clojure.spec being strict on superfluous keys

strict_keys_spec.clj

;; If you want to fail before your old https://github.com/plumatic/schema 
;; function fails the strict-keys macros below will help you find it.

(require '[clojure.spec.alpha :as s]
         '[clojure.set])

(defn allowed-keys? [ks]
  (fn [m]
    (empty? (clojure.set/difference (set (keys m)) ks))))

;; Strict like schema ofs https://github.com/plumatic/schema
(defmacro strict-keys [& {:keys [req-un opt-un req opt] :as config}]
  (let [allowed-keys (set (concat req opt (map (comp keyword name) (concat req-un opt-un))))]
    `(s/and (s/keys ~@(mapcat seq config))
            (allowed-keys? ~allowed-keys))))

(comment

  (s/explain-data (strict-keys :req [:foo/bar]) {:foo/bar 1 :foo/baz 1})
  ;; => {:clojure.spec.alpha/problems [{:path [], :pred (user/allowed-keys? #{:foo/bar}), :val {:foo/bar 1, :foo/baz 1}, :via [], :in []}], :clojure.spec.alpha/spec #object[clojure.spec.alpha$and_spec_impl$reify__47870 0x79dcdd90 "clojure.spec.alpha$and_spec_impl$reify__47870@79dcdd90"], :clojure.spec.alpha/value {:foo/bar 1, :foo/baz 1}}

  )

Probably better to use the strict-keys macro in Bruce Bauman's spell spec library defined over here