workaround for ScalaMeter incorrect report path

The ScalaMeter issue is reported here:

https://github.com/scalameter/scalameter/pull/163/files

The issue exists both in v0.7 and v0.6. As dotty uses v0.6 now,
use this workaround until we upgrate to a new version of ScalaMeter.

Author: liufengyun

bench/src/test/scala/TestsAsBenchmarks.scala

@@ -5,18 +5,48 @@ import java.lang.reflect.Method
 
 import org.junit.runner.Request
 import org.junit.runner.notification.RunNotifier
+import org.scalameter.Key.reports._
 import org.scalameter.PerformanceTest.OnlineRegressionReport
 import org.scalameter.api._
+import org.scalameter.{Context, History, persistence, currentContext}
 import org.scalameter.reporting.RegressionReporter.Tester
 
 import scala.collection.mutable.ListBuffer
 
+// decorator of persitor to expose info for debugging
+class DecoratorPersistor(p: Persistor) extends SerializationPersistor {
+
+  override def load(context: Context): History = {
+    val resultdir = currentContext(resultDir)
+    val scope = context.scope
+    val curve = context.curve
+    val fileName = s"$resultdir$sep$scope.$curve.dat"
+
+    println(s"load file $fileName")
+
+    p.load(context)
+  }
+
+  override def save(context: Context, h: History) = {
+    val resultdir = currentContext(resultDir)
+    val scope = context.scope
+    val curve = context.curve
+    val fileName = s"$resultdir$sep$scope.$curve.dat"
+
+    println(s"save file $fileName")
+
+    p.save(context, h)
+  }
+}
 
 abstract class TestsToBenchmarkConverter
 (targetClass: Class[_],
  filterAnnot: Class[_ <: java.lang.annotation.Annotation] = classOf[org.junit.Test].asInstanceOf[Class[_ <: java.lang.annotation.Annotation]])
   extends OnlineRegressionReport {
 
+  // NOTE: use `val persistor = ...` would cause persistor ignore command line options for `resultDir`
+  override def persistor = new DecoratorPersistor(super.persistor)
+
   // accept all the results, do not fail
   override def tester: Tester = new Tester.Accepter
 
@@ -29,15 +59,31 @@ abstract class TestsToBenchmarkConverter
     (name, Gen.single("test")(name).map(Request.method(targetClass, _).getRunner))}.toMap
   //Gen.enumeration("test")(testNames:_*)
 
-  performance of targetClass.getSimpleName config (Context(reports.resultDir -> "./tmp")) in {
-    for (test <- testNames)
-      measure.method(test) in {
-        using(tests(test)) curve test in {
-          r =>
-            val dummy = new RunNotifier()
-            r.run(dummy)
+  def setup =
+    performance of targetClass.getSimpleName in {
+      for (test <- testNames)
+        measure.method(test) in {
+          using(tests(test)) curve test in {
+            r =>
+              val dummy = new RunNotifier()
+              r.run(dummy)
+          }
         }
-      }
+    }
+
+  /** workaround to fix problem in ScalaMeter
+    *
+    * NOTE: Otherwise, command line options would be ignored by HTMLReporter, as
+    *       the HTMLReporter uses the context of tree node, which is created via
+    *       ScalaMeter DSL before command line option `-CresultDir` takes effect
+    *       in `PerformanceTest.main`.
+    *
+    *       Following code ensures that the test tree is set up after the `-CresultDir`
+    *       option takes effect.
+    **/
+  override def executeTests(): Boolean = {
+    setup
+    super.executeTests()
   }
 
   def getMethodsAnnotatedWith(clazz: Class[_], annotation: Class[_ <: java.lang.annotation.Annotation]): List[Method] = {

project/Build.scala

@@ -239,7 +239,6 @@ object DottyBuild extends Build {
 
       libraryDependencies ++= Seq("com.storm-enroute" %% "scalameter" % "0.6" % Test,
         "com.novocode" % "junit-interface" % "0.11"),
-      testFrameworks += new TestFramework("org.scalameter.ScalaMeterFramework"),
 
       fork in Test := true,
       parallelExecution in Test := false,