diff --git a/js/message_test.js b/js/message_test.js
new file mode 100644
index 0000000..971ea4f
--- /dev/null
+++ b/js/message_test.js
@@ -0,0 +1,974 @@
+// 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.json');
+goog.require('goog.testing.asserts');
+goog.require('jspb.Message');
+goog.require('proto.jspb.exttest.beta.floatingStrField');
+goog.require('proto.jspb.exttest.floatingMsgField');
+goog.require('proto.jspb.exttest.floatingMsgFieldTwo');
+goog.require('proto.jspb.test.CloneExtension');
+goog.require('proto.jspb.test.Complex');
+goog.require('proto.jspb.test.DefaultValues');
+goog.require('proto.jspb.test.Empty');
+goog.require('proto.jspb.test.EnumContainer');
+goog.require('proto.jspb.test.ExtensionMessage');
+goog.require('proto.jspb.test.floatingMsgField');
+goog.require('proto.jspb.test.floatingStrField');
+goog.require('proto.jspb.test.HasExtensions');
+goog.require('proto.jspb.test.IndirectExtension');
+goog.require('proto.jspb.test.IsExtension');
+goog.require('proto.jspb.test.OptionalFields');
+goog.require('proto.jspb.test.OuterEnum');
+goog.require('proto.jspb.test.simple1');
+goog.require('proto.jspb.test.Simple1');
+goog.require('proto.jspb.test.Simple2');
+goog.require('proto.jspb.test.SpecialCases');
+goog.require('proto.jspb.test.TestClone');
+goog.require('proto.jspb.test.TestExtensionsMessage');
+goog.require('proto.jspb.test.TestGroup');
+goog.require('proto.jspb.test.TestGroup1');
+goog.require('proto.jspb.test.TestMessageWithOneof');
+goog.require('proto.jspb.test.TestReservedNames');
+goog.require('proto.jspb.test.TestReservedNamesExtension');
+
+
+
+
+describe('Message test suite', function() {
+  it('testEmptyProto', function() {
+    var empty1 = new proto.jspb.test.Empty([]);
+    var empty2 = new proto.jspb.test.Empty([]);
+    assertObjectEquals({}, empty1.toObject());
+    assertObjectEquals('Message should not be corrupted:', empty2, empty1);
+  });
+
+  it('testTopLevelEnum', function() {
+    var response = new proto.jspb.test.EnumContainer([]);
+    response.setOuterEnum(proto.jspb.test.OuterEnum.FOO);
+    assertEquals(proto.jspb.test.OuterEnum.FOO, response.getOuterEnum());
+  });
+
+  it('testByteStrings', function() {
+    var data = new proto.jspb.test.DefaultValues([]);
+    data.setBytesField('some_bytes');
+    assertEquals('some_bytes', data.getBytesField());
+  });
+
+  it('testComplexConversion', function() {
+    var data1 = ['a',,, [, 11], [[, 22], [, 33]],, ['s1', 's2'],, 1];
+    var data2 = ['a',,, [, 11], [[, 22], [, 33]],, ['s1', 's2'],, 1];
+    var foo = new proto.jspb.test.Complex(data1);
+    var bar = new proto.jspb.test.Complex(data2);
+    var result = foo.toObject();
+    assertObjectEquals({
+      aString: 'a',
+      anOutOfOrderBool: 1,
+      aNestedMessage: {
+        anInt: 11
+      },
+      aRepeatedMessageList: [{anInt: 22}, {anInt: 33}],
+      aRepeatedStringList: ['s1', 's2']
+    }, result);
+
+    // Now test with the jspb instances included.
+    result = foo.toObject(true /* opt_includeInstance */);
+    assertObjectEquals({
+      aString: 'a',
+      anOutOfOrderBool: 1,
+      aNestedMessage: {
+        anInt: 11,
+        $jspbMessageInstance: foo.getANestedMessage()
+      },
+      aRepeatedMessageList: [
+        {anInt: 22, $jspbMessageInstance: foo.getARepeatedMessageList()[0]},
+        {anInt: 33, $jspbMessageInstance: foo.getARepeatedMessageList()[1]}
+      ],
+      aRepeatedStringList: ['s1', 's2'],
+      $jspbMessageInstance: foo
+    }, result);
+
+  });
+
+  it('testMissingFields', function() {
+    var foo = new proto.jspb.test.Complex([
+        undefined, undefined, undefined, [],
+        undefined, undefined, undefined, undefined]);
+    var bar = new proto.jspb.test.Complex([
+        undefined, undefined, undefined, [],
+        undefined, undefined, undefined, undefined]);
+    var result = foo.toObject();
+    assertObjectEquals({
+      aString: undefined,
+      anOutOfOrderBool: undefined,
+      aNestedMessage: {
+        anInt: undefined
+      },
+      // Note: JsPb converts undefined repeated fields to empty arrays.
+      aRepeatedMessageList: [],
+      aRepeatedStringList: []
+    }, result);
+
+  });
+
+  it('testSpecialCases', function() {
+    // Note: Some property names are reserved in JavaScript.
+    // These names are converted to the Js property named pb_<reserved_name>.
+    var special =
+        new proto.jspb.test.SpecialCases(['normal', 'default', 'function',
+        'var']);
+    var result = special.toObject();
+    assertObjectEquals({
+      normal: 'normal',
+      pb_default: 'default',
+      pb_function: 'function',
+      pb_var: 'var'
+    }, result);
+  });
+
+  it('testDefaultValues', function() {
+    var defaultString = "default<>\'\"abc";
+    var response = new proto.jspb.test.DefaultValues();
+
+    // Test toObject
+    var expectedObject = {
+      stringField: defaultString,
+      boolField: true,
+      intField: 11,
+      enumField: 13,
+      emptyField: '',
+      bytesField: 'bW9v'
+    };
+    assertObjectEquals(expectedObject, response.toObject());
+
+
+    // Test getters
+    response = new proto.jspb.test.DefaultValues();
+    assertEquals(defaultString, response.getStringField());
+    assertEquals(true, response.getBoolField());
+    assertEquals(11, response.getIntField());
+    assertEquals(13, response.getEnumField());
+    assertEquals('', response.getEmptyField());
+    assertEquals('bW9v', response.getBytesField());
+
+    function makeDefault(values) {
+      return new proto.jspb.test.DefaultValues(values);
+    }
+
+    // Test with undefined values,
+    // Use push to workaround IE treating undefined array elements as holes.
+    response = makeDefault([undefined, undefined, undefined, undefined]);
+    assertEquals(defaultString, response.getStringField());
+    assertEquals(true, response.getBoolField());
+    assertEquals(11, response.getIntField());
+    assertEquals(13, response.getEnumField());
+
+    // Test with null values, as would be returned by a JSON serializer.
+    response = makeDefault([null, null, null, null]);
+    assertEquals(defaultString, response.getStringField());
+    assertEquals(true, response.getBoolField());
+    assertEquals(11, response.getIntField());
+    assertEquals(13, response.getEnumField());
+
+    // Test with false-like values.
+    response = makeDefault(['', false, 0, 0]);
+    assertEquals('', response.getStringField());
+    assertEquals(false, response.getBoolField());
+    assertEquals(true, response.getIntField() == 0);
+    assertEquals(true, response.getEnumField() == 0);
+
+    // Test that clearing the values reverts them to the default state.
+    response = makeDefault(['blah', false, 111, 77]);
+    response.clearStringField(); response.clearBoolField();
+    response.clearIntField(); response.clearEnumField();
+    assertEquals(defaultString, response.getStringField());
+    assertEquals(true, response.getBoolField());
+    assertEquals(11, response.getIntField());
+    assertEquals(13, response.getEnumField());
+
+    // Test that setFoo(null) clears the values.
+    response = makeDefault(['blah', false, 111, 77]);
+    response.setStringField(null); response.setBoolField(null);
+    response.setIntField(undefined); response.setEnumField(undefined);
+    assertEquals(defaultString, response.getStringField());
+    assertEquals(true, response.getBoolField());
+    assertEquals(11, response.getIntField());
+    assertEquals(13, response.getEnumField());
+  });
+
+  it('testMessageRegistration', function() {
+    // goog.require(SomeResponse) will include its library, which will in
+    // turn add SomeResponse to the message registry.
+    assertEquals(jspb.Message.registry_['res'], proto.jspb.test.SomeResponse);
+  });
+
+  it('testClearFields', function() {
+    // We don't set 'proper' defaults, rather, bools, strings,
+    // etc, are cleared to undefined or null and take on the Javascript
+    // meaning for that value. Repeated fields are set to [] when cleared.
+    var data = ['str', true, [11], [[22], [33]], ['s1', 's2']];
+    var foo = new proto.jspb.test.OptionalFields(data);
+    foo.clearAString();
+    foo.clearABool();
+    foo.clearANestedMessage();
+    foo.clearARepeatedMessageList();
+    foo.clearARepeatedStringList();
+    assertUndefined(foo.getAString());
+    assertUndefined(foo.getABool());
+    assertUndefined(foo.getANestedMessage());
+    assertObjectEquals([], foo.getARepeatedMessageList());
+    assertObjectEquals([], foo.getARepeatedStringList());
+    // NOTE: We want the missing fields in 'expected' to be undefined,
+    // but we actually get a sparse array instead. We could use something
+    // like [1,undefined,2] to avoid this, except that this is still
+    // sparse on IE. No comment...
+    var expected = [,,, [], []];
+    expected[0] = expected[1] = expected[2] = undefined;
+    assertObjectEquals(expected, foo.toArray());
+
+    // Test set(null). We could deprecated this in favor of clear(), but
+    // it's also convenient to have.
+    data = ['str', true, [11], [[22], [33]], ['s1', 's2']];
+    foo = new proto.jspb.test.OptionalFields(data);
+    foo.setAString(null);
+    foo.setABool(null);
+    foo.setANestedMessage(null);
+    foo.setARepeatedMessageList(null);
+    foo.setARepeatedStringList(null);
+    assertNull(foo.getAString());
+    assertNull(foo.getABool());
+    assertNull(foo.getANestedMessage());
+    assertObjectEquals([], foo.getARepeatedMessageList());
+    assertObjectEquals([], foo.getARepeatedStringList());
+    assertObjectEquals([null, null, null, [], []], foo.toArray());
+
+    // Test set(undefined). Again, not something we really need, and not
+    // supported directly by our typing, but it should 'do the right thing'.
+    data = ['str', true, [11], [[22], [33]], ['s1', 's2']];
+    foo = new proto.jspb.test.OptionalFields(data);
+    foo.setAString(undefined);
+    foo.setABool(undefined);
+    foo.setANestedMessage(undefined);
+    foo.setARepeatedMessageList(undefined);
+    foo.setARepeatedStringList(undefined);
+    assertUndefined(foo.getAString());
+    assertUndefined(foo.getABool());
+    assertUndefined(foo.getANestedMessage());
+    assertObjectEquals([], foo.getARepeatedMessageList());
+    assertObjectEquals([], foo.getARepeatedStringList());
+    expected = [,,, [], []];
+    expected[0] = expected[1] = expected[2] = undefined;
+    assertObjectEquals(expected, foo.toArray());
+  });
+
+  it('testDifferenceRawObject', function() {
+    var p1 = new proto.jspb.test.HasExtensions(['hi', 'diff', {}]);
+    var p2 = new proto.jspb.test.HasExtensions(['hi', 'what',
+                                               {1000: 'unique'}]);
+    var diff = /** @type {proto.jspb.test.HasExtensions} */
+        (jspb.Message.difference(p1, p2));
+    assertUndefined(diff.getStr1());
+    assertEquals('what', diff.getStr2());
+    assertUndefined(diff.getStr3());
+    assertEquals('unique', diff.extensionObject_[1000]);
+  });
+
+  it('testEqualsSimple', function() {
+    var s1 = new proto.jspb.test.Simple1(['hi']);
+    assertTrue(jspb.Message.equals(s1, new proto.jspb.test.Simple1(['hi'])));
+    assertFalse(jspb.Message.equals(s1, new proto.jspb.test.Simple1(['bye'])));
+    var s1b = new proto.jspb.test.Simple1(['hi', ['hello']]);
+    assertTrue(jspb.Message.equals(s1b,
+        new proto.jspb.test.Simple1(['hi', ['hello']])));
+    assertTrue(jspb.Message.equals(s1b,
+        new proto.jspb.test.Simple1(['hi', ['hello', undefined,
+                                            undefined, undefined]])));
+    assertFalse(jspb.Message.equals(s1b,
+        new proto.jspb.test.Simple1(['no', ['hello']])));
+    // Test with messages of different types
+    var s2 = new proto.jspb.test.Simple2(['hi']);
+    assertFalse(jspb.Message.equals(s1, s2));
+  });
+
+  it('testEquals_softComparison', function() {
+    var s1 = new proto.jspb.test.Simple1(['hi', [], null]);
+    assertTrue(jspb.Message.equals(s1,
+        new proto.jspb.test.Simple1(['hi', []])));
+
+    var s1b = new proto.jspb.test.Simple1(['hi', [], true]);
+    assertTrue(jspb.Message.equals(s1b,
+        new proto.jspb.test.Simple1(['hi', [], 1])));
+  });
+
+  it('testEqualsComplex', function() {
+    var data1 = ['a',,, [, 11], [[, 22], [, 33]],, ['s1', 's2'],, 1];
+    var data2 = ['a',,, [, 11], [[, 22], [, 34]],, ['s1', 's2'],, 1];
+    var data3 = ['a',,, [, 11], [[, 22]],, ['s1', 's2'],, 1];
+    var data4 = ['hi'];
+    var c1a = new proto.jspb.test.Complex(data1);
+    var c1b = new proto.jspb.test.Complex(data1);
+    var c2 = new proto.jspb.test.Complex(data2);
+    var c3 = new proto.jspb.test.Complex(data3);
+    var s1 = new proto.jspb.test.Simple1(data4);
+
+    assertTrue(jspb.Message.equals(c1a, c1b));
+    assertFalse(jspb.Message.equals(c1a, c2));
+    assertFalse(jspb.Message.equals(c2, c3));
+    assertFalse(jspb.Message.equals(c1a, s1));
+  });
+
+  it('testEqualsExtensionsConstructed', function() {
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions([]),
+        new proto.jspb.test.HasExtensions([{}])
+    ));
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions(['hi', {100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions(['hi', {100: [{200: 'a'}]}])
+    ));
+    assertFalse(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions(['hi', {100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions(['hi', {100: [{200: 'b'}]}])
+    ));
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions([{100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions([{100: [{200: 'a'}]}])
+    ));
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions([{100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions([,,, {100: [{200: 'a'}]}])
+    ));
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions([,,, {100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions([{100: [{200: 'a'}]}])
+    ));
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions(['hi', {100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions(['hi',,, {100: [{200: 'a'}]}])
+    ));
+    assertTrue(jspb.Message.equals(
+        new proto.jspb.test.HasExtensions(['hi',,, {100: [{200: 'a'}]}]),
+        new proto.jspb.test.HasExtensions(['hi', {100: [{200: 'a'}]}])
+    ));
+  });
+
+  it('testEqualsExtensionsUnconstructed', function() {
+    assertTrue(jspb.Message.compareFields([], [{}]));
+    assertTrue(jspb.Message.compareFields([,,, {}], []));
+    assertTrue(jspb.Message.compareFields([,,, {}], [,, {}]));
+    assertTrue(jspb.Message.compareFields(
+        ['hi', {100: [{200: 'a'}]}], ['hi', {100: [{200: 'a'}]}]));
+    assertFalse(jspb.Message.compareFields(
+        ['hi', {100: [{200: 'a'}]}], ['hi', {100: [{200: 'b'}]}]));
+    assertTrue(jspb.Message.compareFields(
+        [{100: [{200: 'a'}]}], [{100: [{200: 'a'}]}]));
+    assertTrue(jspb.Message.compareFields(
+        [{100: [{200: 'a'}]}], [,,, {100: [{200: 'a'}]}]));
+    assertTrue(jspb.Message.compareFields(
+        [,,, {100: [{200: 'a'}]}], [{100: [{200: 'a'}]}]));
+    assertTrue(jspb.Message.compareFields(
+        ['hi', {100: [{200: 'a'}]}], ['hi',,, {100: [{200: 'a'}]}]));
+    assertTrue(jspb.Message.compareFields(
+        ['hi',,, {100: [{200: 'a'}]}], ['hi', {100: [{200: 'a'}]}]));
+  });
+
+  it('testToMap', function() {
+    var p1 = new proto.jspb.test.Simple1(['k', ['v']]);
+    var p2 = new proto.jspb.test.Simple1(['k1', ['v1', 'v2']]);
+    var soymap = jspb.Message.toMap([p1, p2],
+        proto.jspb.test.Simple1.prototype.getAString,
+        proto.jspb.test.Simple1.prototype.toObject);
+    assertEquals('k', soymap['k'].aString);
+    assertArrayEquals(['v'], soymap['k'].aRepeatedStringList);
+    var protomap = jspb.Message.toMap([p1, p2],
+        proto.jspb.test.Simple1.prototype.getAString);
+    assertEquals('k', protomap['k'].getAString());
+    assertArrayEquals(['v'], protomap['k'].getARepeatedStringList());
+  });
+
+  it('testClone', function() {
+    var original = new proto.jspb.test.TestClone();
+    original.setStr('v1');
+    var simple1 = new proto.jspb.test.Simple1(['x1', ['y1', 'z1']]);
+    var simple2 = new proto.jspb.test.Simple1(['x2', ['y2', 'z2']]);
+    var simple3 = new proto.jspb.test.Simple1(['x3', ['y3', 'z3']]);
+    original.setSimple1(simple1);
+    original.setSimple2List([simple2, simple3]);
+    var extension = new proto.jspb.test.CloneExtension();
+    extension.setExt('e1');
+    original.setExtension(proto.jspb.test.IsExtension.extField, extension);
+    var clone = original.cloneMessage();
+    assertArrayEquals(['v1',, ['x1', ['y1', 'z1']],,
+      [['x2', ['y2', 'z2']], ['x3', ['y3', 'z3']]],,, { 100: [, 'e1'] }],
+        clone.toArray());
+    clone.setStr('v2');
+    var simple4 = new proto.jspb.test.Simple1(['a1', ['b1', 'c1']]);
+    var simple5 = new proto.jspb.test.Simple1(['a2', ['b2', 'c2']]);
+    var simple6 = new proto.jspb.test.Simple1(['a3', ['b3', 'c3']]);
+    clone.setSimple1(simple4);
+    clone.setSimple2List([simple5, simple6]);
+    var newExtension = new proto.jspb.test.CloneExtension();
+    newExtension.setExt('e2');
+    clone.setExtension(proto.jspb.test.CloneExtension.extField, newExtension);
+    assertArrayEquals(['v2',, ['a1', ['b1', 'c1']],,
+      [['a2', ['b2', 'c2']], ['a3', ['b3', 'c3']]],,, { 100: [, 'e2'] }],
+        clone.toArray());
+    assertArrayEquals(['v1',, ['x1', ['y1', 'z1']],,
+      [['x2', ['y2', 'z2']], ['x3', ['y3', 'z3']]],,, { 100: [, 'e1'] }],
+        original.toArray());
+  });
+
+  it('testCopyInto', function() {
+    var original = new proto.jspb.test.TestClone();
+    original.setStr('v1');
+    var dest = new proto.jspb.test.TestClone();
+    dest.setStr('override');
+    var simple1 = new proto.jspb.test.Simple1(['x1', ['y1', 'z1']]);
+    var simple2 = new proto.jspb.test.Simple1(['x2', ['y2', 'z2']]);
+    var simple3 = new proto.jspb.test.Simple1(['x3', ['y3', 'z3']]);
+    var destSimple1 = new proto.jspb.test.Simple1(['ox1', ['oy1', 'oz1']]);
+    var destSimple2 = new proto.jspb.test.Simple1(['ox2', ['oy2', 'oz2']]);
+    var destSimple3 = new proto.jspb.test.Simple1(['ox3', ['oy3', 'oz3']]);
+    original.setSimple1(simple1);
+    original.setSimple2List([simple2, simple3]);
+    dest.setSimple1(destSimple1);
+    dest.setSimple2List([destSimple2, destSimple3]);
+    var extension = new proto.jspb.test.CloneExtension();
+    extension.setExt('e1');
+    original.setExtension(proto.jspb.test.CloneExtension.extField, extension);
+
+    jspb.Message.copyInto(original, dest);
+    assertArrayEquals(original.toArray(), dest.toArray());
+    assertEquals('x1', dest.getSimple1().getAString());
+    assertEquals('e1',
+        dest.getExtension(proto.jspb.test.CloneExtension.extField).getExt());
+    dest.getSimple1().setAString('new value');
+    assertNotEquals(dest.getSimple1().getAString(),
+        original.getSimple1().getAString());
+    dest.getExtension(proto.jspb.test.CloneExtension.extField).
+        setExt('new value');
+    assertNotEquals(
+        dest.getExtension(proto.jspb.test.CloneExtension.extField).getExt(),
+        original.getExtension(
+            proto.jspb.test.CloneExtension.extField).getExt());
+  });
+
+  it('testCopyInto_notSameType', function() {
+    var a = new proto.jspb.test.TestClone();
+    var b = new proto.jspb.test.Simple1(['str', ['s1', 's2']]);
+
+    var e = assertThrows(function() {
+      jspb.Message.copyInto(a, b);
+    });
+    assertContains('should have the same type', e.message);
+  });
+
+  it('testExtensions', function() {
+    var extension1 = new proto.jspb.test.IsExtension(['ext1field']);
+    var extension2 = new proto.jspb.test.Simple1(['str', ['s1', 's2']]);
+    var extendable = new proto.jspb.test.HasExtensions(['v1', 'v2', 'v3']);
+    extendable.setExtension(proto.jspb.test.IsExtension.extField, extension1);
+    extendable.setExtension(proto.jspb.test.IndirectExtension.simple,
+                            extension2);
+    extendable.setExtension(proto.jspb.test.IndirectExtension.str, 'xyzzy');
+    extendable.setExtension(proto.jspb.test.IndirectExtension.repeatedStrList,
+        ['a', 'b']);
+    var s1 = new proto.jspb.test.Simple1(['foo', ['s1', 's2']]);
+    var s2 = new proto.jspb.test.Simple1(['bar', ['t1', 't2']]);
+    extendable.setExtension(
+        proto.jspb.test.IndirectExtension.repeatedSimpleList,
+        [s1, s2]);
+    assertObjectEquals(extension1,
+        extendable.getExtension(proto.jspb.test.IsExtension.extField));
+    assertObjectEquals(extension2,
+        extendable.getExtension(proto.jspb.test.IndirectExtension.simple));
+    assertObjectEquals('xyzzy',
+        extendable.getExtension(proto.jspb.test.IndirectExtension.str));
+    assertObjectEquals(['a', 'b'], extendable.getExtension(
+        proto.jspb.test.IndirectExtension.repeatedStrList));
+    assertObjectEquals([s1, s2], extendable.getExtension(
+        proto.jspb.test.IndirectExtension.repeatedSimpleList));
+    // Not supported yet, but it should work...
+    extendable.setExtension(proto.jspb.test.IndirectExtension.simple, null);
+    assertNull(
+        extendable.getExtension(proto.jspb.test.IndirectExtension.simple));
+    extendable.setExtension(proto.jspb.test.IndirectExtension.str, null);
+    assertNull(extendable.getExtension(proto.jspb.test.IndirectExtension.str));
+
+    // These assertions will only work properly in uncompiled mode.
+    // Extension fields defined on proto2 Descriptor messages are filtered out.
+
+    // TODO(haberman): codegen changes to properly ignore descriptor.proto
+    // extensions need to be merged from google3.
+    // assertUndefined(proto.jspb.test.IsExtension['simpleOption']);
+
+    // Extension fields with jspb.ignore = true are ignored.
+    assertUndefined(proto.jspb.test.IndirectExtension['ignored']);
+    assertUndefined(proto.jspb.test.HasExtensions['ignoredFloating']);
+  });
+
+  it('testFloatingExtensions', function() {
+    // From an autogenerated container.
+    var extendable = new proto.jspb.test.HasExtensions(['v1', 'v2', 'v3']);
+    var extension = new proto.jspb.test.Simple1(['foo', ['s1', 's2']]);
+    extendable.setExtension(proto.jspb.test.simple1, extension);
+    assertObjectEquals(extension,
+        extendable.getExtension(proto.jspb.test.simple1));
+
+    // From _lib mode.
+    extension = new proto.jspb.test.ExtensionMessage(['s1']);
+    extendable = new proto.jspb.test.TestExtensionsMessage([16]);
+    extendable.setExtension(proto.jspb.test.floatingMsgField, extension);
+    extendable.setExtension(proto.jspb.test.floatingStrField, 's2');
+    assertObjectEquals(extension,
+        extendable.getExtension(proto.jspb.test.floatingMsgField));
+    assertObjectEquals('s2',
+        extendable.getExtension(proto.jspb.test.floatingStrField));
+    assertNotUndefined(proto.jspb.exttest.floatingMsgField);
+    assertNotUndefined(proto.jspb.exttest.floatingMsgFieldTwo);
+    assertNotUndefined(proto.jspb.exttest.beta.floatingStrField);
+  });
+
+  it('testToObject_extendedObject', function() {
+    var extension1 = new proto.jspb.test.IsExtension(['ext1field']);
+    var extension2 = new proto.jspb.test.Simple1(['str', ['s1', 's2'], true]);
+    var extendable = new proto.jspb.test.HasExtensions(['v1', 'v2', 'v3']);
+    extendable.setExtension(proto.jspb.test.IsExtension.extField, extension1);
+    extendable.setExtension(proto.jspb.test.IndirectExtension.simple,
+                            extension2);
+    extendable.setExtension(proto.jspb.test.IndirectExtension.str, 'xyzzy');
+    extendable.setExtension(proto.jspb.test.IndirectExtension.repeatedStrList,
+        ['a', 'b']);
+    var s1 = new proto.jspb.test.Simple1(['foo', ['s1', 's2'], true]);
+    var s2 = new proto.jspb.test.Simple1(['bar', ['t1', 't2'], false]);
+    extendable.setExtension(
+        proto.jspb.test.IndirectExtension.repeatedSimpleList,
+        [s1, s2]);
+    assertObjectEquals({
+      str1: 'v1', str2: 'v2', str3: 'v3',
+      extField: { ext1: 'ext1field' },
+      simple: {
+        aString: 'str', aRepeatedStringList: ['s1', 's2'], aBoolean: true
+      },
+      str: 'xyzzy',
+      repeatedStrList: ['a', 'b'],
+      repeatedSimpleList: [
+        { aString: 'foo', aRepeatedStringList: ['s1', 's2'], aBoolean: true},
+        { aString: 'bar', aRepeatedStringList: ['t1', 't2'], aBoolean: false}
+      ]
+    }, extendable.toObject());
+
+    // Now, with instances included.
+    assertObjectEquals({
+      str1: 'v1', str2: 'v2', str3: 'v3',
+      extField: {
+        ext1: 'ext1field',
+        $jspbMessageInstance:
+            extendable.getExtension(proto.jspb.test.IsExtension.extField)
+      },
+      simple: {
+        aString: 'str',
+        aRepeatedStringList: ['s1', 's2'],
+        aBoolean: true,
+        $jspbMessageInstance:
+            extendable.getExtension(proto.jspb.test.IndirectExtension.simple)
+      },
+      str: 'xyzzy',
+      repeatedStrList: ['a', 'b'],
+      repeatedSimpleList: [{
+        aString: 'foo',
+        aRepeatedStringList: ['s1', 's2'],
+        aBoolean: true,
+        $jspbMessageInstance: s1
+      }, {
+        aString: 'bar',
+        aRepeatedStringList: ['t1', 't2'],
+        aBoolean: false,
+        $jspbMessageInstance: s2
+      }],
+      $jspbMessageInstance: extendable
+    }, extendable.toObject(true /* opt_includeInstance */));
+  });
+
+  it('testInitialization_emptyArray', function() {
+    var msg = new proto.jspb.test.HasExtensions([]);
+    if (jspb.Message.MINIMIZE_MEMORY_ALLOCATIONS) {
+      assertArrayEquals([], msg.toArray());
+    } else {
+      // Extension object is created past all regular fields.
+      assertArrayEquals([,,, {}], msg.toArray());
+    }
+  });
+
+  it('testInitialization_justExtensionObject', function() {
+    var msg = new proto.jspb.test.Empty([{1: 'hi'}]);
+    // The extensionObject is not moved from its original location.
+    assertArrayEquals([{1: 'hi'}], msg.toArray());
+  });
+
+  it('testInitialization_incompleteList', function() {
+    var msg = new proto.jspb.test.Empty([1, {4: 'hi'}]);
+    // The extensionObject is not moved from its original location.
+    assertArrayEquals([1, {4: 'hi'}], msg.toArray());
+  });
+
+  it('testInitialization_forwardCompatible', function() {
+    var msg = new proto.jspb.test.Empty([1, 2, 3, {1: 'hi'}]);
+    assertArrayEquals([1, 2, 3, {1: 'hi'}], msg.toArray());
+  });
+
+  it('testExtendedMessageEnsureObject', function() {
+    var data = new proto.jspb.test.HasExtensions(['str1',
+        {'a_key': 'an_object'}]);
+    assertEquals('an_object', data.extensionObject_['a_key']);
+  });
+
+  it('testToObject_hasExtensionField', function() {
+    var data = new proto.jspb.test.HasExtensions(['str1', {100: ['ext1']}]);
+    var obj = data.toObject();
+    assertEquals('str1', obj.str1);
+    assertEquals('ext1', obj.extField.ext1);
+  });
+
+  it('testGetExtension', function() {
+    var data = new proto.jspb.test.HasExtensions(['str1', {100: ['ext1']}]);
+    assertEquals('str1', data.getStr1());
+    var extension = data.getExtension(proto.jspb.test.IsExtension.extField);
+    assertNotNull(extension);
+    assertEquals('ext1', extension.getExt1());
+  });
+
+  it('testSetExtension', function() {
+    var data = new proto.jspb.test.HasExtensions();
+    var extensionMessage = new proto.jspb.test.IsExtension(['is_extension']);
+    data.setExtension(proto.jspb.test.IsExtension.extField, extensionMessage);
+    var obj = data.toObject();
+    assertNotNull(
+        data.getExtension(proto.jspb.test.IsExtension.extField));
+    assertEquals('is_extension', obj.extField.ext1);
+  });
+
+  /**
+   * Note that group is long deprecated, we only support it because JsPb has
+   * a goal of being able to generate JS classes for all proto descriptors.
+   */
+  it('testGroups', function() {
+    var group = new proto.jspb.test.TestGroup();
+    var someGroup = new proto.jspb.test.TestGroup.RepeatedGroup();
+    someGroup.setId('g1');
+    someGroup.setSomeBoolList([true, false]);
+    group.setRepeatedGroupList([someGroup]);
+    var groups = group.getRepeatedGroupList();
+    assertEquals('g1', groups[0].getId());
+    assertObjectEquals([true, false], groups[0].getSomeBoolList());
+    assertObjectEquals({id: 'g1', someBoolList: [true, false]},
+        groups[0].toObject());
+    assertObjectEquals({
+      repeatedGroupList: [{id: 'g1', someBoolList: [true, false]}],
+      requiredGroup: {id: undefined},
+      optionalGroup: undefined,
+      requiredSimple: {aRepeatedStringList: [], aString: undefined},
+      optionalSimple: undefined,
+      id: undefined
+    }, group.toObject());
+    var group1 = new proto.jspb.test.TestGroup1();
+    group1.setGroup(someGroup);
+    assertEquals(someGroup, group1.getGroup());
+  });
+
+  it('testNonExtensionFieldsAfterExtensionRange', function() {
+    var data = [{'1': 'a_string'}];
+    var message = new proto.jspb.test.Complex(data);
+    assertArrayEquals([], message.getARepeatedStringList());
+  });
+
+  it('testReservedGetterNames', function() {
+    var message = new proto.jspb.test.TestReservedNames();
+    message.setExtension$(11);
+    message.setExtension(proto.jspb.test.TestReservedNamesExtension.foo, 12);
+    assertEquals(11, message.getExtension$());
+    assertEquals(12, message.getExtension(
+        proto.jspb.test.TestReservedNamesExtension.foo));
+    assertObjectEquals({extension: 11, foo: 12}, message.toObject());
+  });
+
+  it('testInitializeMessageWithUnsetOneof', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof([]);
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.
+            PARTIAL_ONEOF_NOT_SET,
+        message.getPartialOneofCase());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.RecursiveOneofCase.
+            RECURSIVE_ONEOF_NOT_SET,
+        message.getRecursiveOneofCase());
+  });
+
+  it('testInitializeMessageWithSingleValueSetInOneof', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof([,, 'x']);
+
+    assertEquals('x', message.getPone());
+    assertUndefined(message.getPthree());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.PONE,
+        message.getPartialOneofCase());
+  });
+
+  it('testKeepsLastWireValueSetInUnion_multipleValues', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof([,, 'x',, 'y']);
+
+    assertUndefined('x', message.getPone());
+    assertEquals('y', message.getPthree());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.PTHREE,
+        message.getPartialOneofCase());
+  });
+
+  it('testSettingOneofFieldClearsOthers', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    assertUndefined(message.getPone());
+    assertUndefined(message.getPthree());
+
+    message.setPone('hi');
+    assertEquals('hi', message.getPone());
+    assertUndefined(message.getPthree());
+
+    message.setPthree('bye');
+    assertUndefined(message.getPone());
+    assertEquals('bye', message.getPthree());
+  });
+
+  it('testSettingOneofFieldDoesNotClearFieldsFromOtherUnions', function() {
+    var other = new proto.jspb.test.TestMessageWithOneof;
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    assertUndefined(message.getPone());
+    assertUndefined(message.getPthree());
+    assertUndefined(message.getRone());
+
+    message.setPone('hi');
+    message.setRone(other);
+    assertEquals('hi', message.getPone());
+    assertUndefined(message.getPthree());
+    assertEquals(other, message.getRone());
+
+    message.setPthree('bye');
+    assertUndefined(message.getPone());
+    assertEquals('bye', message.getPthree());
+    assertEquals(other, message.getRone());
+  });
+
+  it('testUnsetsOneofCaseWhenFieldIsCleared', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.
+            PARTIAL_ONEOF_NOT_SET,
+        message.getPartialOneofCase());
+
+    message.setPone('hi');
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.PONE,
+        message.getPartialOneofCase());
+
+    message.clearPone();
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.
+            PARTIAL_ONEOF_NOT_SET,
+        message.getPartialOneofCase());
+  });
+
+  it('testMessageWithDefaultOneofValues', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    assertEquals(1234, message.getAone());
+    assertUndefined(message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase
+            .DEFAULT_ONEOF_A_NOT_SET,
+        message.getDefaultOneofACase());
+
+    message.setAone(567);
+    assertEquals(567, message.getAone());
+    assertUndefined(message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase.AONE,
+        message.getDefaultOneofACase());
+
+    message.setAtwo(890);
+    assertEquals(1234, message.getAone());
+    assertEquals(890, message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase.ATWO,
+        message.getDefaultOneofACase());
+
+    message.clearAtwo();
+    assertEquals(1234, message.getAone());
+    assertUndefined(message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase
+            .DEFAULT_ONEOF_A_NOT_SET,
+        message.getDefaultOneofACase());
+  });
+
+  it('testMessageWithDefaultOneofValues_defaultNotOnFirstField', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    assertUndefined(message.getBone());
+    assertEquals(1234, message.getBtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase
+            .DEFAULT_ONEOF_B_NOT_SET,
+        message.getDefaultOneofBCase());
+
+    message.setBone(2);
+    assertEquals(2, message.getBone());
+    assertEquals(1234, message.getBtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase.BONE,
+        message.getDefaultOneofBCase());
+
+    message.setBtwo(3);
+    assertUndefined(message.getBone());
+    assertEquals(3, message.getBtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase.BTWO,
+        message.getDefaultOneofBCase());
+
+    message.clearBtwo();
+    assertUndefined(message.getBone());
+    assertEquals(1234, message.getBtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase
+            .DEFAULT_ONEOF_B_NOT_SET,
+        message.getDefaultOneofBCase());
+  });
+
+  it('testInitializeMessageWithOneofDefaults', function() {
+    var message =
+        new proto.jspb.test.TestMessageWithOneof(new Array(9).concat(567));
+    assertEquals(567, message.getAone());
+    assertUndefined(message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase.AONE,
+        message.getDefaultOneofACase());
+
+    message =
+        new proto.jspb.test.TestMessageWithOneof(new Array(10).concat(890));
+    assertEquals(1234, message.getAone());
+    assertEquals(890, message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase.ATWO,
+        message.getDefaultOneofACase());
+
+    message =
+        new proto.jspb.test.TestMessageWithOneof(new Array(9).concat(567,890));
+    assertEquals(1234, message.getAone());
+    assertEquals(890, message.getAtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.DefaultOneofACase.ATWO,
+        message.getDefaultOneofACase());
+  });
+
+  it('testInitializeMessageWithOneofDefaults_defaultNotSetOnFirstField',
+      function() {
+        var message;
+
+        message =
+            new proto.jspb.test.TestMessageWithOneof(new Array(11).concat(567));
+        assertEquals(567, message.getBone());
+        assertEquals(1234, message.getBtwo());
+        assertEquals(
+            proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase.BONE,
+            message.getDefaultOneofBCase());
+
+        message =
+            new proto.jspb.test.TestMessageWithOneof(new Array(12).concat(890));
+        assertUndefined(message.getBone());
+        assertEquals(890, message.getBtwo());
+        assertEquals(
+            proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase.BTWO,
+            message.getDefaultOneofBCase());
+
+        message = new proto.jspb.test.TestMessageWithOneof(
+            new Array(11).concat(567,890));
+        assertUndefined(message.getBone());
+        assertEquals(890, message.getBtwo());
+        assertEquals(
+            proto.jspb.test.TestMessageWithOneof.DefaultOneofBCase.BTWO,
+            message.getDefaultOneofBCase());
+      });
+
+  it('testOneofContainingAnotherMessage', function() {
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.RecursiveOneofCase.
+            RECURSIVE_ONEOF_NOT_SET,
+        message.getRecursiveOneofCase());
+
+    var other = new proto.jspb.test.TestMessageWithOneof;
+    message.setRone(other);
+    assertEquals(other, message.getRone());
+    assertUndefined(message.getRtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.RecursiveOneofCase.RONE,
+        message.getRecursiveOneofCase());
+
+    message.setRtwo('hi');
+    assertUndefined(message.getRone());
+    assertEquals('hi', message.getRtwo());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.RecursiveOneofCase.RTWO,
+        message.getRecursiveOneofCase());
+  });
+
+  it('testQueryingOneofCaseEnsuresOnlyOneFieldIsSetInUnderlyingArray',
+     function() {
+    var message = new proto.jspb.test.TestMessageWithOneof;
+    message.setPone('x');
+    assertEquals('x', message.getPone());
+    assertUndefined(message.getPthree());
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.PONE,
+        message.getPartialOneofCase());
+
+    var array = message.toArray();
+    assertEquals('x', array[2]);
+    assertUndefined(array[4]);
+    array[4] = 'y';
+
+    assertEquals(
+        proto.jspb.test.TestMessageWithOneof.PartialOneofCase.PTHREE,
+        message.getPartialOneofCase());
+    assertUndefined(array[2]);
+    assertEquals('y', array[4]);
+  });
+
+});