How can I access sub-projects of an sbt-plugin by using it as dependency in a multi-project build? - scala

Question

I have an sbt plugin project that uses multi-project build. I would like to use this plugin as a dependency for the other sbt project and access sub-project of this sbt plugin. I have created a plugin and I added plugin to an sbt project, but i am not able to access sub-project of plugin there.
sbt-plugin
build.sbt
name := "sbt-plugin"
sbtPlugin := true
val commonSettings = Seq(
organization := "com.example",
version := "1.0",
scalaVersion := "2.11.7",
javacOptions := Seq("-source", "1.8", "-target", "1.8"),
scalacOptions := Seq("-target:jvm-1.8", "-unchecked","-deprecation", "-encoding", "utf8")
)
lazy val root = (project in file("."))
.settings(commonSettings: _*)
.dependsOn(plugin)
.aggregate(plugin)
lazy val plugin = (project in file("plugin"))
.settings(commonSettings: _*)
.settings(
name := "plugin" ,
mainClass in (Compile, run) := Some("com.example.Main")
)
sbt-plugin\plugin\src\main\scala\com\example\Main.scala
package com.example
object Main {
def main(args: Array[String]){
println("Hello from plugin in sbt-plugin");
}
}
sbt-plugin\plugin\src\main\scala\com\example\Hello.scala
package com.example
// Sample code I would like to access from another sbt project
object Hello {
def show = println("Hello, world!")
}
plugin-test
plugin-test is an sbt project which i used to test sbt-plugin
plugin-test\build.sbt
name := """plugin-test"""
val commonSettings = Seq(
version := "1.0",
scalaVersion := "2.11.7",
javacOptions := Seq("-source", "1.8", "-target", "1.8"),
scalacOptions := Seq("-target:jvm-1.8", "-unchecked", "-deprecation", "-encoding", "utf8"),
libraryDependencies += "org.scalatest" %% "scalatest" % "2.2.4" % "test"
)
lazy val root = (project in file("."))
.settings(commonSettings: _*)
.dependsOn(pluginpro)
.aggregate(pluginpro)
.settings(
mainClass in (Compile, run) := Some("com.exam.Test")
)
lazy val pluginpro = (project in file("pluginpro"))
.settings(commonSettings: _*)
.settings(
libraryDependencies += "com.example" % "plugin_2.11" % "1.0"
)
plugin-test\src\main\scala\com\exam\Test.scala
package com.exam
object Test {
def result = com.example.Hello.show()
}
when i run plugin-test project from root it is running but with below mentioned log and i am not sure why is it showing this because according to me output would be only Hello, world!
background log: info: Running com.exam.Test
background log: debug: Waiting for threads to exit or System.exit to be called.
background log: debug: Waiting for thread run-main-0 to terminate.
background log: debug: Classpath:
E:\Play\SBT Plugin\sbt demo1\plugin-test\target\scala-2.11\classes
E:\Play\SBT Plugin\sbt demo1\plugin-test\pluginpro\target\scala-2.11\classes
C:\Users\Jeetu\.ivy2\cache\org.scala-lang\scala-library\jars\scala-library-2.11.7.jar
C:\Users\Jeetu\.ivy2\local\com.example\plugin_2.11\1.0\jars\plugin_2.11.jar
Hello, world!
()
background log: debug: Thread run-main-0 exited.
background log: debug: Interrupting remaining threads (should be all daemons).
background log: debug: Sandboxed run complete..
background log: debug: Exited with code 0
When i try to run sub-project of sbt-plugin via pluginpro/run, it can't find main class.
> pluginpro/run
[trace] Stack trace suppressed: run last pluginpro/compile:backgroundRun for the full output.
[error] (pluginpro/compile:backgroundRun) No main class detected.
i have created main class in sbt-plugin/plugin project.
I performed publish-local and plugin/publish-local on both projects and the artifacts resolved correctly.
What am I missing here?

Answer 1

I resolved it by adding following in build.sbt in pluginpro project:
mainClass in (Compile, run) := Some("com.example.Main")