9 files changed, 181 insertions, 54 deletions
diff --git a/js/binary/decoder.js b/js/binary/decoder.js
index 36828a73..26bf3594 100644
--- a/js/binary/decoder.js
+++ b/js/binary/decoder.js
@@ -942,7 +942,7 @@ jspb.BinaryDecoder.prototype.readEnum = function() {
 /**
  * Reads and parses a UTF-8 encoded unicode string from the stream.
  * The code is inspired by maps.vectortown.parse.StreamedDataViewReader.
- * Supports codepoints from U+0000 up to U+10FFFF. 
+ * Supports codepoints from U+0000 up to U+10FFFF.
  * (http://en.wikipedia.org/wiki/UTF-8).
  * @param {number} length The length of the string to read.
  * @return {string} The decoded string.
@@ -984,7 +984,7 @@ jspb.BinaryDecoder.prototype.readString = function(length) {
       // 4. Add 0xDC00 to the low value to form the low surrogate:
       var low = (codepoint & 1023) + 0xDC00;
       var high = ((codepoint >> 10) & 1023) + 0xD800;
-      codeUnits.push(high, low)
+      codeUnits.push(high, low);
     }
   }
   // String.fromCharCode.apply is faster than manually appending characters on
diff --git a/js/binary/decoder_test.js b/js/binary/decoder_test.js
index 9f947b99..cb8aff96 100644
--- a/js/binary/decoder_test.js
+++ b/js/binary/decoder_test.js
@@ -209,25 +209,25 @@ describe('binaryDecoderTest', function() {
     assertEquals(hashC, decoder.readFixedHash64());
     assertEquals(hashD, decoder.readFixedHash64());
   });
-  
+
   /**
    * Test encoding and decoding utf-8.
    */
    it('testUtf8', function() {
     var encoder = new jspb.BinaryEncoder();
 
-    var ascii = "ASCII should work in 3, 2, 1..."
+    var ascii = "ASCII should work in 3, 2, 1...";
     var utf8_two_bytes = "©";
     var utf8_three_bytes = "❄";
     var utf8_four_bytes = "😁";
-    
+
     encoder.writeString(ascii);
     encoder.writeString(utf8_two_bytes);
     encoder.writeString(utf8_three_bytes);
     encoder.writeString(utf8_four_bytes);
-    
+
     var decoder = jspb.BinaryDecoder.alloc(encoder.end());
-    
+
     assertEquals(ascii, decoder.readString(ascii.length));
     assertEquals(utf8_two_bytes, decoder.readString(utf8_two_bytes.length));
     assertEquals(utf8_three_bytes, decoder.readString(utf8_three_bytes.length));
diff --git a/js/binary/encoder.js b/js/binary/encoder.js
index 1663bbd4..aee33e7e 100644
--- a/js/binary/encoder.js
+++ b/js/binary/encoder.js
@@ -452,9 +452,9 @@ jspb.BinaryEncoder.prototype.writeFixedHash64 = function(hash) {
  */
 jspb.BinaryEncoder.prototype.writeString = function(value) {
   var oldLength = this.buffer_.length;
- 
+
   for (var i = 0; i < value.length; i++) {
-    
+
     var c = value.charCodeAt(i);
 
     if (c < 128) {
diff --git a/js/binary/message_test.js b/js/binary/message_test.js
new file mode 100644
index 00000000..4edc666b
--- /dev/null
+++ b/js/binary/message_test.js
@@ -0,0 +1,60 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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 with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test suite is written using Jasmine -- see http://jasmine.github.io/
+
+goog.setTestOnly();
+
+goog.require('goog.testing.asserts');
+
+// CommonJS-LoadFromFile: test_pb proto.jspb.test
+goog.require('proto.jspb.test.Deeply.Nested.Message');
+
+// CommonJS-LoadFromFile: test2_pb proto.jspb.test
+goog.require('proto.jspb.test.ForeignNestedFieldMessage');
+
+describe('Message test suite', function() {
+  // Verify that we can successfully use a field referring to a nested message
+  // from a different .proto file.
+  it('testForeignNestedMessage', function() {
+    var msg = new proto.jspb.test.ForeignNestedFieldMessage();
+    var nested = new proto.jspb.test.Deeply.Nested.Message();
+    nested.setCount(5);
+    msg.setDeeplyNestedMessage(nested);
+    assertEquals(5, msg.getDeeplyNestedMessage().getCount());
+
+    // After a serialization-deserialization round trip we should get back the
+    // same data we started with.
+    var serialized = msg.serializeBinary();
+    var deserialized =
+        proto.jspb.test.ForeignNestedFieldMessage.deserializeBinary(serialized);
+    assertEquals(5, deserialized.getDeeplyNestedMessage().getCount());
+  });
+});
diff --git a/js/map.js b/js/map.js
index 93f08e03..4f562dbc 100644
--- a/js/map.js
+++ b/js/map.js
@@ -183,26 +183,39 @@ jspb.Map.fromObject = function(entries, valueCtor, valueFromObject) {
 
 
 /**
- * Helper: return an iterator over an array.
+ * Helper: an IteratorIterable over an array.
  * @template T
  * @param {!Array<T>} arr the array
- * @return {!Iterator<T>} an iterator
+ * @implements {IteratorIterable<T>}
+ * @constructor @struct
  * @private
  */
-jspb.Map.arrayIterator_ = function(arr) {
-  var idx = 0;
-  return /** @type {!Iterator} */ ({
-    next: function() {
-      if (idx < arr.length) {
-        return { done: false, value: arr[idx++] };
-      } else {
-        return { done: true };
-      }
-    }
-  });
+jspb.Map.ArrayIteratorIterable_ = function(arr) {
+  /** @type {number} @private */
+  this.idx_ = 0;
+
+  /** @const @private */
+  this.arr_ = arr;
 };
 
 
+/** @override @final */
+jspb.Map.ArrayIteratorIterable_.prototype.next = function() {
+  if (this.idx_ < this.arr_.length) {
+    return {done: false, value: this.arr_[this.idx_++]};
+  } else {
+    return {done: true, value: undefined};
+  }
+};
+
+if (typeof(Symbol) != 'undefined') {
+  /** @override */
+  jspb.Map.ArrayIteratorIterable_.prototype[Symbol.iterator] = function() {
+    return this;
+  };
+}
+
+
 /**
  * Returns the map's length (number of key/value pairs).
  * @return {number}
@@ -260,10 +273,9 @@ jspb.Map.prototype.getEntryList = function() {
 
 
 /**
- * Returns an iterator over [key, value] pairs in the map.
+ * Returns an iterator-iterable over [key, value] pairs in the map.
  * Closure compiler sadly doesn't support tuples, ie. Iterator<[K,V]>.
- * @return {!Iterator<!Array<K|V>>}
- *     The iterator
+ * @return {!IteratorIterable<!Array<K|V>>} The iterator-iterable.
  */
 jspb.Map.prototype.entries = function() {
   var entries = [];
@@ -273,13 +285,13 @@ jspb.Map.prototype.entries = function() {
     var entry = this.map_[strKeys[i]];
     entries.push([entry.key, this.wrapEntry_(entry)]);
   }
-  return jspb.Map.arrayIterator_(entries);
+  return new jspb.Map.ArrayIteratorIterable_(entries);
 };
 
 
 /**
- * Returns an iterator over keys in the map.
- * @return {!Iterator<K>} The iterator
+ * Returns an iterator-iterable over keys in the map.
+ * @return {!IteratorIterable<K>} The iterator-iterable.
  */
 jspb.Map.prototype.keys = function() {
   var keys = [];
@@ -289,13 +301,13 @@ jspb.Map.prototype.keys = function() {
     var entry = this.map_[strKeys[i]];
     keys.push(entry.key);
   }
-  return jspb.Map.arrayIterator_(keys);
+  return new jspb.Map.ArrayIteratorIterable_(keys);
 };
 
 
 /**
- * Returns an iterator over values in the map.
- * @return {!Iterator<V>} The iterator
+ * Returns an iterator-iterable over values in the map.
+ * @return {!IteratorIterable<V>} The iterator-iterable.
  */
 jspb.Map.prototype.values = function() {
   var values = [];
@@ -305,7 +317,7 @@ jspb.Map.prototype.values = function() {
     var entry = this.map_[strKeys[i]];
     values.push(this.wrapEntry_(entry));
   }
-  return jspb.Map.arrayIterator_(values);
+  return new jspb.Map.ArrayIteratorIterable_(values);
 };
 
 
diff --git a/js/maps_test.js b/js/maps_test.js
index 6e6ddc29..e8dd2f21 100755
--- a/js/maps_test.js
+++ b/js/maps_test.js
@@ -288,6 +288,50 @@ function makeTests(msgInfo, submessageCtor, suffix) {
     var a = msg.toArray();
     assertEquals(a[0], entries);  // retains original reference
   });
+
+  /**
+   * Returns IteratorIterables for entries(), keys() and values().
+   */
+  it('testIteratorIterables' + suffix, function() {
+    var msg = new msgInfo.constructor();
+    var m = msg.getMapStringStringMap();
+    m.set('key1', 'value1');
+    m.set('key2', 'value2');
+    var entryIterator = m.entries();
+    assertElementsEquals(entryIterator.next().value, ['key1', 'value1']);
+    assertElementsEquals(entryIterator.next().value, ['key2', 'value2']);
+    assertEquals(entryIterator.next().done, true);
+
+    if (typeof(Symbol) != 'undefined') {
+      var entryIterable = m.entries()[Symbol.iterator]();
+      assertElementsEquals(entryIterable.next().value, ['key1', 'value1']);
+      assertElementsEquals(entryIterable.next().value, ['key2', 'value2']);
+      assertEquals(entryIterable.next().done, true);
+    }
+
+    var keyIterator = m.keys();
+    assertEquals(keyIterator.next().value, 'key1');
+    assertEquals(keyIterator.next().value, 'key2');
+    assertEquals(keyIterator.next().done, true);
+
+    if (typeof(Symbol) != 'undefined') {
+      var keyIterable = m.keys()[Symbol.iterator]();
+      assertEquals(keyIterable.next().value, 'key1');
+      assertEquals(keyIterable.next().value, 'key2');
+      assertEquals(keyIterable.next().done, true);
+    }
+    var valueIterator = m.values();
+    assertEquals(valueIterator.next().value, 'value1');
+    assertEquals(valueIterator.next().value, 'value2');
+    assertEquals(valueIterator.next().done, true);
+
+    if (typeof(Symbol) != 'undefined') {
+      var valueIterable = m.values()[Symbol.iterator]();
+      assertEquals(valueIterable.next().value, 'value1');
+      assertEquals(valueIterable.next().value, 'value2');
+      assertEquals(valueIterable.next().done, true);
+    }
+  });
 }
 
 describe('mapsTest', function() {
diff --git a/js/message.js b/js/message.js
index 1eb88aef..05d34e9d 100644
--- a/js/message.js
+++ b/js/message.js
@@ -175,6 +175,22 @@ goog.define('jspb.Message.GENERATE_FROM_OBJECT', !goog.DISALLOW_TEST_ONLY_CODE);
 
 
 /**
+ * @define {boolean} Whether to generate toString methods for objects. Turn
+ *     this off if you do use toString in your project and want to trim it from
+ *     compiled JS.
+ */
+goog.define('jspb.Message.GENERATE_TO_STRING', true);
+
+
+/**
+ * @define {boolean} Whether arrays passed to initialize() can be assumed to be
+ *     local (e.g. not from another iframe) and thus safely classified with
+ *     instanceof Array.
+ */
+goog.define('jspb.Message.ASSUME_LOCAL_ARRAYS', false);
+
+
+/**
  * @define {boolean} Turning on this flag does NOT change the behavior of JSPB
  *     and only affects private internal state. It may, however, break some
  *     tests that use naive deeply-equals algorithms, because using a proto
@@ -364,6 +380,18 @@ jspb.Message.EMPTY_LIST_SENTINEL_ = goog.DEBUG && Object.freeze ?
 
 
 /**
+ * Returns true if the provided argument is an array.
+ * @param {*} o The object to classify as array or not.
+ * @return {boolean} True if the provided object is an array.
+ * @private
+ */
+jspb.Message.isArray_ = function(o) {
+  return jspb.Message.ASSUME_LOCAL_ARRAYS ? o instanceof Array :
+                                            goog.isArray(o);
+};
+
+
+/**
  * Ensures that the array contains an extension object if necessary.
  * If the array contains an extension object in its last position, then the
  * object is kept in place and its position is used as the pivot.  If not, then
@@ -383,8 +411,8 @@ jspb.Message.materializeExtensionObject_ = function(msg, suggestedPivot) {
     // the object is not an array, since arrays are valid field values.
     // NOTE(lukestebbing): We avoid looking at .length to avoid a JIT bug
     // in Safari on iOS 8. See the description of CL/86511464 for details.
-    if (obj && typeof obj == 'object' && !goog.isArray(obj) &&
-       !(jspb.Message.SUPPORTS_UINT8ARRAY_ && obj instanceof Uint8Array)) {
+    if (obj && typeof obj == 'object' && !jspb.Message.isArray_(obj) &&
+        !(jspb.Message.SUPPORTS_UINT8ARRAY_ && obj instanceof Uint8Array)) {
       msg.pivot_ = foundIndex - msg.arrayIndexOffset_;
       msg.extensionObject_ = obj;
       return;
@@ -1140,6 +1168,7 @@ jspb.Message.prototype.toArray = function() {
 
 
 
+if (jspb.Message.GENERATE_TO_STRING) {
 
 /**
  * Creates a string representation of the internal data array of this proto.
@@ -1152,6 +1181,7 @@ jspb.Message.prototype.toString = function() {
   return this.array.toString();
 };
 
+}
 
 /**
  * Gets the value of the extension field from the extended object.
diff --git a/js/message_test.js b/js/message_test.js
index 6d7cdd21..a2c5763d 100644
--- a/js/message_test.js
+++ b/js/message_test.js
@@ -76,12 +76,10 @@ goog.require('proto.jspb.test.TestGroup1');
 goog.require('proto.jspb.test.TestMessageWithOneof');
 goog.require('proto.jspb.test.TestReservedNames');
 goog.require('proto.jspb.test.TestReservedNamesExtension');
-goog.require('proto.jspb.test.Deeply.Nested.Message');
 
 // CommonJS-LoadFromFile: test2_pb proto.jspb.test
 goog.require('proto.jspb.test.ExtensionMessage');
 goog.require('proto.jspb.test.TestExtensionsMessage');
-goog.require('proto.jspb.test.ForeignNestedFieldMessage');
 
 
 
@@ -1053,21 +1051,4 @@ describe('Message test suite', function() {
     assertNan(message.getDefaultDoubleField());
   });
 
-  // Verify that we can successfully use a field referring to a nested message
-  // from a different .proto file.
-  it('testForeignNestedMessage', function() {
-    var msg = new proto.jspb.test.ForeignNestedFieldMessage();
-    var nested = new proto.jspb.test.Deeply.Nested.Message();
-    nested.setCount(5);
-    msg.setDeeplyNestedMessage(nested);
-    assertEquals(5, msg.getDeeplyNestedMessage().getCount());
-
-    // After a serialization-deserialization round trip we should get back the
-    // same data we started with.
-    var serialized = msg.serializeBinary();
-    var deserialized =
-        proto.jspb.test.ForeignNestedFieldMessage.deserializeBinary(serialized);
-    assertEquals(5, deserialized.getDeeplyNestedMessage().getCount());
-  });
-
 });
diff --git a/js/package.json b/js/package.json
index d3c77eb6..dd6373de 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-protobuf",
-  "version": "3.1.0",
+  "version": "3.2.0",
   "description": "Protocol Buffers for JavaScript",
   "main": "google-protobuf.js",
   "files": [