Short example of humanizing clojure.spec/explain-data output

spec-errors-example.cljs

(ns my-app.errors
  (:require [my-app.spec :as spec]
            [cljs.spec.alpha :as s]))

(def error-map
  {::spec/required "This field is required"
   ::spec/max-length "This field is too long"
   :email/regex "Invalid email address"
   :password/regex "Password must contain at least 1 letter and 1 number"
   :password/min-length "Password must be at least 8 characters in length"
   :password/confirm "You must confirm your password"
   :password/equality "Passwords do not match"
   })

(defn- primary-error-spec
  [exp-data]
  (when exp-data
    (-> (get-in exp-data [::s/problems])
        first
        :via
        last)))

(defn- humanize-explain-data
  [exp-data]
  (-> exp-data
      primary-error-spec
      error-map))

(defn error-msg
  "Error message component that humanizes the given s/explain-data output and renders to a span."
  [{:keys [exp-data]}]
  [:span.error (humanize-explain-data exp-data)])