ES6 Map/Set iterators/forEach improvements

test/mjsunit/harmony/collections.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 834 matching lines @@
 
   var accumulated = 0;
   map.forEach(function(v) {
     accumulated += v;
     if (v % 10 === 0) {
       gc();
     }
   });
   assertEquals(4950, accumulated);
 })();
+
+
+(function TestMapForEachAllRemovedTransition() {
+  var map = new Map;
+  map.set(0, 0);
+
+  var buffer = [];
+  map.forEach(function(v) {
+    buffer.push(v);
+    if (v === 0) {
+      for (var i = 1; i < 4; i++) {
+        map.set(i, i);
+      }
+    }
+
+    if (v === 3) {
+      for (var i = 0; i < 4; i++) {
+        map.delete(i);
+      }
+      for (var i = 4; i < 8; i++) {
+        map.set(i, i);
+      }
+    }
+  });
+
+  assertArrayEquals([0, 1, 2, 3, 4, 5, 6, 7], buffer);
+})();
+
+
+(function TestMapForEachClearTransition() {
+  var map = new Map;
+  map.set(0, 0);
+
+  var i = 0;
+  var buffer = [];
+  map.forEach(function(v) {
+    buffer.push(v);
+    if (++i < 5) {
+      for (var j = 0; j < 5; j++) {
+        map.clear();
+        map.set(i, i);
+      }
+    }
+  });
+
+  assertArrayEquals([0, 1, 2, 3, 4], buffer);
+})();