Run command in Tauri Scala.js

tauri-scalajs-command.scala

import tauri.ShellMod
import typings.std.stdStrings.close
import typings.tauriAppsApi.tauriAppsApiStrings
import scala.util.Failure
import scala.util.Success
import scala.concurrent.Future
import scala.collection.mutable.ArrayBuffer
import scala.concurrent.Promise
import scalajs.js.JSConverters.iterableOnceConvertible2JSRichIterableOnce


def lineAsString(line: Any): String = {
  if (line.isInstanceOf[String]) {
    return line.asInstanceOf[String]
  }
  throw Exception("Bad line type")
}


def runCommand(cmd: String, args: List[String]): Future[String] = {
    val command = ShellMod.Command(cmd, args.toJSArray)

    val lines = ArrayBuffer[String]()
    val errLines = ArrayBuffer[String]()

    val completionPromise = Promise[String]
    command.on(tauriAppsApiStrings.close, data => {
      val code = data.asInstanceOf[js.Dynamic].selectDynamic("code").asInstanceOf[Int]
      if (code == 0) {
        completionPromise.success(lines.mkString("\n"))
      } else {
        completionPromise.failure(new Exception(errLines.mkString("\n")))
      }
      println(s"command finished with code ${code}")
    })

    command.stdout.on(tauriAppsApiStrings.data, line => {
      println("line: " + line)
      lines += lineAsString(line)
    })
    command.stderr.on(tauriAppsApiStrings.data, line => {
      println("line: " + line)
      errLines += lineAsString(line)
    })
    command.spawn().toFuture.onComplete(tr => {
      tr match
        case Failure(exception) => 
          completionPromise.failure(exception)
        case Success(value) =>
          // child pid not needed
    })
    completionPromise.future
}