vmunier · WayneWang12 · Feb 8, 2022
diff --git a/src/main/g8/build.sbt b/src/main/g8/build.sbt
@@ -17,7 +17,7 @@ lazy val server = project
       "com.vmunier" %% "scalajs-scripts" % "1.2.0"
     ),
     Assets / WebKeys.packagePrefix := "public/",
-    Runtime / managedClasspath += (Assets / packageBin).value
+    Runtime / unmanagedClasspath += (Assets / packageBin).value
   )
   .enablePlugins(SbtWeb, SbtTwirl, JavaAppPackaging)
   .dependsOn(shared.jvm)

diff --git a/src/main/g8/server/src/main/scala/$package$/VersionedResourceFinder.scala b/src/main/g8/server/src/main/scala/$package$/VersionedResourceFinder.scala
@@ -0,0 +1,63 @@
+import java.net.URL
+import scala.collection.concurrent.TrieMap
+import scala.concurrent.blocking
+
+/**
+ * Copy from play framework.
+ */
+object VersionedResourceFinder {
+  // Sames goes for the minified paths cache.
+  private lazy val minifiedPathsCache = TrieMap[String, String]()
+
+  private def resource(str: String): Option[URL] = Option(
+    getClass.getClassLoader.getResource(str)
+  )
+
+  private def minifiedPath(path: String): String = {
+    minifiedPathsCache.getOrElse(
+      path, {
+        def minifiedPathFor(delim: Char): Option[String] = {
+          val ext = path.reverse.takeWhile(_ != '.').reverse
+          val noextPath = path.dropRight(ext.length + 1)
+          val minPath = noextPath + delim + "min." + ext
+          Option(getClass.getResource(minPath)).map(_ => minPath)
+        }
+
+        val maybeMinifiedPath =
+          minifiedPathFor('.').orElse(minifiedPathFor('-')).getOrElse(path)
+        minifiedPathsCache.put(path, maybeMinifiedPath)
+        maybeMinifiedPath
+      }
+    )
+  }
+
+  private lazy val digestCache = TrieMap[String, Option[String]]()
+
+  lazy val digestAlgorithm: String = "md5"
+
+  private def digest(path: String): Option[String] = {
+    digestCache.getOrElse(
+      path, {
+        val maybeDigestUrl: Option[URL] =
+          resource(path + "." + digestAlgorithm)
+        val maybeDigest: Option[String] = maybeDigestUrl.map { url =>
+          val source = scala.io.Source.fromURL(url)
+          try source.getLines.mkString.trim
+          finally source.close()
+        }
+        if (maybeDigest.isDefined) digestCache.put(path, maybeDigest)
+        maybeDigest
+      }
+    )
+  }
+
+  def findAssetPath(base: String, path: String): String = blocking {
+    val minPath = minifiedPath(path)
+    digest(minPath)
+      .fold(minPath) { dgst =>
+        val lastSep = minPath.lastIndexOf("/")
+        minPath.take(lastSep + 1) + dgst + "-" + minPath.drop(lastSep + 1)
+      }
+      .drop(base.length + 1)
+  }
+}
diff --git a/src/main/g8/server/src/main/twirl/$package$/main.scala.html b/src/main/g8/server/src/main/twirl/$package$/main.scala.html
@@ -8,6 +8,10 @@
   </head>
   <body>
     @content
-    @scalajs.html.scripts("client", name => s"/assets/$name", name => getClass.getResource(s"/public/$name") != null)
+    @scalajs.html.scripts("client",
+      name => {
+        val versionedJs = VersionedResourceFinder.findAssetPath("public", s"public/$name")
+        s"/assets/$versionedJs"
+    }, name => getClass.getResource(s"/public/$name") != null)
   </body>
 </html>