refactor/simplify scalaJs plugin and example

- Restructure code as 1 library case class and 1 Build mixin trait. A library is generally easier to understand and could be re-used independently. 1 trait seems simpler than several here.
- Let not the plugin create the multi-project build, but the user project manually. I think while this adds some minor code overhead it is much simpler to understand. Fewer tasks and other moving parts needed.
- Remove verbose nested sbt-style folder structure. It's simpler without it :).

1 files changed, 51 insertions, 0 deletions

diff --git a/plugins/scalajs/ScalaJsLib.scala b/plugins/scalajs/ScalaJsLib.scala
new file mode 100644
index 0000000..0355850
--- /dev/null
+++ b/plugins/scalajs/ScalaJsLib.scala
@@ -0,0 +1,51 @@
+package cbt
+import java.io.File
+
+case class ScalaJsLib(
+  scalaJsVersion: String, scalaVersion: String,
+  cbtHasChanged: Boolean, classLoaderCache: ClassLoaderCache, mavenCache: File
+)(implicit logger: Logger){
+  sealed trait ScalaJsOutputMode {
+    def option: String
+    def fileSuffix: String
+  }
+  case object FastOptJS extends ScalaJsOutputMode{
+    override val option = "--fastOpt"
+    override val fileSuffix = "fastopt"
+  }
+  case object FullOptJS extends ScalaJsOutputMode{
+    override val option = "--fullOpt"
+    override val fileSuffix = "fullopt"
+  }
+
+  val lib = new Lib(logger)
+  def dep(artifactId: String) = MavenResolver( cbtHasChanged, mavenCache, mavenCentral ).bindOne(
+    MavenDependency("org.scala-js", artifactId, scalaJsVersion)
+  )
+
+  def link(
+    mode: ScalaJsOutputMode, outputPath: File,
+    scalaJsOptions: Seq[String], entriesToLink: Seq[File]
+  ) = {
+    val scalaJsCliDep = dep( "scalajs-cli_"++lib.libMajorVersion(scalaVersion) )
+    lib.runMain(
+      "org.scalajs.cli.Scalajsld",
+      Seq(
+        mode.option,
+        "--sourceMap",
+        "--stdlib", s"${scalaJsLibraryDependency.jar.getAbsolutePath}",
+        "--output", outputPath.string
+      ) ++ scalaJsOptions ++ entriesToLink.map(_.getAbsolutePath),
+      scalaJsCliDep.classLoader(classLoaderCache)
+    )
+  }
+
+  val scalaJsLibraryDependency = dep( "scalajs-library_"++lib.libMajorVersion(scalaVersion) )
+
+  // Has to be full Scala version because the compiler is incompatible between versions
+  val scalaJsCompilerDependency = dep( "scalajs-compiler_"++scalaVersion )  
+  val scalacOptions = Seq(
+    "-Xplugin:" ++ scalaJsCompilerDependency.jar.string,
+    "-Xplugin-require:scalajs"
+  )
+}