Unexpected clojure.spec behaviour

core.cljs

(namespace foo.core
           (:require [clojure.spec.alpha :as s]))

(s/def ::n (s/or :integer integer? :string string?))

(s/def ::m (s/keys :req-un [::n]))

(defn m-even? [m] (even? (:n m)))

(s/def ::m-even (s/and ::m m-even?))

(s/valid? ::m {:n 2}) ;; => true

(s/valid? m-even? {:n 2}) ;; => true

(s/valid? ::m-even {:n 2}) ;; => false 

(s/explain ::m-even {:n 2}) ;; => #object[Error Error: Argument must be an integer: [object Object]]

;; To resolve this, the predicate m-even? must be applied to the "unformed" conformed value
(def m-even-with-unform? (comp m-even? (partial s/unform ::m)))

(s/def ::m-even-with-unform (s/and ::m m-even-with-unform?)
           
(s/valid? ::m-even-with-unform {:n 2}) ;; => true