Clojure Rot13 test

rot13.clj

(ns tst.clj.core
  (:use clj.core
        clojure.test 
        tupelo.core))
      
(def first-char \a)
(def first-char-val (int first-char))

(defn str->codes
  [arg-str]
  (mapv int (vec arg-str)))

(defn codes->str
  [codes-vec]
  (str/join (mapv char codes-vec)))

(defn codes->baseline
  [codes-vec]
  (mapv #(- % first-char-val) codes-vec))

(defn baseline->codes
  [codes-vec]
  (mapv #(+ % first-char-val) codes-vec))

(defn rot13
  [code-vec]
  (mapv (fn [char-code]
          (it-> (+ 13 char-code)
            (mod it 26)))
    code-vec ))

(defn transcode
  [arg-str]
  (it->
    (str->codes arg-str)
    (codes->baseline it)
    (rot13 it)
    (baseline->codes it)
    (codes->str it)))
  
(deftest t1
  (let [x1 (spyx (str->codes "hello"))
        x2 (spyx (codes->baseline x1))
        x3 (spyx (rot13 x2))
        ]
    (is (= [104 101 108 108 111]) x2)
    (is (= [7 4 11 11 14]) x2)
    (is (= [20 17 24 24 1] x3))
    (is (= "uryyb" (transcode "hello")))
    (is (= "hello" (transcode (transcode "hello"))))))