Minimized test case to reproduce a ScalaTest issue

TargetRefs2.scala

package scalatest_issue

// The following test will not run with Scala 2.11.1 and ScalaTest 2.1.7

import org.scalatest.FreeSpec

object TargetRefs2 {
  def apply(targetRefs: String*): TargetRefs2 = new TargetRefs2(Seq(targetRefs))
}

class TargetRefs2 private (val targetRefGroups: Seq[Seq[String]]) {

  private[this] def closedGroups: Seq[Seq[String]] = targetRefGroups.size match {
    case 1 => Seq()
    case n => targetRefGroups.take(n - 1)
  }

  private[this] def openGroup: Seq[String] = targetRefGroups.lastOption match {
    case Some(last) => last
    case None => Seq()
  }

  def ~(targetRefs: TargetRefs2): TargetRefs2 =
    new TargetRefs2((
      closedGroups ++
      Seq((openGroup ++ targetRefs.targetRefGroups.head).distinct) ++
      targetRefs.targetRefGroups.tail
    ).filter(!_.isEmpty))
  def ~(string: String): TargetRefs2 = this.~(TargetRefs2(string))

  def ~~(targetRefs: TargetRefs2): TargetRefs2 =
    new TargetRefs2((
      targetRefGroups ++
      Seq(targetRefs.targetRefGroups.head) ++
      targetRefs.targetRefGroups.tail
    ).filter(!_.isEmpty))
  def ~~(string: String): TargetRefs2 = ~~(TargetRefs2(string))

  override def toString: String = targetRefGroups.map { _.mkString(" ~ ") }.mkString(" ~~ ")

}

class TargetRefTest2 extends FreeSpec {

  "TargetRefs2 merge" - {

    def mergeTest(refs: TargetRefs2, expected: Seq[Seq[String]]): Unit = {
      s"merge ${refs} to ${expected}" in {
        assert(refs.targetRefGroups === expected)
      }
    }
    mergeTest(TargetRefs2("a"), Seq(Seq("a")))
    mergeTest(TargetRefs2("a") ~ "b", Seq(Seq("a", "b")))
    mergeTest(TargetRefs2("a") ~ "a", Seq(Seq("a"))) 
    mergeTest(TargetRefs2("a") ~~ "a", Seq(Seq("a"), Seq("a")))
  }

Opened issue #334.

Issue was, that test cases had the same name. In all three cases listed above, the toString() was affected resulting in different test names, thus the test ran without issues then.