How to execute a bash script as sbt task?

Question

I want to automatically build documentation for my Java Play 2.3 application. At the moment, I use a Makefile to generate images from *.dotfiles and combine Mar

Answer 1

You can find some answers in External Processes in the official documentation of sbt, e.g.

To run an external command, follow it with an exclamation mark !:

 "find project -name *.jar" !

Don't forget to use import scala.sys.process._ so ! can be resolved as a method of String.

Do the following in activator console (aka sbt shell) to execute yourshell.sh - mind the eval command and the quotes around the name of the script:

eval "yourshell.sh" !

To have it available as a task add the following to build.sbt of your project:

lazy val execScript = taskKey[Unit]("Execute the shell script")

execScript := {
  "yourshell.sh" !
}

Answer 2

We had the requirement to execute some npm scripts as sbt task and let the build fail if one of the npm scripts fails. Took me some time to find a way to create a Task that works on Windows and Unix. And so here is what I came up with.

lazy val buildFrontend = taskKey[Unit]("Execute frontend scripts")

buildFrontend := {
      val s: TaskStreams = streams.value
      val shell: Seq[String] = if (sys.props("os.name").contains("Windows")) Seq("cmd", "/c") else Seq("bash", "-c")
      val npmInstall: Seq[String] = shell :+ "npm install"
      val npmTest: Seq[String] = shell :+    "npm run test"
      val npmLint: Seq[String] = shell :+    "npm run lint"
      val npmBuild: Seq[String] = shell :+   "npm run build"
      s.log.info("building frontend...")
      if((npmInstall #&& npmTest #&& npmLint #&& npmBuild !) == 0) {
        s.log.success("frontend build successful!")
      } else {
        throw new IllegalStateException("frontend build failed!")
      }
},
(run in Compile) <<= (run in Compile).dependsOn(buildFrontend)