Expose the content of Maps and WeakMaps through MapMirror.

test/mjsunit/harmony/mirror-collections.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-debug-as debug --expose-gc --harmony-collections
+
+function testMapMirror(mirror) {
+  // Create JSON representation.
+  var serializer = debug.MakeMirrorSerializer();
+  var json = JSON.stringify(serializer.serializeValue(mirror));
+
+  // Check the mirror hierachy.
+  assertTrue(mirror instanceof debug.Mirror);
+  assertTrue(mirror instanceof debug.ValueMirror);
+  assertTrue(mirror instanceof debug.ObjectMirror);
+  assertTrue(mirror instanceof debug.MapMirror);
+
+  assertTrue(mirror.isMap());
+
+  // Parse JSON representation and check.
+  var fromJSON = eval('(' + json + ')');
+  assertEquals('map', fromJSON.type);
+}
+
+var o1 = new Object();
+var o2 = new Object();
+var o3 = new Object();
+
+// Test the mirror object for Maps
+var map = new Map();
+map.set(o1, 11);
+map.set(o2, 22);
+map.delete(o1);
+var mapMirror = debug.MakeMirror(map);
+testMapMirror(mapMirror);
+var entries = mapMirror.entries();
+assertEquals(1, entries.length);
+assertSame(o2, entries[0].key);
+assertEquals(22, entries[0].value);
+map.set(o1, 33);
+map.set(o3, o2);
+map.delete(o2);
+map.set(undefined, 44);
+entries = mapMirror.entries();
+assertEquals(3, entries.length);
+assertSame(o1, entries[0].key);
+assertEquals(33, entries[0].value);
+assertSame(o3, entries[1].key);
+assertSame(o2, entries[1].value);
+assertEquals(undefined, entries[2].key);
+assertEquals(44, entries[2].value);
+
+// Test the mirror object for WeakMaps
+var weakMap = new WeakMap();
+weakMap.set(o1, 11);
+weakMap.set(new Object(), 22);
+weakMap.set(o3, 33);
+weakMap.set(new Object(), 44);
+var weakMapMirror = debug.MakeMirror(weakMap);
+testMapMirror(weakMapMirror);
+weakMap.set(new Object(), 55);
+assertTrue(weakMapMirror.entries().length <= 5);
+gc();
+
+function testWeakMapEntries(weakMapMirror) {
+  var entries = weakMapMirror.entries();
+  assertEquals(2, entries.length);
+  var found = 0;
+  for (var i = 0; i < entries.length; i++) {
+    if (Object.is(entries[i].key, o1)) {
+      assertEquals(11, entries[i].value);
+      found++;
+    }
+    if (Object.is(entries[i].key, o3)) {
+      assertEquals(33, entries[i].value);
+      found++;
+    }
+  }
+  assertEquals(2, found);
+}
+
+testWeakMapEntries(weakMapMirror);