mainClass support

2 files changed, 23 insertions, 2 deletions

diff --git a/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala b/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala
index 6b67b708..b87ba6b3 100644
--- a/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala
+++ b/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala
@@ -224,6 +224,7 @@ trait ScalaModule extends Module with TaskModule{ outer =>
     override def projectDeps = Seq(outer)
   }
   def scalaVersion: T[String]
+  def mainClass: T[Option[String]] = None
 
   def scalaBinaryVersion = T{ scalaVersion().split('.').dropRight(1).mkString(".") }
   def ivyDeps = T{ Seq[Dep]() }
@@ -349,7 +350,7 @@ trait ScalaModule extends Module with TaskModule{ outer =>
   def classpath = T{ Seq(resources(), compile()) }
   def jar = T{
     val dest = T.ctx().dest
-    createJar(dest, Seq(resources(), compile()).map(_.path).filter(exists))
+    createJar(dest, Seq(resources(), compile()).map(_.path).filter(exists), mainClass())
     PathRef(dest)
   }
 
diff --git a/scalaplugin/src/test/scala/mill/scalaplugin/HelloWorldTests.scala b/scalaplugin/src/test/scala/mill/scalaplugin/HelloWorldTests.scala
index 03b9b285..f4a4e993 100644
--- a/scalaplugin/src/test/scala/mill/scalaplugin/HelloWorldTests.scala
+++ b/scalaplugin/src/test/scala/mill/scalaplugin/HelloWorldTests.scala
@@ -17,6 +17,10 @@ trait HelloWorldModule extends ScalaModule {
 
 object HelloWorld extends HelloWorldModule
 
+object HelloWorldWithMain extends HelloWorldModule {
+  override def mainClass = Some("Main")
+}
+
 object HelloWorldWarnUnused extends HelloWorldModule {
   override def scalacOptions = T(Seq("-Ywarn-unused"))
 }
@@ -200,7 +204,23 @@ object HelloWorldTests extends TestSuite {
           jarFiles.forall(expectedFiles.contains)
         )
       }
-      // TODO: check that we can `java -jar` produced jar
+      'runJar - {
+        val Right((result, evalCount)) =
+          eval(HelloWorldWithMain.jar, Discovered.mapping(HelloWorldWithMain))
+
+        assert(
+          exists(result.path),
+          evalCount > 0
+        )
+
+        %("scala", result.path)
+
+        val runResult = workspacePath / "hello-mill"
+        assert(
+          exists(runResult),
+          read(runResult) == "hello rockjam, your age is: 25"
+        )
+      }
     }
   }