sbt how to get result (success/failed) of compile in an sbt task

Question

I am trying to write an sbt task that checks if the code compilation succeeds or fails and based on that information, does something. So far I have this:

https://github.com/JohnReedLOL/WeirdSbtBug/blob/894f497567477619b4150de92c6bb2c146a1b615/build.sbt#L46

When compilation failed, it printed out this:

[warn] Compile: Inc(Incomplete(node=Some(Task((taskDefinitionKey: ScopedKey(Scope(Select(ProjectRef(file:/Users/john-michaelreed/Downloads/NewDownloads/sbt-0.13/lesson/HelloScala1/,helloscala1)),Select(ConfigKey(compile)),Global,Global),compile)))), tpe=Error, msg=None, causes=List(Incomplete(node=Some(Task((tags: Map(Tag(compile) -> 1, Tag(cpu) -> 1), taskDefinitionKey: ScopedKey(Scope(Select(ProjectRef(file:/Users/john-michaelreed/Downloads/NewDownloads/sbt-0.13/lesson/HelloScala1/,helloscala1)),Select(ConfigKey(compile)),Global,Global),compileIncremental)))), tpe=Error, msg=None, causes=List(), directCause=Some(Compilation failed))), directCause=None)) !

which contains the String "Compilation failed". I could check to see if that String is present and based on the result of that, do something.

Example:

val monitorTask = taskKey[Unit]("A task that gets the result of compile.")
monitorTask in Scope.GlobalScope := {
  // monitorTask dependencies:
  val log = streams.value.log // streams task happens-before monitorTask
  val compileResult = (compile.in(Compile)).result.value // compile task happens-before monitorTask

  // ---- monitorTask begins here ----
  if(compileResult.toString.contains("Compilation failed")) {
    log.warn("Compilation failed!")
    // Do stuff
  } else {
    log.info("Compilation succeeded!")
    // Do other stuff
  }
}

But that looks a little fragile. Is there a better way to do that?

p.s. In the process of testing monitorTask, I ran into this bug: https://github.com/sbt/sbt/issues/4444

Answer 1

If you want binary success or fail information why not call toEither on .result.value? You can then check if it's isRight.