1 files changed, 72 insertions, 0 deletions
diff --git a/scalajslib/src/ScalaJSWorkerApi.scala b/scalajslib/src/ScalaJSWorkerApi.scala
new file mode 100644
index 00000000..bcaeb2d3
--- /dev/null
+++ b/scalajslib/src/ScalaJSWorkerApi.scala
@@ -0,0 +1,72 @@
+package mill.scalajslib
+
+import java.io.File
+import java.net.URLClassLoader
+
+import mill.define.Discover
+import mill.api.Result
+import mill.api.Ctx
+import mill.{Agg, T}
+import mill.scalajslib.api._
+class ScalaJSWorker {
+  private var scalaInstanceCache = Option.empty[(Long, ScalaJSWorkerApi)]
+
+  private def bridge(toolsClasspath: Agg[os.Path])
+                    (implicit ctx: Ctx.Home) = {
+    val classloaderSig =
+      toolsClasspath.map(p => p.toString().hashCode + os.mtime(p)).sum
+    scalaInstanceCache match {
+      case Some((sig, bridge)) if sig == classloaderSig => bridge
+      case _ =>
+        val cl = mill.api.ClassLoader.create(
+          toolsClasspath.map(_.toIO.toURI.toURL).toVector,
+          getClass.getClassLoader
+        )
+        val bridge = cl
+          .loadClass("mill.scalajslib.worker.ScalaJSWorkerImpl")
+          .getDeclaredConstructor()
+          .newInstance()
+          .asInstanceOf[ScalaJSWorkerApi]
+        scalaInstanceCache = Some((classloaderSig, bridge))
+        bridge
+    }
+  }
+
+  def link(toolsClasspath: Agg[os.Path],
+           sources: Agg[os.Path],
+           libraries: Agg[os.Path],
+           dest: File,
+           main: Option[String],
+           fullOpt: Boolean,
+           moduleKind: ModuleKind)
+          (implicit ctx: Ctx.Home): Result[os.Path] = {
+    bridge(toolsClasspath).link(
+      sources.items.map(_.toIO).toArray,
+      libraries.items.map(_.toIO).toArray,
+      dest,
+      main.orNull,
+      fullOpt,
+      moduleKind
+    ).map(os.Path(_))
+  }
+
+  def run(toolsClasspath: Agg[os.Path], config: NodeJSConfig, linkedFile: File)
+         (implicit ctx: Ctx.Home): Unit = {
+    bridge(toolsClasspath).run(config, linkedFile)
+  }
+
+  def getFramework(toolsClasspath: Agg[os.Path],
+                   config: NodeJSConfig,
+                   frameworkName: String,
+                   linkedFile: File)
+                  (implicit ctx: Ctx.Home): (() => Unit, sbt.testing.Framework) = {
+    bridge(toolsClasspath).getFramework(config, frameworkName, linkedFile)
+  }
+
+}
+
+object ScalaJSWorkerApi extends mill.define.ExternalModule {
+
+  def scalaJSWorker = T.worker { new ScalaJSWorker() }
+  lazy val millDiscover = Discover[this.type]
+}