spec.clj

(s/def ::a integer?)
(s/def ::b string?)

(clojure.pprint/pprint (s/explain-data (s/keys :req [::a ::b]) {::a "foo" ::b "bar"}))

;; =>                                                                                                                                                       
;; {:clojure.spec/problems                                                                                                                                  
;;  {[:empathy.api/a]                                                                                                                                       
;;   {:pred integer?,                                                                                                                                       
;;    :val "foo",                                                                                                                                           
;;    :via [:empathy.api/a],                                                                                                                                
;;    :in [:empathy.api/a]}}}  

(clojure.pprint/pprint (s/explain-data (s/keys :req [::a ::b]) {}))

;; =>                                                                                                                                                       
;; {:clojure.spec/problems                                                                                                                                  
;;  {[]                                                                                                                                                     
;;   {:pred [(contains? % :empathy.api/a) (contains? % :empathy.api/b)],                                                                                    
;;    :val {},                                                                                                                                              
;;    :via [],                                                                                                                                              
;;    :in []}}}                                                                                                                                             


(clojure.pprint/pprint (s/explain-data (s/tuple ::a) []))

;; =>                                                                                                                                                       
;; {:clojure.spec/problems                                                                                                                                  
;;  {[]                                                                                                                                                     
;;   {:pred (clojure.core/= (clojure.core/count %) 1),                                                                                                      
;;    :val [],                                                                                                                                              
;;    :via [],                                                                                                                                              
;;    :in []}}}