Merge pull request #717 from tindzk/issue/716-external-main-classes

Interpreter: Allow to run externally-defined main classes
scalacenter · Nov 14, 2018 · f36ae3d · f36ae3d
2 parents f635679 + 9b1579c
commit f36ae3d
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Showing 2 changed files with 19 additions and 24 deletions.
diff --git a/frontend/src/main/scala/bloop/engine/Feedback.scala b/frontend/src/main/scala/bloop/engine/Feedback.scala
@@ -6,12 +6,10 @@ object Feedback {
   private final val eol = System.lineSeparator
   def listMainClasses(mainClasses: List[String]): String =
     s"Use the following main classes:\n${mainClasses.mkString(" * ", s"$eol * ", "")}"
-  def missingMainClass(project: Project, mainClass: String = ""): String =
-    s"Missing main class $mainClass in project '${project.name}'"
-  def missingDefaultMainClass(project: Project, mainClass: String): String =
-    s"Missing default main class $mainClass in project '${project.name}'"
-  def expectedMainClass(project: Project): String =
-    s"Expected a main class via command-line or in the configuration of project '${project.name}'"
+  def missingMainClass(project: Project): String =
+    s"No main classes defined in project '${project.name}'"
+  def expectedDefaultMainClass(project: Project): String =
+    s"Multiple main classes found. Expected a default main class via command-line or in the configuration of project '${project.name}'"
 
   def missingScalaInstance(project: Project): String =
     s"Failed to compile project '${project.name}': found Scala sources but project is missing Scala configuration."

diff --git a/frontend/src/main/scala/bloop/engine/Interpreter.scala b/frontend/src/main/scala/bloop/engine/Interpreter.scala
@@ -391,27 +391,24 @@ object Interpreter {
       project: Project,
       cliMainClass: Option[String]
   ): Either[State, String] = {
-    Tasks.findMainClasses(state, project) match {
-      case Nil => Left(state.withError(Feedback.missingMainClass(project)))
-      case List(main) => Right(main)
-      case mainClasses =>
-        def withS(msg: String): String = msg.suggest(Feedback.listMainClasses(mainClasses))
-        val configMainClass = project.platform.userMainClass
-        cliMainClass match {
-          case Some(userMainClass) if mainClasses.contains(userMainClass) => Right(userMainClass)
-          case Some(userMainClass) =>
-            Left(state.withError(withS(Feedback.missingMainClass(project, userMainClass))))
+    cliMainClass match {
+      case Some(userMainClass) => Right(userMainClass)
+      case None =>
+        project.platform.userMainClass match {
+          case Some(configMainClass) => Right(configMainClass)
           case None =>
-            configMainClass match {
-              case Some(configMainClass) if mainClasses.contains(configMainClass) =>
-                Right(configMainClass)
-              case Some(configMainClass) =>
-                val msg = withS(Feedback.missingDefaultMainClass(project, configMainClass))
-                Left(state.withError(msg))
-              case None =>
-                val msg = withS(Feedback.expectedMainClass(project))
+            Tasks.findMainClasses(state, project) match {
+              case Nil =>
+                val msg = Feedback.missingMainClass(project)
+                Left(state.withError(msg, ExitStatus.InvalidCommandLineOption))
+              case List(mainClass) => Right(mainClass)
+              case mainClasses =>
+                val msg = Feedback
+                  .expectedDefaultMainClass(project)
+                  .suggest(Feedback.listMainClasses(mainClasses))
                 Left(state.withError(msg, ExitStatus.InvalidCommandLineOption))
             }
+
         }
     }
   }