Add scripted tests

sbt/src/sbt-test/tests/fork-test-group-parallel-custom-tags/build.sbt

@@ -0,0 +1,33 @@
+val specs = "org.specs2" %% "specs2-core" % "4.3.4"
+ThisBuild / scalaVersion := "2.12.11"
+
+val TestATypeTag = Tags.Tag("TestA")
+val TestBTypeTag = Tags.Tag("TestB")
+
+Global / concurrentRestrictions := Seq(Tags.limit(TestATypeTag, 1), Tags.limit(TestBTypeTag, 1))
+
+libraryDependencies += specs % Test
+inConfig(Test)(Seq(
+  testGrouping := {
+    val home = javaHome.value
+    val strategy = outputStrategy.value
+    val baseDir = baseDirectory.value
+    val options = javaOptions.value
+    val connect = connectInput.value
+    val vars = envVars.value
+
+    definedTests.value.map { test => new Tests.Group(test.name, Seq(test), Tests.SubProcess(
+      ForkOptions(
+        javaHome = home,
+        outputStrategy = strategy,
+        bootJars = Vector(),
+        workingDirectory = Some(baseDir),
+        runJVMOptions = options.toVector,
+        connectInput = connect,
+        envVars = vars
+      )
+    ), Seq((if (test.name.contains("TestA")) TestATypeTag else TestBTypeTag) -> 1))
+    }
+  },
+  TaskKey[Unit]("test-failure") := test.failure.value
+))

sbt/src/sbt-test/tests/fork-test-group-parallel-custom-tags/src/test/scala/example/Test.scala

@@ -0,0 +1,33 @@
+package example
+
+import java.io.File
+import org.specs2.mutable.Specification
+
+trait Test extends Specification {
+  def testType: String
+  "spec" should {
+    "be run one at time" in {
+      val lock = new File(s"lock${testType}")
+      println(lock)
+      lock.mkdir() should beTrue
+      Thread.sleep(2000)
+      lock.delete() should beTrue
+    }
+  }
+}
+
+class TestA0 extends Test {
+  override def testType: String = "A"
+}
+
+class TestA1 extends Test {
+  override def testType: String = "A"
+}
+
+class TestB0 extends Test {
+  override def testType: String = "B"
+}
+
+class TestB1 extends Test {
+  override def testType: String = "B"
+}

sbt/src/sbt-test/tests/fork-test-group-parallel-custom-tags/test

@@ -0,0 +1,3 @@
+> test
+> set concurrentRestrictions in Global := Seq(Tags.limitAll(4))
+> testFailure