Run Main.main in current process (#115)

* no message

* fix compile

* fix compile again

* finishing in process running

* remove comment

* fix bug

* fix bug

3 files changed, 37 insertions, 25 deletions

diff --git a/scalalib/src/main/scala/mill/scalalib/ScalaModule.scala b/scalalib/src/main/scala/mill/scalalib/ScalaModule.scala
index 5bae1749..1b2bd28d 100644
--- a/scalalib/src/main/scala/mill/scalalib/ScalaModule.scala
+++ b/scalalib/src/main/scala/mill/scalalib/ScalaModule.scala
@@ -7,7 +7,7 @@ import mill.define.{Cross, Task}
 import mill.define.TaskModule
 import mill.eval.{PathRef, Result}
 import mill.modules.Jvm
-import mill.modules.Jvm.{createAssembly, createJar, interactiveSubprocess, subprocess}
+import mill.modules.Jvm.{createAssembly, createJar, interactiveSubprocess, subprocess, inprocess}
 import Lib._
 import mill.define.Cross.Resolver
 import mill.util.Loose.Agg
@@ -217,7 +217,15 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
 
   def forkArgs = T{ Seq.empty[String] }
 
-  def run(args: String*) = T.command{
+
+  def run(args: String*) = T.command {
+    inprocess(
+      mainClass().getOrElse(throw new RuntimeException("No mainClass provided!")),
+      runClasspath().map(_.path),
+      args)
+  }
+
+  def forkRun(args: String*) = T.command{
     subprocess(
       mainClass().getOrElse(throw new RuntimeException("No mainClass provided!")),
       runClasspath().map(_.path),
diff --git a/scalalib/src/main/scala/mill/scalalib/TestRunner.scala b/scalalib/src/main/scala/mill/scalalib/TestRunner.scala
index 11d9c79f..fa387eef 100644
--- a/scalalib/src/main/scala/mill/scalalib/TestRunner.scala
+++ b/scalalib/src/main/scala/mill/scalalib/TestRunner.scala
@@ -7,6 +7,7 @@ import java.util.zip.ZipInputStream
 
 import ammonite.ops.{Path, ls, pwd}
 import ammonite.util.Colors
+import mill.modules.Jvm
 import mill.util.Ctx.LogCtx
 import mill.util.{PrintLogger}
 import mill.util.Loose.Agg
@@ -74,23 +75,7 @@ object TestRunner {
             testClassfilePath: Agg[Path],
             args: Seq[String])
            (implicit ctx: LogCtx): (String, Seq[Result]) = {
-    val outerClassLoader = getClass.getClassLoader
-
-    val cl = new URLClassLoader(
-      entireClasspath.map(_.toIO.toURI.toURL).toArray,
-      ClassLoader.getSystemClassLoader().getParent()){
-      override def findClass(name: String) = {
-        if (name.startsWith("sbt.testing.")){
-          outerClassLoader.loadClass(name)
-        }else{
-          super.findClass(name)
-        }
-      }
-    }
-
-    val oldCl = Thread.currentThread().getContextClassLoader
-    Thread.currentThread().setContextClassLoader(cl)
-    try {
+    Jvm.inprocess(entireClasspath, classLoaderOverrideSbtTesting = true, cl => {
       val framework = cl.loadClass(frameworkName)
         .newInstance()
         .asInstanceOf[sbt.testing.Framework]
@@ -145,12 +130,7 @@ object TestRunner {
         )
       }
       (doneMsg, results)
-    }finally{
-      Thread.currentThread().setContextClassLoader(oldCl)
-      cl.close()
-    }
-
-
+    })
   }
 
   case class Result(fullyQualifiedName: String,
diff --git a/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala b/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala
index 70c78cee..7444604b 100644
--- a/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala
+++ b/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala
@@ -262,6 +262,30 @@ object HelloWorldTests extends TestSuite {
         )
       }
     }
+
+    'forkRun - {
+      'runIfMainClassProvided - {
+        val runResult = basePath / 'out / 'run / 'dest / "hello-mill"
+        val Right((_, evalCount)) = helloWorldWithMainEvaluator(
+          HelloWorldWithMain.forkRun(runResult.toString)
+        )
+
+        assert(evalCount > 0)
+
+
+        assert(
+          exists(runResult),
+          read(runResult) == "hello rockjam, your age is: 25"
+        )
+      }
+      'notRunWithoutMainClass - {
+        val Left(Result.Exception(err, _)) = helloWorldEvaluator(HelloWorld.forkRun())
+
+        assert(
+          err.isInstanceOf[RuntimeException]
+        )
+      }
+    }
     'run - {
       'runIfMainClassProvided - {
         val runResult = basePath / 'out / 'run / 'dest / "hello-mill"