CODEWITHSUNDEEP
clojureclojure.spec
Steve B.
Steve B.

Reputation: 57333

Having some trouble getting clojure.spec exercise-fn working

In trying to use spec library, I'm getting errors in attempting to use exercise-fn. I've reduced this to the posted example at the main guide page with no change.

relevant code:

(ns spec1
  (:require [clojure.spec.alpha :as s]))

;;this and the fdef are literal copies from the example page
(defn adder [x] #(+ x %))

(s/fdef adder
  :args (s/cat :x number?)
  :ret (s/fspec :args (s/cat :y number?)
                :ret number?)
  :fn #(= (-> % :args :x) ((:ret %) 0)))

Now, typing the following

(s/exercise-fn adder)

gives the error:

Exception No :args spec found, can't generate  clojure.spec.alpha/exercise-fn (alpha.clj:1833)

Dependencies/versions used, [org.clojure/clojure "1.9.0-beta3"] [org.clojure/tools.logging "0.4.0"] [org.clojure/test.check "0.9.0"]

Anyone have any ideas as to why this is breaking? Thanks.

Upvotes: 1

Views: 341

Answers (1)

Alan Thompson
Alan Thompson

Reputation: 29984

You need to backquote the function name, which will add the namespace prefix:

(s/exercise-fn `adder)

For example, in my test code:

(s/fdef ranged-rand
  :args (s/and
          (s/cat :start int? :end int?)
          #(< (:start %) (:end %) 1e9)) ; need add 1e9 limit to avoid integer overflow
  :ret int?
  :fn (s/and #(>= (:ret %) (-> % :args :start))
             #(< (:ret %) (-> % :args :end))))

(dotest
  (when true
    (stest/instrument `ranged-rand)
    (is (thrown? Exception (ranged-rand 8 5))))
  (spyx (s/exercise-fn `ranged-rand)))

Which results in:

(s/exercise-fn (quote tst.tupelo.x.spec/ranged-rand)) 
  => ([(-2 0) -1] [(-4 1) -1] [(-2 0) -2] [(-1 0) -1] [(-14 6) -4] 
      [(-36 51) 45] [(-28 -3) -7] [(0 28) 27] [(-228 -53) -130] [(-2 0) -1])

Note that the namespace-qualified function name tst.tupelo.x.spec/ranged-rand is used.

Upvotes: 5

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