================
Form:             (into [] (map nil [1 2 3] [1 2 3]))
Exception Class:  clojure.lang.ExceptionInfo
Message:          Call to #'clojure.core/map did not conform to spec:
In: [0] val: nil fails at: [:args :fn] predicate: ifn?
:clojure.spec/args  (nil [1 2 3] [1 2 3])


Form:             (into [] (map 1 [1 2 3] [1 2 3]))
Exception Class:  clojure.lang.ExceptionInfo
Message:          Call to #'clojure.core/map did not conform to spec:
In: [0] val: 1 fails at: [:args :fn] predicate: ifn?
:clojure.spec/args  (1 [1 2 3] [1 2 3])


Form:             (into [] (map identity 4))
Exception Class:  clojure.lang.ExceptionInfo
Message:          Call to #'clojure.core/map did not conform to spec:
In: [1] val: 4 fails at: [:args :seq] predicate: sequential?
:clojure.spec/args  (#object[clojure.core$identity 0x15a04efb "clojure.core$identity@15a04efb"] 4)


=========================================================
Before instrumenting clojure.core/identity
=========================================================
Form:             (into [] (map identity [1 2 3] [1 2 3]))
Exception Class:  clojure.lang.ArityException
Message:          Wrong number of args (2) passed to: core/identity

=========================================================
After instrumenting clojure.core/identity
=========================================================
Form:             (into [] (map identity [1 2 3] [4 5 6]))
Exception Class:  clojure.lang.ExceptionInfo
Message:          Call to #'clojure.core/identity did not conform to spec:
In: [1] val: (4) fails at: [:args] predicate: (cat :one-argument identity),  Extra input
:clojure.spec/args  (1 4)