validate-auth updated with cond-let

gistfile1.clj

(defn validate-auth
  "Validates the authentication data and returns vector of [error-message user-data]. On success, the error-message will 
  be nil."
  [db-connection user-id user-password]
  (cond-let
    (str/is-blank? user-id)
    ["user-id not specified"]
      
    (str/is-blank? user-password)
    ["password not specified"]
      
    [user-data (read-user-by-id db-connection user-id)]

    (nil? user-data)
    ["user not found"]
       
    (not (password/is-valid? (:password-hash user-data)) user-password)
    ["password not valid"]
         
    (:is-expired user-data)
    ["user has expired"]
         
    :else
    [nil (dissoc user-data :password-hash)]))