boo.clj

(defn allowed-keys?
  [ks]
  #(set/superset? ks (set (clojure.core/keys %))))

(defmacro keys
  "Like clojure.spec.alpha/keys but allow to pass a `:closed?` parameter
  to make the spec strict on allowed keys."
  [& {:keys [closed? req req-un opt opt-un _gen] :as args}]
  (let [keys-form `(s/keys ~@(apply concat args))]
    (if closed?
      `(-> (s/and map?
                  (allowed-keys? ~(into #{}
                                        (filter keyword?)
                                        (concat [opt opt-un]
                                                ;; support or/and
                                                (flatten [req req-un]))))
                  ~keys-form)
           (s/with-gen #(s/gen ~keys-form)))
      keys-form)))