Applied performance patch and test case from ij...

Applied performance patch and test case from ijuma; closes #2526.

1 files changed, 54 insertions, 0 deletions

diff --git a/test/files/run/t2526.scala b/test/files/run/t2526.scala
new file mode 100644
index 0000000000..5f6d60546a
--- /dev/null
+++ b/test/files/run/t2526.scala
@@ -0,0 +1,54 @@
+/**
+ * Checks that various foreach methods overridden in mutable.HashMap as part of ticket #2526
+ * still work correctly.
+ */
+object Test {
+  import collection._
+
+  def main(args: Array[String]) {
+    val m = new mutable.HashMap[String, String]
+
+    /* Use non hash-based structure for verification */
+    val keys = List("a", "b", "c", "d", "e")
+    val valueSuffix = "value"
+    val values = keys.map(_ + valueSuffix)
+    val entries = keys.zip(values)
+
+    for (k <- keys) m(k) = k + valueSuffix
+
+    assertForeach(keys, m.keySet.iterator)
+    assertForeach(keys, m.keysIterator)
+    assertForeach(keys, m.keySet)
+
+    assertForeach(values, m.valuesIterable.iterator)
+    assertForeach(values, m.valuesIterator)
+    assertForeach(values, m.valuesIterable)
+
+    assertForeach(entries, m)
+  }
+
+  /* Checks foreach of `actual` goes over all the elements in `expected` */
+  private def assertForeach[E](expected: Traversable[E], actual: Iterator[E]): Unit = {
+    val notYetFound = new mutable.ArrayBuffer[E]() ++= expected
+    actual.foreach { e =>
+      assert(notYetFound.contains(e))
+      notYetFound -= e
+    }
+    assert(notYetFound.size == 0, "mutable.HashMap.foreach should have iterated over: " + notYetFound)
+  }
+
+  /*
+   * Checks foreach of `actual` goes over all the elements in `expected`
+   * We duplicate the method above because there is no common inteface between Traverable and
+   * Iterator and we want to avoid converting between collections to ensure that we test what
+   * we mean to test.
+   */
+  private def assertForeach[E](expected: Traversable[E], actual: Traversable[E]): Unit = {
+    val notYetFound = new mutable.ArrayBuffer[E]() ++= expected
+    actual.foreach { e =>
+      assert(notYetFound.contains(e))
+      notYetFound -= e
+    }
+    assert(notYetFound.size == 0, "mutable.HashMap.foreach should have iterated over: " + notYetFound)
+  }
+}