1 files changed, 34 insertions, 0 deletions
diff --git a/test/junit/scala/collection/mutable/TreeMapTest.scala b/test/junit/scala/collection/mutable/TreeMapTest.scala
new file mode 100644
index 0000000000..ce79621c6f
--- /dev/null
+++ b/test/junit/scala/collection/mutable/TreeMapTest.scala
@@ -0,0 +1,34 @@
+package scala.collection.mutable
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+import scala.collection.mutable
+
+@RunWith(classOf[JUnit4])
+class TreeMapTest {
+
+  @Test
+  def rangeMkString() {
+
+    val map = mutable.TreeMap[String, String]()
+
+    List("a", "b", "c", "d").foreach(v => map.put(v, v))
+
+    val range = map.range("b", "c")
+
+    val valuesRange = range.values
+    val keysRange = range.keys
+
+    assertEquals(1, valuesRange.size)
+    assertEquals(1, keysRange.size)
+
+    assertEquals("b", valuesRange.mkString(","))
+    assertEquals("b", keysRange.mkString(","))
+    assertEquals("b -> b", range.mkString(","))
+
+  }
+
+}