repl-ay.clj

(ns net.cgrand.repl-ay)

(defn- prompt? [x] (and (symbol? x) (.endsWith (name x) "=>")))

(def *last-ns-name*)

(defn replay* [forms]
  (loop [forms forms ])
  (when-let [[form & forms] (seq forms)]
    (if (prompt? form) 
      (recur forms)
      (let [r (eval form)]
        (if (and forms (prompt? (first forms)))
          (recur (next forms))
          (let [[expected & forms] forms]
            (when-not (= r expected)
              (println "\nUnexpected value on line" (-> form meta :line) 
                "file" (-> form meta :file))
              (prn '=> form)
              (print "expected: ") (prn expected)
              (print "actual: ") (prn r))
            (recur forms)))))))

(defmacro replay [& forms]
  (let [ns-name (gensym "net.cgrand.repl-ay.session")
        [ns-form forms] (if (and (seq? (first forms)) (= 'ns (ffirst forms)))  
                          [(first forms) (next forms)] ['(ns foo) forms])
        ns-form (list* 'ns ns-name (nnext ns-form))]
    `(binding [*last-ns-name* (ns-name *ns*)]
       (eval '~ns-form) 
       (try
         (replay* '~(vec forms))
         (finally
           (remove-ns '~ns-name)
           (in-ns *last-ns-name*))))))