diff --git a/unittests/map.chai b/unittests/map.chai
index b2901ce..eb7a133 100644
--- a/unittests/map.chai
+++ b/unittests/map.chai
@@ -1,29 +1,41 @@
-assert_equal([true, false, true], map([1,2,3], odd))
+// Map function
+
+{ 
+  assert_equal([true, false, true], map([1,2,3], odd))
+
+  var v = [1, 2, 3];
+  var y = map(v, fun(s) { s*2; });
+  y[0] = 1;
+  assert_equal(1, y[0]);
+} 
 
 
+// Map objects
 
-var m = ["a":1, "b":2];
+{
+  var m = ["a":1, "b":2];
 
-assert_equal(1, m.count("a"))
-assert_equal(0, m.count("c"))
-assert_equal(1, m.erase("a"))
-assert_equal(1, m.size())
-assert_equal(0, m.erase("a"))
+  assert_equal(1, m.count("a"))
+  assert_equal(0, m.count("c"))
+  assert_equal(1, m.erase("a"))
+  assert_equal(1, m.size())
+  assert_equal(0, m.erase("a"))
 
-assert_equal(1, m.size());
+  assert_equal(1, m.size());
 
-var m2 = ["c":3, "b":4]
-m.insert(m2);
+  var m2 = ["c":3, "b":4]
+  m.insert(m2);
 
-assert_equal(3, m["c"])
-// The inserted values do not overwrite the existing ones
-assert_equal(2, m["b"])
-assert_equal(2, m.size())
+  assert_equal(3, m["c"])
+  // The inserted values do not overwrite the existing ones
+  assert_equal(2, m["b"])
+  assert_equal(2, m.size())
 
-var v = "bob";
+  var v = "bob";
 
-m.insert_ref(Map_Pair("d", v))
+  m.insert_ref(Map_Pair("d", v))
 
-assert_equal("bob", m["d"])
-v = "bob2"
-assert_equal("bob2", m["d"])
+  assert_equal("bob", m["d"])
+  v = "bob2"
+  assert_equal("bob2", m["d"])
+}