1 files changed, 88 insertions, 0 deletions
diff --git a/src/main/scala/workbench/WorkbenchSplicePlugin.scala b/src/main/scala/workbench/WorkbenchSplicePlugin.scala
new file mode 100644
index 0000000..9d68ad3
--- /dev/null
+++ b/src/main/scala/workbench/WorkbenchSplicePlugin.scala
@@ -0,0 +1,88 @@
+package com.lihaoyi.workbench
+import scala.concurrent.ExecutionContext.Implicits.global
+import sbt._
+import sbt.Keys._
+import autowire._
+import org.scalajs.sbtplugin.ScalaJSPlugin
+import org.scalajs.core.tools.io._
+import org.scalajs.sbtplugin.ScalaJSPluginInternal._
+import org.scalajs.sbtplugin.Implicits._
+
+object WorkbenchSplicePlugin extends AutoPlugin {
+
+  override def requires = WorkbenchPlugin
+
+  object autoImport {
+    val updatedJS = taskKey[List[String]]("Provides the addresses of the JS files that have changed")
+    val spliceBrowsers = taskKey[Unit]("Attempts to do a live update of the code running in the browser while maintaining state")
+  }
+  import autoImport._
+  import WorkbenchBasePlugin.autoImport._
+  import WorkbenchBasePlugin.server
+  import ScalaJSPlugin.AutoImport._
+
+  val spliceSettings = Seq(
+    updatedJS := {
+      var files: List[String] = Nil
+      ((crossTarget in Compile).value * "*.js").get.foreach {
+        (x: File) =>
+          streams.value.log.info("workbench: Checking " + x.getName)
+          FileFunction.cached(streams.value.cacheDirectory / x.getName, FilesInfo.lastModified, FilesInfo.lastModified) {
+            (f: Set[File]) =>
+              val fsPath = f.head.getAbsolutePath.drop(new File("").getAbsolutePath.length)
+              files = fsPath :: files
+              f
+          }(Set(x))
+      }
+      files
+    },
+    updatedJS := {
+      val paths = updatedJS.value
+      val url = localUrl.value
+      paths.map { path =>
+        s"http://${url._1}:${url._2}$path"
+      }
+    },
+    spliceBrowsers := {
+      val changed = updatedJS.value
+      // There is no point in clearing the browser if no js files have changed.
+      if (changed.length > 0) {
+        for{
+          path <- changed
+          if !path.endsWith(".js.js")
+        }{
+          streams.value.log.info("workbench: Splicing " + path)
+          val url = localUrl.value
+          val prefix = s"http://${url._1}:${url._2}/"
+          val s = munge(sbt.IO.read(new sbt.File(path.drop(prefix.length))))
+
+          sbt.IO.write(new sbt.File(path.drop(prefix.length) + ".js"), s.getBytes)
+          server.value.Wire[Api].run(path + ".js").call()
+        }
+      }
+    },
+    spliceBrowsers <<= spliceBrowsers.triggeredBy(fastOptJS in Compile)
+  )
+    
+  override def projectSettings = spliceSettings
+
+  def munge(s0: String) = {
+    var s = s0
+    s = s.replace("\nvar ScalaJS = ", "\nvar ScalaJS = ScalaJS || ")
+    s = s.replaceAll(
+      "\n(ScalaJS\\.c\\.[a-zA-Z_$0-9]+\\.prototype) = (.*?\n)",
+      """
+        |$1 = $1 || {}
+        |(function(){
+        |  var newProto = $2
+        |  for (var attrname in newProto) { $1[attrname] = newProto[attrname]; }
+        |})()
+        |""".stripMargin
+    )
+    for(char <- Seq("d", "c", "h", "i", "n", "m")){
+      s = s.replaceAll("\n(ScalaJS\\." + char + "\\.[a-zA-Z_$0-9]+) = ", "\n$1 = $1 || ")
+    }
+    s
+  }
+
+}