Put idempotency tests in their own category

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -293,30 +293,6 @@ class CompilationTests extends ParallelTesting {
     tests.foreach(_.delete())
   }
 
-  /** Add a `z` so that they run last. TODO: Only run them selectively? */
-  @Test def zBytecodeIdempotency: Unit = {
-    val opt = defaultOptions.and("-YemitTasty")
-
-    def idempotency1() = {
-      compileDir("../collection-strawman/src/main", opt) +
-      compileFilesInDir("../tests/pos", opt)
-    }
-    def idempotency2() = {
-      compileDir("../collection-strawman/src/main", opt) +
-      compileFilesInDir("../tests/pos", opt)
-    }
-
-    val tests = (idempotency1() + idempotency2()).keepOutput.checkCompile()
-
-    assert(new java.io.File("../out/idempotency1/").exists)
-    assert(new java.io.File("../out/idempotency2/").exists)
-
-    compileList("idempotency", List("../tests/idempotency/Checker.scala", "../tests/idempotency/IdempotencyCheck.scala"), defaultOptions).checkRuns()
-
-    tests.delete()
-  }
-
-
   private val (compilerSources, backendSources, backendJvmSources) = {
     def sources(paths: JStream[Path], excludedFiles: List[String] = Nil): List[String] =
       paths.iterator().asScala

compiler/test/dotty/tools/dotc/IdempotencyTests.scala

@@ -0,0 +1,52 @@
+package dotty
+package tools
+package dotc
+
+import org.junit.{ Test, AfterClass }
+
+import scala.concurrent.duration._
+
+import vulpix.{ ParallelTesting, SummaryReport, SummaryReporting, TestConfiguration }
+
+
+class IdempotencyTests extends ParallelTesting {
+  import TestConfiguration._
+  import IdempotencyTests._
+
+  // Test suite configuration --------------------------------------------------
+
+  def maxDuration = 30.seconds
+  def numberOfSlaves = 5
+  def safeMode = Properties.testsSafeMode
+  def isInteractive = SummaryReport.isInteractive
+  def testFilter = Properties.testsFilter
+
+  /* TODO: Only run them selectively? */
+  @Test def bytecodeIdempotency: Unit = {
+    val opt = defaultOptions.and("-YemitTasty")
+
+    def idempotency1() = {
+      compileDir("../collection-strawman/src/main", opt) +
+      compileFilesInDir("../tests/pos", opt)
+    }
+    def idempotency2() = {
+      compileDir("../collection-strawman/src/main", opt) +
+      compileFilesInDir("../tests/pos", opt)
+    }
+
+    val tests = (idempotency1() + idempotency2()).keepOutput.checkCompile()
+
+    assert(new java.io.File("../out/idempotency1/").exists)
+    assert(new java.io.File("../out/idempotency2/").exists)
+
+    compileList("idempotency", List("../tests/idempotency/Checker.scala", "../tests/idempotency/IdempotencyCheck.scala"), defaultOptions).checkRuns()
+
+    tests.delete()
+  }
+
+}
+
+object IdempotencyTests {
+  implicit val summaryReport: SummaryReporting = new SummaryReport
+  @AfterClass def cleanup(): Unit = summaryReport.echoSummary()
+}