Move hashing css file step from shadow-cljs hook to build (#3)

Author: abogoyavlensky

build.clj

@@ -1,5 +1,10 @@
 (ns build
-  (:require [clojure.tools.build.api :as b]))
+  (:require [clojure.tools.build.api :as b]
+            [clojure.java.io :as io]
+            [clojure.string :as str])
+  (:import [java.security MessageDigest]
+           [java.math BigInteger]
+           [java.nio.file Paths]))
 
 (def ^:private TARGET-DIR "target")
 (def ^:private CLASS-DIR (format "%s/classes" TARGET-DIR))
@@ -25,10 +30,48 @@
            :basis @basis
            :main main-ns}))
 
+(defn- md5
+  [^String s]
+  (->> (.getBytes s)
+       (.digest (MessageDigest/getInstance "MD5"))
+       (BigInteger. 1)
+       (format "%032x")))
+
+
+(defn- join-path
+  [p & ps]
+  (str (.normalize (Paths/get p (into-array String ps)))))
+
+
+(defn- file-name-with-hash
+  [content-hash file-name-in-html]
+  (let [file-name-split (str/split file-name-in-html #"\.")
+        new-file-name-split (-> file-name-split
+                                (butlast)
+                                (concat [content-hash (last file-name-split)]))]
+    (str/join "." new-file-name-split)))
+
+
+(defn- hash-css
+  "Rename css file in html with hash of the file."
+  [{:keys [output-file-path file-name-in-html html-file-path]
+    :or {html-file-path "resources/public/index.html"}}]
+  (let [output-file (io/file output-file-path)
+        new-file-name (-> (slurp output-file)
+                          (md5)
+                          (file-name-with-hash file-name-in-html))
+        new-file-path (join-path (.getParent output-file) new-file-name)
+        html (slurp html-file-path)]
+    (.renameTo output-file (io/file new-file-path))
+    (->> (str/replace html file-name-in-html new-file-name)
+         (spit html-file-path))))
+
 (defn build
   "Build an uberjar."
   [_]
   (clean)
+  (hash-css {:output-file-path "resources/public/css/output-prod.css"
+             :file-name-in-html "output.css"})
   (uber {:uber-file UBER-FILE
          :class-dir CLASS-DIR
          :main-ns MAIN-NS}))

shadow-cljs.edn

@@ -7,11 +7,7 @@
                 :devtools {:watch-dir "resources/public"
                            :watch-path "/assets"
                            :after-load ui.main/render!}
-                :release {:build-hooks [; Update file name in index.html with hash
-                                        (api.util.build/hash-css
-                                          {:output-file-path "resources/public/css/output-prod.css"
-                                           :file-name-in-html "output.css"})
-                                        ; Update js file name in index.html with hash
+                :release {:build-hooks [; Update js file name in index.html with hash
                                         (shadow.html/copy-file
                                           "resources/public/index.html"
                                           "resources/public/index.html")]}}}}