todo-spec-issue.cljs

(ns todo-spec-issue
  (:require
        [clojure.spec :as s]
        [clojure.spec.test :as stest]
        [clojure.spec.impl.gen :as gen]))

(s/def ::id int?)
(s/def ::name string?)
(s/def ::todo (s/keys :req-un [::id ::name]))
(s/def ::todos (s/and
                    (s/map-of ::id ::todo)
                    #(sorted? %)
                    ))
(s/def ::db (s/keys :req-un [::todos]))

(println "First sample:")
(println (gen/sample (s/gen ::db) 1))
;or
(println "First exercise:")
(println (s/exercise ::db 1))
;gives:

;Uncaught cljs.core.ExceptionInfo
;message: "Couldn't satisfy such-that predicate after 100 tries."


;Whereas:
(s/def ::todos (s/and
                    (s/map-of ::id ::todo)
                    ))
(s/def ::db (s/keys :req-un [::todos]))

(println "Second sample:")
(println (gen/sample (s/gen ::db) 1))
;gives:
;({:todos {0 {:id 0, :name ""}, -1 {:id -1, :name ""}}})

;and
(println "Second exercise:")
(s/exercise ::db 1)
;gives:
;([{:todos {-1 {:id -1, :name ""}, 0 {:id 0, :name ""}}}
;  {:todos {-1 {:id -1, :name ""}, 0 {:id 0, :name ""}}}])