SBT：如何使一个任务依赖于多项目构建中的另一个任务，而不是在根项目中运行？

Question

For my multi-project build, I'm trying to create a verify task that just results in scct:test and then scalastyle being executed in order. I would like scct:test to execute for all the subprojects, but not the top-level project. (If it executes for the top-level project, I get "timed out waiting for coverage report" from scct, since there's no source and no tests in that project.) What I had thought to do was to create verify as a task with dependencies on scct:test and scalastyle. This has turned out to be fairly baroque. Here is my Build.scala from my top-level project/ directory:

object MyBuild extends Build {
  val verifyTask = TaskKey[Unit]("verify", "Compiles, runs tests via scct:test and then runs scalastyle")
  val scctTestTask = (test in ScctPlugin.Scct).scopedKey
  val scalastyleTask = PluginKeys.scalastyleTarget.scopedKey

  lazy val root = Project("rootProject",
                      file("."),
                      settings =  Defaults.defaultSettings ++
                                  ScalastylePlugin.Settings ++
                                  ScctPlugin.instrumentSettings ++
                                  ScctPlugin.mergeReportSettings ++
                                  Seq(
                                    verifyTask in Global := {},
                                    verifyTask <<= verifyTask.dependsOn(scctTestTask, scalastyleTask)
                                  )
              ) aggregate(lift_webapp, selenium_tests)

  lazy val subproject_1 = Project(id = "subproject_1", base = file("subproject_1"))

  lazy val subproject_2 = Project(id = "subproject_2", base = file("subproject_2"))
}

However, the verify task only seems to exist for the root project; when I run it I don't see the same task being run in the subprojects. This is exactly the opposite of what I want; I'd like to issue sbt verify and have scct:test and scalastyle run in each of the subprojects but not in the top-level project. How might I go about doing that?

Answer 1

solution 1: define verifyTask in subprojects

First thing to note is that if you want some task ( verify , test , etc) to run in some projects, you need to define them scoped to the subprojects. So in your case, the most straightforward thing to do this is to define verifyTask in subproject_1 and subproject_2 .

lazy val scalaTest = "org.scalatest" %% "scalatest" % "3.0.4"

lazy val verify = taskKey[Unit]("verify")
def verifySettings = Seq(
  skip in verify := false,
  verify := (Def.taskDyn {
    val sk = (skip in verify).value
    if (sk) Def.task { println("skipping verify...") }
    else (test in Test)
  }).value
)

lazy val root = (project in file("."))
  .aggregate(sub1, sub2)
  .settings(
    verifySettings,
    scalaVersion in ThisBuild := "2.12.4",
    skip in verify := true
  )

lazy val sub1 = (project in file("sub1"))
  .settings(
    verifySettings,
    libraryDependencies += scalaTest % Test
  )

lazy val sub2 = (project in file("sub2"))
  .settings(
    verifySettings,
    libraryDependencies += scalaTest % Test
  )

solution 2: ScopeFilter

There was a recent Reddit thread that mentioned this question, so I'll post what I've done there. If you want to manually aggregate on some subprojects, there's also a technique called ScopeFilter .

Note that I am using sbt 1.x here, but it should work with sbt 0.13 some minor change.

lazy val packageAll = taskKey[Unit]("package all the projects")
lazy val myTask = inputKey[Unit]("foo")

lazy val root = (project in file("."))
  .aggregate(sub1, sub2)
  .settings(
    scalaVersion in ThisBuild := "2.12.4",
    packageAll := {
      (packageBin in Compile).all(nonRootsFilter).value
      ()
    },
    myTask := {
      packageAll.value
    }
  )

lazy val sub1 = (project in file("sub1"))

lazy val sub2 = (project in file("sub2"))

def nonRootsFilter = {
  import sbt.internal.inc.ReflectUtilities
  def nonRoots: List[ProjectReference] =
    allProjects filter {
      case LocalProject(p) => p != "root"
      case _               => false
    }
  def allProjects: List[ProjectReference] =
    ReflectUtilities.allVals[Project](this).values.toList map { p =>
      p: ProjectReference
    }
  ScopeFilter(inProjects(nonRoots: _*), inAnyConfiguration)
}

In the above, myTask depends on packageAll , which aggregates (packageBin in Compile) for all non-root subprojects.

sbt:root> myTask
[info] Packaging /Users/xxx/packageall/sub1/target/scala-2.12/sub1_2.12-0.1.0-SNAPSHOT.jar ...
[info] Done packaging.
[info] Packaging /Users/xxx/packageall/sub2/target/scala-2.12/sub2_2.12-0.1.0-SNAPSHOT.jar ...
[info] Done packaging.
[success] Total time: 0 s, completed Feb 2, 2018 7:23:23 PM

Answer 2

I may be wrong, but you are defining the verify task dependency only for the current project.

Maybe you can try:

Seq(
   verifyTask in Global := {},
   verifyTask <<= (verifyTask in Global).dependsOn(scctTestTask, scalastyleTask)
)

Or you can add the verifyTask settings to all your modules.