nodejs for play assets

gistfile1.scala

object Compiler4CoffeeScript {

    import play.core.coffeescript._
    import org.mozilla.javascript.JavaScriptException
    import play.core.coffeescript.CompilationException

    def compile(files: Array[File]): String =
        (files.map{
            f =>
                try {
                    NodeJs.call(Seq("coffee", "--print", "--bare", f.getAbsolutePath))
                } catch {
                    case e: JavaScriptException =>
                        throw CompilationException(e.getValue.toString, f, None)
                }
        }).mkString("\n")
}

object NodeJs {

    import scala.sys.process._
    import org.mozilla.javascript._

    def call(cmd: Seq[String]) = {
        // I/O
        val stderr = new StringBuffer()
        val stdout = new StringBuffer()
        val logger = ProcessLogger(
            (out: String) => {
                stdout append (out + "\n")
            },
            (err: String) => {
                stdout append (err + "\n")
            })

        // exec
        val process = Process(cmd.mkString(" "))
        val exit = process ! logger
        val out = stdout.toString

        if (exit != 0)
            throw new JavaScriptException(out)
        out
    }
}