test.clj

(boot/deftask yaml-to-json
  "Convert YAML file to JSON."
  []
  (let [tmp (boot/tmp-dir!)]
    (comp (boot/with-pre-wrap fileset 
            (doseq [f (->> fileset boot/input-files)]
              (let [in-file  (tmpd/file f)
                    in-path  (tmpd/path f)
                    out-path (change-file-ext in-path "json")
                    out-file (io/file tmp out-path)
                    result   (yaml/parse-string (slurp in-file))]
              (doto out-file
                io/make-parents
                (spit out-path)))
            (-> fileset (boot/add-resource tmp) boot/commit!))
          (tasks/sift :to-source  #{ #"\.yaml$" }))))