Update //third_party/protobuf to version 3.

third_party/protobuf/objectivec/Tests/GPBMessageTests.m

+// 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.
+
+#import "GPBTestUtilities.h"
+
+#import <objc/runtime.h>
+
+#import "GPBArray_PackagePrivate.h"
+#import "GPBDescriptor.h"
+#import "GPBDictionary_PackagePrivate.h"
+#import "GPBMessage_PackagePrivate.h"
+#import "GPBUnknownField_PackagePrivate.h"
+#import "GPBUnknownFieldSet_PackagePrivate.h"
+#import "google/protobuf/Unittest.pbobjc.h"
+#import "google/protobuf/UnittestObjc.pbobjc.h"
+
+@interface MessageTests : GPBTestCase
+@end
+
+@implementation MessageTests
+
+// TODO(thomasvl): this should get split into a few files of logic junks, it is
+// a jumble of things at the moment (and the testutils have a bunch of the real
+// assertions).
+
+- (TestAllTypes *)mergeSource {
+  TestAllTypes *message = [TestAllTypes message];
+  [message setOptionalInt32:1];
+  [message setOptionalString:@"foo"];
+  [message setOptionalForeignMessage:[ForeignMessage message]];
+  message.repeatedStringArray = [NSMutableArray array];
+  [message.repeatedStringArray addObject:@"bar"];
+  return message;
+}
+
+- (TestAllTypes *)mergeDestination {
+  TestAllTypes *message = [TestAllTypes message];
+  [message setOptionalInt64:2];
+  [message setOptionalString:@"baz"];
+  ForeignMessage *foreignMessage = [ForeignMessage message];
+  [foreignMessage setC:3];
+  [message setOptionalForeignMessage:foreignMessage];
+  message.repeatedStringArray = [NSMutableArray array];
+  [message.repeatedStringArray addObject:@"qux"];
+  return message;
+}
+
+- (TestAllTypes *)mergeDestinationWithoutForeignMessageIvar {
+  TestAllTypes *message = [TestAllTypes message];
+  [message setOptionalInt64:2];
+  [message setOptionalString:@"baz"];
+  message.repeatedStringArray = [NSMutableArray array];
+  [message.repeatedStringArray addObject:@"qux"];
+  return message;
+}
+
+- (TestAllTypes *)mergeResult {
+  TestAllTypes *message = [TestAllTypes message];
+  [message setOptionalInt32:1];
+  [message setOptionalInt64:2];
+  [message setOptionalString:@"foo"];
+  ForeignMessage *foreignMessage = [ForeignMessage message];
+  [foreignMessage setC:3];
+  [message setOptionalForeignMessage:foreignMessage];
+  message.repeatedStringArray = [NSMutableArray array];
+  [message.repeatedStringArray addObject:@"qux"];
+  [message.repeatedStringArray addObject:@"bar"];
+  return message;
+}
+
+- (TestAllTypes *)mergeResultForDestinationWithoutForeignMessageIvar {
+  TestAllTypes *message = [TestAllTypes message];
+  [message setOptionalInt32:1];
+  [message setOptionalInt64:2];
+  [message setOptionalString:@"foo"];
+  ForeignMessage *foreignMessage = [ForeignMessage message];
+  [message setOptionalForeignMessage:foreignMessage];
+  message.repeatedStringArray = [NSMutableArray array];
+  [message.repeatedStringArray addObject:@"qux"];
+  [message.repeatedStringArray addObject:@"bar"];
+  return message;
+}
+
+- (TestAllExtensions *)mergeExtensionsDestination {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [message setExtension:[UnittestRoot optionalInt32Extension] value:@5];
+  [message setExtension:[UnittestRoot optionalStringExtension] value:@"foo"];
+  ForeignMessage *foreignMessage = [ForeignMessage message];
+  foreignMessage.c = 4;
+  [message setExtension:[UnittestRoot optionalForeignMessageExtension]
+                  value:foreignMessage];
+  TestAllTypes_NestedMessage *nestedMessage =
+      [TestAllTypes_NestedMessage message];
+  [message setExtension:[UnittestRoot optionalNestedMessageExtension]
+                  value:nestedMessage];
+  return message;
+}
+
+- (TestAllExtensions *)mergeExtensionsSource {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [message setExtension:[UnittestRoot optionalInt64Extension] value:@6];
+  [message setExtension:[UnittestRoot optionalStringExtension] value:@"bar"];
+  ForeignMessage *foreignMessage = [ForeignMessage message];
+  [message setExtension:[UnittestRoot optionalForeignMessageExtension]
+                  value:foreignMessage];
+  TestAllTypes_NestedMessage *nestedMessage =
+      [TestAllTypes_NestedMessage message];
+  nestedMessage.bb = 7;
+  [message setExtension:[UnittestRoot optionalNestedMessageExtension]
+                  value:nestedMessage];
+  return message;
+}
+
+- (TestAllExtensions *)mergeExtensionsResult {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [message setExtension:[UnittestRoot optionalInt32Extension] value:@5];
+  [message setExtension:[UnittestRoot optionalInt64Extension] value:@6];
+  [message setExtension:[UnittestRoot optionalStringExtension] value:@"bar"];
+  ForeignMessage *foreignMessage = [ForeignMessage message];
+  foreignMessage.c = 4;
+  [message setExtension:[UnittestRoot optionalForeignMessageExtension]
+                  value:foreignMessage];
+  TestAllTypes_NestedMessage *nestedMessage =
+      [TestAllTypes_NestedMessage message];
+  nestedMessage.bb = 7;
+  [message setExtension:[UnittestRoot optionalNestedMessageExtension]
+                  value:nestedMessage];
+  return message;
+}
+
+- (void)testMergeFrom {
+  TestAllTypes *result = [[self.mergeDestination copy] autorelease];
+  [result mergeFrom:self.mergeSource];
+  NSData *resultData = [result data];
+  NSData *mergeResultData = [self.mergeResult data];
+  XCTAssertEqualObjects(resultData, mergeResultData);
+  XCTAssertEqualObjects(result, self.mergeResult);
+
+  // Test when destination does not have an Ivar (type is an object) but source
+  // has such Ivar.
+  // The result must has the Ivar which is same as the one in source.
+  result = [[self.mergeDestinationWithoutForeignMessageIvar copy] autorelease];
+  [result mergeFrom:self.mergeSource];
+  resultData = [result data];
+  mergeResultData =
+      [self.mergeResultForDestinationWithoutForeignMessageIvar data];
+  XCTAssertEqualObjects(resultData, mergeResultData);
+  XCTAssertEqualObjects(
+      result, self.mergeResultForDestinationWithoutForeignMessageIvar);
+
+  // Test when destination is empty.
+  // The result must is same as the source.
+  result = [TestAllTypes message];
+  [result mergeFrom:self.mergeSource];
+  resultData = [result data];
+  mergeResultData = [self.mergeSource data];
+  XCTAssertEqualObjects(resultData, mergeResultData);
+  XCTAssertEqualObjects(result, self.mergeSource);
+}
+
+- (void)testMergeFromWithExtensions {
+  TestAllExtensions *result = [self mergeExtensionsDestination];
+  [result mergeFrom:[self mergeExtensionsSource]];
+  NSData *resultData = [result data];
+  NSData *mergeResultData = [[self mergeExtensionsResult] data];
+  XCTAssertEqualObjects(resultData, mergeResultData);
+  XCTAssertEqualObjects(result, [self mergeExtensionsResult]);
+
+  // Test merging from data.
+  result = [self mergeExtensionsDestination];
+  NSData *data = [[self mergeExtensionsSource] data];
+  XCTAssertNotNil(data);
+  [result mergeFromData:data
+      extensionRegistry:[UnittestRoot extensionRegistry]];
+  resultData = [result data];
+  XCTAssertEqualObjects(resultData, mergeResultData);
+  XCTAssertEqualObjects(result, [self mergeExtensionsResult]);
+}
+
+- (void)testIsEquals {
+  TestAllTypes *result = [[self.mergeDestination copy] autorelease];
+  [result mergeFrom:self.mergeSource];
+  XCTAssertEqualObjects(result.data, self.mergeResult.data);
+  XCTAssertEqualObjects(result, self.mergeResult);
+  TestAllTypes *result2 = [[self.mergeDestination copy] autorelease];
+  XCTAssertNotEqualObjects(result2.data, self.mergeResult.data);
+  XCTAssertNotEqualObjects(result2, self.mergeResult);
+}
+
+// =================================================================
+// Required-field-related tests.
+
+- (TestRequired *)testRequiredInitialized {
+  TestRequired *message = [TestRequired message];
+  [message setA:1];
+  [message setB:2];
+  [message setC:3];
+  return message;
+}
+
+- (void)testRequired {
+  TestRequired *message = [TestRequired message];
+
+  XCTAssertFalse(message.initialized);
+  [message setA:1];
+  XCTAssertFalse(message.initialized);
+  [message setB:1];
+  XCTAssertFalse(message.initialized);
+  [message setC:1];
+  XCTAssertTrue(message.initialized);
+}
+
+- (void)testRequiredForeign {
+  TestRequiredForeign *message = [TestRequiredForeign message];
+
+  XCTAssertTrue(message.initialized);
+
+  [message setOptionalMessage:[TestRequired message]];
+  XCTAssertFalse(message.initialized);
+
+  [message setOptionalMessage:self.testRequiredInitialized];
+  XCTAssertTrue(message.initialized);
+
+  message.repeatedMessageArray = [NSMutableArray array];
+  [message.repeatedMessageArray addObject:[TestRequired message]];
+  XCTAssertFalse(message.initialized);
+
+  [message.repeatedMessageArray removeAllObjects];
+  [message.repeatedMessageArray addObject:self.testRequiredInitialized];
+  XCTAssertTrue(message.initialized);
+}
+
+- (void)testRequiredExtension {
+  TestAllExtensions *message = [TestAllExtensions message];
+
+  XCTAssertTrue(message.initialized);
+
+  [message setExtension:[TestRequired single] value:[TestRequired message]];
+  XCTAssertFalse(message.initialized);
+
+  [message setExtension:[TestRequired single]
+                  value:self.testRequiredInitialized];
+  XCTAssertTrue(message.initialized);
+
+  [message addExtension:[TestRequired multi] value:[TestRequired message]];
+  XCTAssertFalse(message.initialized);
+
+  [message setExtension:[TestRequired multi]
+                  index:0
+                  value:self.testRequiredInitialized];
+  XCTAssertTrue(message.initialized);
+}
+
+- (void)testDataFromUninitialized {
+  TestRequired *message = [TestRequired message];
+  NSData *data = [message data];
+  // In DEBUG, the data generation will fail, but in non DEBUG, it passes
+  // because the check isn't done (for speed).
+#ifdef DEBUG
+  XCTAssertNil(data);
+#else
+  XCTAssertNotNil(data);
+  XCTAssertFalse(message.initialized);
+#endif  // DEBUG
+}
+
+- (void)testInitialized {
+  // We're mostly testing that no exception is thrown.
+  TestRequired *message = [TestRequired message];
+  XCTAssertFalse(message.initialized);
+}
+
+- (void)testDataFromNestedUninitialized {
+  TestRequiredForeign *message = [TestRequiredForeign message];
+  [message setOptionalMessage:[TestRequired message]];
+  message.repeatedMessageArray = [NSMutableArray array];
+  [message.repeatedMessageArray addObject:[TestRequired message]];
+  [message.repeatedMessageArray addObject:[TestRequired message]];
+  NSData *data = [message data];
+  // In DEBUG, the data generation will fail, but in non DEBUG, it passes
+  // because the check isn't done (for speed).
+#ifdef DEBUG
+  XCTAssertNil(data);
+#else
+  XCTAssertNotNil(data);
+  XCTAssertFalse(message.initialized);
+#endif  // DEBUG
+}
+
+- (void)testNestedInitialized {
+  // We're mostly testing that no exception is thrown.
+
+  TestRequiredForeign *message = [TestRequiredForeign message];
+  [message setOptionalMessage:[TestRequired message]];
+  message.repeatedMessageArray = [NSMutableArray array];
+  [message.repeatedMessageArray addObject:[TestRequired message]];
+  [message.repeatedMessageArray addObject:[TestRequired message]];
+
+  XCTAssertFalse(message.initialized);
+}
+
+- (void)testParseUninitialized {
+  NSError *error = nil;
+  TestRequired *msg =
+      [TestRequired parseFromData:GPBEmptyNSData() error:&error];
+  // In DEBUG, the parse will fail, but in non DEBUG, it passes because
+  // the check isn't done (for speed).
+#ifdef DEBUG
+  XCTAssertNil(msg);
+  XCTAssertNotNil(error);
+  XCTAssertEqualObjects(error.domain, GPBMessageErrorDomain);
+  XCTAssertEqual(error.code, GPBMessageErrorCodeMissingRequiredField);
+#else
+  XCTAssertNotNil(msg);
+  XCTAssertNil(error);
+  XCTAssertFalse(msg.initialized);
+#endif  // DEBUG
+}
+
+- (void)testCoding {
+  NSData *data =
+      [NSKeyedArchiver archivedDataWithRootObject:[self mergeResult]];
+  id unarchivedObject = [NSKeyedUnarchiver unarchiveObjectWithData:data];
+
+  XCTAssertEqualObjects(unarchivedObject, [self mergeResult]);
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(unarchivedObject, [self mergeResult]);
+}
+
+- (void)testObjectReset {
+  // Tests a failure where clearing out defaults values caused an over release.
+  TestAllTypes *message = [TestAllTypes message];
+  message.hasOptionalNestedMessage = NO;
+  [message setOptionalNestedMessage:[TestAllTypes_NestedMessage message]];
+  message.hasOptionalNestedMessage = NO;
+  [message setOptionalNestedMessage:[TestAllTypes_NestedMessage message]];
+  [message setOptionalNestedMessage:nil];
+  message.hasOptionalNestedMessage = NO;
+}
+
+- (void)testSettingHasToYes {
+  TestAllTypes *message = [TestAllTypes message];
+  XCTAssertThrows([message setHasOptionalNestedMessage:YES]);
+}
+
+- (void)testRoot {
+  XCTAssertNotNil([UnittestRoot extensionRegistry]);
+}
+
+- (void)testGPBMessageSize {
+  // See the note in GPBMessage_PackagePrivate.h about why we want to keep the
+  // base instance size pointer size aligned.
+  size_t messageSize = class_getInstanceSize([GPBMessage class]);
+  XCTAssertEqual((messageSize % sizeof(void *)), (size_t)0,
+                 @"Base size isn't pointer size aligned");
+
+  // Since we add storage ourselves (see +allocWithZone: in GPBMessage), confirm
+  // that the size of some generated classes is still the same as the base for
+  // that logic to work as desired.
+  size_t testMessageSize = class_getInstanceSize([TestAllTypes class]);
+  XCTAssertEqual(testMessageSize, messageSize);
+}
+
+- (void)testInit {
+  TestAllTypes *message = [TestAllTypes message];
+  [self assertClear:message];
+}
+
+- (void)testAccessors {
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFields:message repeatedCount:kGPBDefaultRepeatCount];
+  [self assertAllFieldsSet:message repeatedCount:kGPBDefaultRepeatCount];
+}
+
+- (void)testKVC_ValueForKey {
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFields:message repeatedCount:kGPBDefaultRepeatCount];
+  [self assertAllFieldsKVCMatch:message];
+}
+
+- (void)testKVC_SetValue_ForKey {
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFieldsViaKVC:message repeatedCount:kGPBDefaultRepeatCount];
+  [self assertAllFieldsKVCMatch:message];
+  [self assertAllFieldsSet:message repeatedCount:kGPBDefaultRepeatCount];
+  [self assertAllFieldsKVCMatch:message];
+}
+
+- (void)testDescription {
+  // No real test, just exercise code
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFields:message repeatedCount:kGPBDefaultRepeatCount];
+
+  GPBUnknownFieldSet *unknownFields =
+      [[[GPBUnknownFieldSet alloc] init] autorelease];
+  GPBUnknownField *field =
+      [[[GPBUnknownField alloc] initWithNumber:2] autorelease];
+  [field addVarint:2];
+  [unknownFields addField:field];
+  field = [[[GPBUnknownField alloc] initWithNumber:3] autorelease];
+  [field addVarint:4];
+  [unknownFields addField:field];
+
+  [message setUnknownFields:unknownFields];
+
+  NSString *description = [message description];
+  XCTAssertGreaterThan([description length], 0U);
+
+  GPBMessage *message2 = [TestAllExtensions message];
+  [message2 setExtension:[UnittestRoot optionalInt32Extension] value:@1];
+
+  [message2 addExtension:[UnittestRoot repeatedInt32Extension] value:@2];
+
+  description = [message2 description];
+  XCTAssertGreaterThan([description length], 0U);
+}
+
+- (void)testSetter {
+  // Test to make sure that if we set a value that has a default value
+  // with the default, that the has is set, and the value gets put into the
+  // message correctly.
+  TestAllTypes *message = [TestAllTypes message];
+  GPBDescriptor *descriptor = [[message class] descriptor];
+  XCTAssertNotNil(descriptor);
+  GPBFieldDescriptor *fieldDescriptor =
+      [descriptor fieldWithName:@"defaultInt32"];
+  XCTAssertNotNil(fieldDescriptor);
+  GPBGenericValue defaultValue = [fieldDescriptor defaultValue];
+  [message setDefaultInt32:defaultValue.valueInt32];
+  XCTAssertTrue(message.hasDefaultInt32);
+  XCTAssertEqual(message.defaultInt32, defaultValue.valueInt32);
+
+  // Do the same thing with an object type.
+  message = [TestAllTypes message];
+  fieldDescriptor = [descriptor fieldWithName:@"defaultString"];
+  XCTAssertNotNil(fieldDescriptor);
+  defaultValue = [fieldDescriptor defaultValue];
+  [message setDefaultString:defaultValue.valueString];
+  XCTAssertTrue(message.hasDefaultString);
+  XCTAssertEqualObjects(message.defaultString, defaultValue.valueString);
+
+  // Test default string type.
+  message = [TestAllTypes message];
+  XCTAssertEqualObjects(message.defaultString, @"hello");
+  XCTAssertFalse(message.hasDefaultString);
+  fieldDescriptor = [descriptor fieldWithName:@"defaultString"];
+  XCTAssertNotNil(fieldDescriptor);
+  defaultValue = [fieldDescriptor defaultValue];
+  [message setDefaultString:defaultValue.valueString];
+  XCTAssertEqualObjects(message.defaultString, @"hello");
+  XCTAssertTrue(message.hasDefaultString);
+  [message setDefaultString:nil];
+  XCTAssertEqualObjects(message.defaultString, @"hello");
+  XCTAssertFalse(message.hasDefaultString);
+  message.hasDefaultString = NO;
+  XCTAssertFalse(message.hasDefaultString);
+  XCTAssertEqualObjects(message.defaultString, @"hello");
+
+  // Test default bytes type.
+  NSData *defaultBytes = [@"world" dataUsingEncoding:NSUTF8StringEncoding];
+  XCTAssertEqualObjects(message.defaultBytes, defaultBytes);
+  XCTAssertFalse(message.hasDefaultString);
+  fieldDescriptor = [descriptor fieldWithName:@"defaultBytes"];
+  XCTAssertNotNil(fieldDescriptor);
+  defaultValue = [fieldDescriptor defaultValue];
+  [message setDefaultBytes:defaultValue.valueData];
+  XCTAssertEqualObjects(message.defaultBytes, defaultBytes);
+  XCTAssertTrue(message.hasDefaultBytes);
+  [message setDefaultBytes:nil];
+  XCTAssertEqualObjects(message.defaultBytes, defaultBytes);
+  XCTAssertFalse(message.hasDefaultBytes);
+  message.hasDefaultBytes = NO;
+  XCTAssertFalse(message.hasDefaultBytes);
+  XCTAssertEqualObjects(message.defaultBytes, defaultBytes);
+
+  // Test optional string.
+  XCTAssertFalse(message.hasOptionalString);
+  XCTAssertEqualObjects(message.optionalString, @"");
+  XCTAssertFalse(message.hasOptionalString);
+  message.optionalString = nil;
+  XCTAssertFalse(message.hasOptionalString);
+  XCTAssertEqualObjects(message.optionalString, @"");
+  NSString *string = @"string";
+  message.optionalString = string;
+  XCTAssertEqualObjects(message.optionalString, string);
+  XCTAssertTrue(message.hasOptionalString);
+  message.optionalString = nil;
+  XCTAssertFalse(message.hasOptionalString);
+  XCTAssertEqualObjects(message.optionalString, @"");
+
+  // Test optional data.
+  XCTAssertFalse(message.hasOptionalBytes);
+  XCTAssertEqualObjects(message.optionalBytes, GPBEmptyNSData());
+  XCTAssertFalse(message.hasOptionalBytes);
+  message.optionalBytes = nil;
+  XCTAssertFalse(message.hasOptionalBytes);
+  XCTAssertEqualObjects(message.optionalBytes, GPBEmptyNSData());
+  NSData *data = [@"bytes" dataUsingEncoding:NSUTF8StringEncoding];
+  message.optionalBytes = data;
+  XCTAssertEqualObjects(message.optionalBytes, data);
+  XCTAssertTrue(message.hasOptionalBytes);
+  message.optionalBytes = nil;
+  XCTAssertFalse(message.hasOptionalBytes);
+  XCTAssertEqualObjects(message.optionalBytes, GPBEmptyNSData());
+
+  // Test lazy message setting
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  XCTAssertNotNil(message.optionalLazyMessage);
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  message.hasOptionalLazyMessage = NO;
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  XCTAssertNotNil(message.optionalLazyMessage);
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  message.optionalLazyMessage = nil;
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+
+  // Test nested messages
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  message.optionalLazyMessage.bb = 1;
+  XCTAssertTrue(message.hasOptionalLazyMessage);
+  XCTAssertEqual(message.optionalLazyMessage.bb, 1);
+  XCTAssertNotNil(message.optionalLazyMessage);
+  message.optionalLazyMessage = nil;
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  XCTAssertEqual(message.optionalLazyMessage.bb, 0);
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+  XCTAssertNotNil(message.optionalLazyMessage);
+
+  // -testDefaultSubMessages tests the "defaulting" handling of fields
+  // containing messages.
+}
+
+- (void)testRepeatedSetters {
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFields:message repeatedCount:kGPBDefaultRepeatCount];
+  [self modifyRepeatedFields:message];
+  [self assertRepeatedFieldsModified:message
+                       repeatedCount:kGPBDefaultRepeatCount];
+}
+
+- (void)testClear {
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFields:message repeatedCount:kGPBDefaultRepeatCount];
+  [self clearAllFields:message];
+  [self assertClear:message];
+  TestAllTypes *message2 = [TestAllTypes message];
+  XCTAssertEqualObjects(message, message2);
+}
+
+- (void)testClearKVC {
+  TestAllTypes *message = [TestAllTypes message];
+  [self setAllFields:message repeatedCount:kGPBDefaultRepeatCount];
+  [self clearAllFields:message];
+  [self assertClear:message];
+  [self assertClearKVC:message];
+}
+
+- (void)testClearExtension {
+  // clearExtension() is not actually used in TestUtil, so try it manually.
+  GPBMessage *message1 = [TestAllExtensions message];
+  [message1 setExtension:[UnittestRoot optionalInt32Extension] value:@1];
+
+  XCTAssertTrue([message1 hasExtension:[UnittestRoot optionalInt32Extension]]);
+  [message1 clearExtension:[UnittestRoot optionalInt32Extension]];
+  XCTAssertFalse([message1 hasExtension:[UnittestRoot optionalInt32Extension]]);
+
+  GPBMessage *message2 = [TestAllExtensions message];
+  [message2 addExtension:[UnittestRoot repeatedInt32Extension] value:@1];
+
+  XCTAssertEqual(
+      [[message2 getExtension:[UnittestRoot repeatedInt32Extension]] count],
+      (NSUInteger)1);
+  [message2 clearExtension:[UnittestRoot repeatedInt32Extension]];
+  XCTAssertEqual(
+      [[message2 getExtension:[UnittestRoot repeatedInt32Extension]] count],
+      (NSUInteger)0);
+
+  // Clearing an unset extension field shouldn't make the target message
+  // visible.
+  GPBMessage *message3 = [TestAllExtensions message];
+  GPBMessage *extension_msg =
+      [message3 getExtension:[UnittestObjcRoot recursiveExtension]];
+  XCTAssertFalse([message3 hasExtension:[UnittestObjcRoot recursiveExtension]]);
+  [extension_msg clearExtension:[UnittestRoot optionalInt32Extension]];
+  XCTAssertFalse([message3 hasExtension:[UnittestObjcRoot recursiveExtension]]);
+}
+
+- (void)testDefaultingSubMessages {
+  TestAllTypes *message = [TestAllTypes message];
+
+  // Initially they should all not have values.
+
+  XCTAssertFalse(message.hasOptionalGroup);
+  XCTAssertFalse(message.hasOptionalNestedMessage);
+  XCTAssertFalse(message.hasOptionalForeignMessage);
+  XCTAssertFalse(message.hasOptionalImportMessage);
+  XCTAssertFalse(message.hasOptionalPublicImportMessage);
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+
+  // They should auto create something when fetched.
+
+  TestAllTypes_OptionalGroup *optionalGroup = [message.optionalGroup retain];
+  TestAllTypes_NestedMessage *optionalNestedMessage =
+      [message.optionalNestedMessage retain];
+  ForeignMessage *optionalForeignMessage =
+      [message.optionalForeignMessage retain];
+  ImportMessage *optionalImportMessage = [message.optionalImportMessage retain];
+  PublicImportMessage *optionalPublicImportMessage =
+      [message.optionalPublicImportMessage retain];
+  TestAllTypes_NestedMessage *optionalLazyMessage =
+      [message.optionalLazyMessage retain];
+
+  XCTAssertNotNil(optionalGroup);
+  XCTAssertNotNil(optionalNestedMessage);
+  XCTAssertNotNil(optionalForeignMessage);
+  XCTAssertNotNil(optionalImportMessage);
+  XCTAssertNotNil(optionalPublicImportMessage);
+  XCTAssertNotNil(optionalLazyMessage);
+
+  // Although they were created, they should not respond to hasValue until that
+  // submessage is mutated.
+
+  XCTAssertFalse(message.hasOptionalGroup);
+  XCTAssertFalse(message.hasOptionalNestedMessage);
+  XCTAssertFalse(message.hasOptionalForeignMessage);
+  XCTAssertFalse(message.hasOptionalImportMessage);
+  XCTAssertFalse(message.hasOptionalPublicImportMessage);
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+
+  // And they set that value back in to the message since the value created was
+  // mutable (so a second fetch should give the same object).
+
+  XCTAssertEqual(message.optionalGroup, optionalGroup);
+  XCTAssertEqual(message.optionalNestedMessage, optionalNestedMessage);
+  XCTAssertEqual(message.optionalForeignMessage, optionalForeignMessage);
+  XCTAssertEqual(message.optionalImportMessage, optionalImportMessage);
+  XCTAssertEqual(message.optionalPublicImportMessage,
+                 optionalPublicImportMessage);
+  XCTAssertEqual(message.optionalLazyMessage, optionalLazyMessage);
+
+  // And the default objects for a second message should be distinct (again,
+  // since they are mutable, each needs their own copy).
+
+  TestAllTypes *message2 = [TestAllTypes message];
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(message2.optionalGroup, optionalGroup);
+  XCTAssertNotEqual(message2.optionalNestedMessage, optionalNestedMessage);
+  XCTAssertNotEqual(message2.optionalForeignMessage, optionalForeignMessage);
+  XCTAssertNotEqual(message2.optionalImportMessage, optionalImportMessage);
+  XCTAssertNotEqual(message2.optionalPublicImportMessage,
+                    optionalPublicImportMessage);
+  XCTAssertNotEqual(message2.optionalLazyMessage, optionalLazyMessage);
+
+  // Setting the values to nil will clear the has flag, and on next access you
+  // get back new submessages.
+
+  message.optionalGroup = nil;
+  message.optionalNestedMessage = nil;
+  message.optionalForeignMessage = nil;
+  message.optionalImportMessage = nil;
+  message.optionalPublicImportMessage = nil;
+  message.optionalLazyMessage = nil;
+
+  XCTAssertFalse(message.hasOptionalGroup);
+  XCTAssertFalse(message.hasOptionalNestedMessage);
+  XCTAssertFalse(message.hasOptionalForeignMessage);
+  XCTAssertFalse(message.hasOptionalImportMessage);
+  XCTAssertFalse(message.hasOptionalPublicImportMessage);
+  XCTAssertFalse(message.hasOptionalLazyMessage);
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(message.optionalGroup, optionalGroup);
+  XCTAssertNotEqual(message.optionalNestedMessage, optionalNestedMessage);
+  XCTAssertNotEqual(message.optionalForeignMessage, optionalForeignMessage);
+  XCTAssertNotEqual(message.optionalImportMessage, optionalImportMessage);
+  XCTAssertNotEqual(message.optionalPublicImportMessage,
+                    optionalPublicImportMessage);
+  XCTAssertNotEqual(message.optionalLazyMessage, optionalLazyMessage);
+
+  [optionalGroup release];
+  [optionalNestedMessage release];
+  [optionalForeignMessage release];
+  [optionalImportMessage release];
+  [optionalPublicImportMessage release];
+  [optionalLazyMessage release];
+}
+
+- (void)testMultiplePointersToAutocreatedMessage {
+  // Multiple objects pointing to the same autocreated message.
+  TestAllTypes *message = [TestAllTypes message];
+  TestAllTypes *message2 = [TestAllTypes message];
+  message2.optionalGroup = message.optionalGroup;
+  XCTAssertTrue([message2 hasOptionalGroup]);
+  XCTAssertFalse([message hasOptionalGroup]);
+  message2.optionalGroup.a = 42;
+  XCTAssertTrue([message hasOptionalGroup]);
+  XCTAssertTrue([message2 hasOptionalGroup]);
+}
+
+- (void)testCopyWithAutocreatedMessage {
+  // Mutable copy should not copy autocreated messages.
+  TestAllTypes *message = [TestAllTypes message];
+  message.optionalGroup.a = 42;
+  XCTAssertNotNil(message.optionalNestedMessage);
+  TestAllTypes *message2 = [[message copy] autorelease];
+  XCTAssertTrue([message2 hasOptionalGroup]);
+  XCTAssertFalse([message2 hasOptionalNestedMessage]);
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(message.optionalNestedMessage,
+                    message2.optionalNestedMessage);
+}
+
+- (void)testClearAutocreatedSubmessage {
+  // Call clear on an intermediate submessage should cause it to get recreated
+  // on the next call.
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  TestRecursiveMessage *message_inner = [message.a.a.a retain];
+  XCTAssertNotNil(message_inner);
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(message_inner, message.a.a));
+  [message.a.a clear];
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(message_inner, message.a.a));
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(message.a.a.a, message_inner);
+  [message_inner release];
+}
+
+- (void)testRetainAutocreatedSubmessage {
+  // Should be able to retain autocreated submessage while the creator is
+  // dealloced.
+  TestAllTypes *message = [TestAllTypes message];
+
+  ForeignMessage *subMessage;
+  @autoreleasepool {
+    TestAllTypes *message2 = [TestAllTypes message];
+    subMessage = message2.optionalForeignMessage; // Autocreated
+    message.optionalForeignMessage = subMessage;
+    XCTAssertTrue(GPBWasMessageAutocreatedBy(message.optionalForeignMessage,
+                                             message2));
+  }
+
+  // Should be the same object, and should still be live.
+  XCTAssertEqual(message.optionalForeignMessage, subMessage);
+  XCTAssertNotNil([subMessage description]);
+}
+
+- (void)testSetNilAutocreatedSubmessage {
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  TestRecursiveMessage *message_inner = [message.a.a retain];
+  XCTAssertFalse([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+  message.a.a = nil;
+
+  // |message.a| has to be made visible, but |message.a.a| was set to nil so
+  // shouldn't be.
+  XCTAssertTrue([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+
+  // Setting submessage to nil should cause it to lose its creator.
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(message_inner, message.a));
+
+  // After setting to nil, getting it again should create a new autocreated
+  // message.
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(message.a.a, message_inner);
+
+  [message_inner release];
+}
+
+- (void)testSetDoesntHaveAutocreatedSubmessage {
+  // Clearing submessage (set has == NO) should NOT cause it to lose its
+  // creator.
+  TestAllTypes *message = [TestAllTypes message];
+  TestAllTypes_NestedMessage *nestedMessage = message.optionalNestedMessage;
+  XCTAssertFalse([message hasOptionalNestedMessage]);
+  [message setHasOptionalNestedMessage:NO];
+  XCTAssertFalse([message hasOptionalNestedMessage]);
+  XCTAssertEqual(message.optionalNestedMessage, nestedMessage);
+}
+
+- (void)testSetAutocreatedMessageBecomesVisible {
+  // Setting a value should cause the submessage to appear to its creator.
+  // Test this several levels deep.
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  message.a.a.a.a.i = 42;
+  XCTAssertTrue([message hasA]);
+  XCTAssertTrue([message.a hasA]);
+  XCTAssertTrue([message.a.a hasA]);
+  XCTAssertTrue([message.a.a.a hasA]);
+  XCTAssertFalse([message.a.a.a.a hasA]);
+  XCTAssertEqual(message.a.a.a.a.i, 42);
+}
+
+- (void)testClearUnsetFieldOfAutocreatedMessage {
+  // Clearing an unset field should not cause the submessage to appear to its
+  // creator.
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  message.a.a.a.a.hasI = NO;
+  XCTAssertFalse([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+  XCTAssertFalse([message.a.a hasA]);
+  XCTAssertFalse([message.a.a.a hasA]);
+}
+
+- (void)testAutocreatedSubmessageAssignSkip {
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  TestRecursiveMessage *messageLevel1 = [message.a retain];
+  TestRecursiveMessage *messageLevel2 = [message.a.a retain];
+  TestRecursiveMessage *messageLevel3 = [message.a.a.a retain];
+  TestRecursiveMessage *messageLevel4 = [message.a.a.a.a retain];
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel1, message));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel2, messageLevel1));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel3, messageLevel2));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel4, messageLevel3));
+
+  // Test skipping over an autocreated submessage and ensure it gets unset.
+  message.a = message.a.a;
+  XCTAssertEqual(message.a, messageLevel2);
+  XCTAssertTrue([message hasA]);
+  XCTAssertEqual(message.a.a, messageLevel3);
+  XCTAssertFalse([message.a hasA]);
+  XCTAssertEqual(message.a.a.a, messageLevel4);
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(messageLevel1,
+                                            message));  // Because it was orphaned.
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel2, messageLevel1));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel3, messageLevel2));
+
+  [messageLevel1 release];
+  [messageLevel2 release];
+  [messageLevel3 release];
+  [messageLevel4 release];
+}
+
+- (void)testAutocreatedSubmessageAssignLoop {
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  TestRecursiveMessage *messageLevel1 = [message.a retain];
+  TestRecursiveMessage *messageLevel2 = [message.a.a retain];
+  TestRecursiveMessage *messageLevel3 = [message.a.a.a retain];
+  TestRecursiveMessage *messageLevel4 = [message.a.a.a.a retain];
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel1, message));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel2, messageLevel1));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel3, messageLevel2));
+  XCTAssertTrue(GPBWasMessageAutocreatedBy(messageLevel4, messageLevel3));
+
+  // Test a property with a loop. You'd never do this but at least ensure the
+  // autocreated submessages behave sanely.
+  message.a.a = message.a;
+  XCTAssertTrue([message hasA]);
+  XCTAssertEqual(message.a, messageLevel1);
+  XCTAssertTrue([message.a hasA]);
+  XCTAssertEqual(message.a.a, messageLevel1);
+  XCTAssertTrue([message.a.a hasA]);
+  XCTAssertEqual(message.a.a.a, messageLevel1);
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(messageLevel1,
+                                            message));  // Because it was assigned.
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(messageLevel2,
+                                            messageLevel1));  // Because it was orphaned.
+  XCTAssertFalse([messageLevel2 hasA]);
+
+  // Break the retain loop.
+  message.a.a = nil;
+  XCTAssertTrue([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+
+  [messageLevel1 release];
+  [messageLevel2 release];
+  [messageLevel3 release];
+  [messageLevel4 release];
+}
+
+- (void)testSetAutocreatedSubmessage {
+  // Setting autocreated submessage to another value should cause the old one to
+  // lose its creator.
+  TestAllTypes *message = [TestAllTypes message];
+  TestAllTypes_NestedMessage *nestedMessage =
+      [message.optionalNestedMessage retain];
+
+  message.optionalNestedMessage = [TestAllTypes_NestedMessage message];
+  XCTAssertTrue([message hasOptionalNestedMessage]);
+  XCTAssertTrue(message.optionalNestedMessage != nestedMessage);
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(nestedMessage, message));
+
+  [nestedMessage release];
+}
+
+- (void)testAutocreatedUnknownFields {
+  // Doing anything with (except reading) unknown fields should cause the
+  // submessage to become visible.
+  TestAllTypes *message = [TestAllTypes message];
+  XCTAssertNotNil(message.optionalNestedMessage);
+  XCTAssertFalse([message hasOptionalNestedMessage]);
+  XCTAssertNil(message.optionalNestedMessage.unknownFields);
+  XCTAssertFalse([message hasOptionalNestedMessage]);
+
+  GPBUnknownFieldSet *unknownFields =
+      [[[GPBUnknownFieldSet alloc] init] autorelease];
+  message.optionalNestedMessage.unknownFields = unknownFields;
+  XCTAssertTrue([message hasOptionalNestedMessage]);
+
+  message.optionalNestedMessage = nil;
+  XCTAssertFalse([message hasOptionalNestedMessage]);
+  [message.optionalNestedMessage setUnknownFields:unknownFields];
+  XCTAssertTrue([message hasOptionalNestedMessage]);
+}
+
+- (void)testSetAutocreatedSubmessageToSelf {
+  // Setting submessage to itself should cause it to become visible.
+  TestAllTypes *message = [TestAllTypes message];
+  XCTAssertNotNil(message.optionalNestedMessage);
+  XCTAssertFalse([message hasOptionalNestedMessage]);
+  message.optionalNestedMessage = message.optionalNestedMessage;
+  XCTAssertTrue([message hasOptionalNestedMessage]);
+}
+
+- (void)testAutocreatedSubmessageMemoryLeaks {
+  // Test for memory leaks with autocreated submessages.
+  TestRecursiveMessage *message;
+  TestRecursiveMessage *messageLevel1;
+  TestRecursiveMessage *messageLevel2;
+  TestRecursiveMessage *messageLevel3;
+  TestRecursiveMessage *messageLevel4;
+  @autoreleasepool {
+    message = [[TestRecursiveMessage alloc] init];
+    messageLevel1 = [message.a retain];
+    messageLevel2 = [message.a.a retain];
+    messageLevel3 = [message.a.a.a retain];
+    messageLevel4 = [message.a.a.a.a retain];
+    message.a.i = 1;
+  }
+
+  XCTAssertEqual(message.retainCount, (NSUInteger)1);
+  [message release];
+  XCTAssertEqual(messageLevel1.retainCount, (NSUInteger)1);
+  [messageLevel1 release];
+  XCTAssertEqual(messageLevel2.retainCount, (NSUInteger)1);
+  [messageLevel2 release];
+  XCTAssertEqual(messageLevel3.retainCount, (NSUInteger)1);
+  [messageLevel3 release];
+  XCTAssertEqual(messageLevel4.retainCount, (NSUInteger)1);
+  [messageLevel4 release];
+}
+
+- (void)testDefaultingArrays {
+  // Basic tests for default creation of arrays in a message.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message2 =
+      [TestRecursiveMessageWithRepeatedField message];
+
+  // Simply accessing the array should not make any fields visible.
+  XCTAssertNotNil(message.a.a.iArray);
+  XCTAssertFalse([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+  XCTAssertNotNil(message2.a.a.strArray);
+  XCTAssertFalse([message2 hasA]);
+  XCTAssertFalse([message2.a hasA]);
+
+  // But adding an element to the array should.
+  [message.a.a.iArray addValue:42];
+  XCTAssertTrue([message hasA]);
+  XCTAssertTrue([message.a hasA]);
+  XCTAssertEqual([message.a.a.iArray count], (NSUInteger)1);
+  [message2.a.a.strArray addObject:@"foo"];
+  XCTAssertTrue([message2 hasA]);
+  XCTAssertTrue([message2.a hasA]);
+  XCTAssertEqual([message2.a.a.strArray count], (NSUInteger)1);
+}
+
+- (void)testAutocreatedArrayShared {
+  // Multiple objects pointing to the same array.
+  TestRecursiveMessageWithRepeatedField *message1a =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message1b =
+      [TestRecursiveMessageWithRepeatedField message];
+  message1a.a.iArray = message1b.a.iArray;
+  XCTAssertTrue([message1a hasA]);
+  XCTAssertFalse([message1b hasA]);
+  [message1a.a.iArray addValue:1];
+  XCTAssertTrue([message1a hasA]);
+  XCTAssertTrue([message1b hasA]);
+  XCTAssertEqual(message1a.a.iArray, message1b.a.iArray);
+
+  TestRecursiveMessageWithRepeatedField *message2a =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message2b =
+      [TestRecursiveMessageWithRepeatedField message];
+  message2a.a.strArray = message2b.a.strArray;
+  XCTAssertTrue([message2a hasA]);
+  XCTAssertFalse([message2b hasA]);
+  [message2a.a.strArray addObject:@"bar"];
+  XCTAssertTrue([message2a hasA]);
+  XCTAssertTrue([message2b hasA]);
+  XCTAssertEqual(message2a.a.strArray, message2b.a.strArray);
+}
+
+- (void)testAutocreatedArrayCopy {
+  // Copy should not copy autocreated arrays.
+  TestAllTypes *message = [TestAllTypes message];
+  XCTAssertNotNil(message.repeatedStringArray);
+  XCTAssertNotNil(message.repeatedInt32Array);
+  TestAllTypes *message2 = [[message copy] autorelease];
+  // Pointer conparisions.
+  XCTAssertNotEqual(message.repeatedStringArray, message2.repeatedStringArray);
+  XCTAssertNotEqual(message.repeatedInt32Array, message2.repeatedInt32Array);
+
+  // Mutable copy should copy empty arrays that were explicitly set (end up
+  // with different objects that are equal).
+  TestAllTypes *message3 = [TestAllTypes message];
+  message3.repeatedInt32Array = [GPBInt32Array arrayWithValue:42];
+  message3.repeatedStringArray = [NSMutableArray arrayWithObject:@"wee"];
+  XCTAssertNotNil(message.repeatedInt32Array);
+  XCTAssertNotNil(message.repeatedStringArray);
+  TestAllTypes *message4 = [[message3 copy] autorelease];
+  XCTAssertNotEqual(message3.repeatedInt32Array, message4.repeatedInt32Array);
+  XCTAssertEqualObjects(message3.repeatedInt32Array,
+                        message4.repeatedInt32Array);
+  XCTAssertNotEqual(message3.repeatedStringArray, message4.repeatedStringArray);
+  XCTAssertEqualObjects(message3.repeatedStringArray,
+                        message4.repeatedStringArray);
+}
+
+- (void)testAutocreatedArrayRetain {
+  // Should be able to retain autocreated array while the creator is dealloced.
+  TestAllTypes *message = [TestAllTypes message];
+
+  @autoreleasepool {
+    TestAllTypes *message2 = [TestAllTypes message];
+    message.repeatedInt32Array = message2.repeatedInt32Array;
+    message.repeatedStringArray = message2.repeatedStringArray;
+    // Pointer conparision
+    XCTAssertEqual(message.repeatedInt32Array->_autocreator, message2);
+    XCTAssertTrue([message.repeatedStringArray
+        isKindOfClass:[GPBAutocreatedArray class]]);
+    XCTAssertEqual(
+        ((GPBAutocreatedArray *)message.repeatedStringArray)->_autocreator,
+        message2);
+  }
+
+  XCTAssertNil(message.repeatedInt32Array->_autocreator);
+  XCTAssertTrue(
+      [message.repeatedStringArray isKindOfClass:[GPBAutocreatedArray class]]);
+  XCTAssertNil(
+      ((GPBAutocreatedArray *)message.repeatedStringArray)->_autocreator);
+}
+
+- (void)testSetNilAutocreatedArray {
+  // Setting array to nil should cause it to lose its delegate.
+  TestAllTypes *message = [TestAllTypes message];
+  GPBInt32Array *repeatedInt32Array = [message.repeatedInt32Array retain];
+  GPBAutocreatedArray *repeatedStringArray =
+      (GPBAutocreatedArray *)[message.repeatedStringArray retain];
+  XCTAssertTrue([repeatedStringArray isKindOfClass:[GPBAutocreatedArray class]]);
+  XCTAssertEqual(repeatedInt32Array->_autocreator, message);
+  XCTAssertEqual(repeatedStringArray->_autocreator, message);
+  message.repeatedInt32Array = nil;
+  message.repeatedStringArray = nil;
+  XCTAssertNil(repeatedInt32Array->_autocreator);
+  XCTAssertNil(repeatedStringArray->_autocreator);
+  [repeatedInt32Array release];
+  [repeatedStringArray release];
+}
+
+- (void)testReplaceAutocreatedArray {
+  // Replacing array should orphan the old one and cause its creator to become
+  // visible.
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.iArray);
+    XCTAssertFalse([message hasA]);
+    GPBInt32Array *iArray = [message.a.iArray retain];
+    XCTAssertEqual(iArray->_autocreator, message.a);  // Pointer comparision
+    message.a.iArray = [GPBInt32Array arrayWithValue:1];
+    XCTAssertTrue([message hasA]);
+    XCTAssertNotEqual(message.a.iArray, iArray);  // Pointer comparision
+    XCTAssertNil(iArray->_autocreator);
+    [iArray release];
+  }
+
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.strArray);
+    XCTAssertFalse([message hasA]);
+    GPBAutocreatedArray *strArray =
+        (GPBAutocreatedArray *)[message.a.strArray retain];
+    XCTAssertTrue([strArray isKindOfClass:[GPBAutocreatedArray class]]);
+    XCTAssertEqual(strArray->_autocreator, message.a);  // Pointer comparision
+    message.a.strArray = [NSMutableArray arrayWithObject:@"foo"];
+    XCTAssertTrue([message hasA]);
+    XCTAssertNotEqual(message.a.strArray, strArray);  // Pointer comparision
+    XCTAssertNil(strArray->_autocreator);
+    [strArray release];
+  }
+}
+
+- (void)testSetAutocreatedArrayToSelf {
+  // Setting array to itself should cause it to become visible.
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.iArray);
+    XCTAssertFalse([message hasA]);
+    message.a.iArray = message.a.iArray;
+    XCTAssertTrue([message hasA]);
+    XCTAssertNil(message.a.iArray->_autocreator);
+  }
+
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.strArray);
+    XCTAssertFalse([message hasA]);
+    message.a.strArray = message.a.strArray;
+    XCTAssertTrue([message hasA]);
+    XCTAssertTrue([message.a.strArray isKindOfClass:[GPBAutocreatedArray class]]);
+    XCTAssertNil(((GPBAutocreatedArray *)message.a.strArray)->_autocreator);
+  }
+}
+
+- (void)testAutocreatedArrayRemoveAllValues {
+  // Calling removeAllValues on autocreated array should not cause it to be
+  // visible.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  [message.a.iArray removeAll];
+  XCTAssertFalse([message hasA]);
+  [message.a.strArray removeAllObjects];
+  XCTAssertFalse([message hasA]);
+}
+
+- (void)testDefaultingMaps {
+  // Basic tests for default creation of maps in a message.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message2 =
+      [TestRecursiveMessageWithRepeatedField message];
+
+  // Simply accessing the map should not make any fields visible.
+  XCTAssertNotNil(message.a.a.iToI);
+  XCTAssertFalse([message hasA]);
+  XCTAssertFalse([message.a hasA]);
+  XCTAssertNotNil(message2.a.a.strToStr);
+  XCTAssertFalse([message2 hasA]);
+  XCTAssertFalse([message2.a hasA]);
+
+  // But adding an element to the map should.
+  [message.a.a.iToI setValue:100 forKey:200];
+  XCTAssertTrue([message hasA]);
+  XCTAssertTrue([message.a hasA]);
+  XCTAssertEqual([message.a.a.iToI count], (NSUInteger)1);
+  [message2.a.a.strToStr setObject:@"foo" forKey:@"bar"];
+  XCTAssertTrue([message2 hasA]);
+  XCTAssertTrue([message2.a hasA]);
+  XCTAssertEqual([message2.a.a.strToStr count], (NSUInteger)1);
+}
+
+- (void)testAutocreatedMapShared {
+  // Multiple objects pointing to the same map.
+  TestRecursiveMessageWithRepeatedField *message1a =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message1b =
+      [TestRecursiveMessageWithRepeatedField message];
+  message1a.a.iToI = message1b.a.iToI;
+  XCTAssertTrue([message1a hasA]);
+  XCTAssertFalse([message1b hasA]);
+  [message1a.a.iToI setValue:1 forKey:2];
+  XCTAssertTrue([message1a hasA]);
+  XCTAssertTrue([message1b hasA]);
+  XCTAssertEqual(message1a.a.iToI, message1b.a.iToI);
+
+  TestRecursiveMessageWithRepeatedField *message2a =
+      [TestRecursiveMessageWithRepeatedField message];
+  TestRecursiveMessageWithRepeatedField *message2b =
+      [TestRecursiveMessageWithRepeatedField message];
+  message2a.a.strToStr = message2b.a.strToStr;
+  XCTAssertTrue([message2a hasA]);
+  XCTAssertFalse([message2b hasA]);
+  [message2a.a.strToStr setObject:@"bar" forKey:@"foo"];
+  XCTAssertTrue([message2a hasA]);
+  XCTAssertTrue([message2b hasA]);
+  XCTAssertEqual(message2a.a.strToStr, message2b.a.strToStr);
+}
+
+- (void)testAutocreatedMapCopy {
+  // Copy should not copy autocreated maps.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  XCTAssertNotNil(message.strToStr);
+  XCTAssertNotNil(message.iToI);
+  TestRecursiveMessageWithRepeatedField *message2 =
+      [[message copy] autorelease];
+  // Pointer conparisions.
+  XCTAssertNotEqual(message.strToStr, message2.strToStr);
+  XCTAssertNotEqual(message.iToI, message2.iToI);
+
+  // Mutable copy should copy empty arrays that were explicitly set (end up
+  // with different objects that are equal).
+  TestRecursiveMessageWithRepeatedField *message3 =
+      [TestRecursiveMessageWithRepeatedField message];
+  message3.iToI = [GPBInt32Int32Dictionary dictionaryWithValue:10 forKey:20];
+  message3.strToStr =
+      [NSMutableDictionary dictionaryWithObject:@"abc" forKey:@"123"];
+  XCTAssertNotNil(message.iToI);
+  XCTAssertNotNil(message.iToI);
+  TestRecursiveMessageWithRepeatedField *message4 =
+      [[message3 copy] autorelease];
+  XCTAssertNotEqual(message3.iToI, message4.iToI);
+  XCTAssertEqualObjects(message3.iToI, message4.iToI);
+  XCTAssertNotEqual(message3.strToStr, message4.strToStr);
+  XCTAssertEqualObjects(message3.strToStr, message4.strToStr);
+}
+
+- (void)testAutocreatedMapRetain {
+  // Should be able to retain autocreated map while the creator is dealloced.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+
+  @autoreleasepool {
+    TestRecursiveMessageWithRepeatedField *message2 =
+        [TestRecursiveMessageWithRepeatedField message];
+    message.iToI = message2.iToI;
+    message.strToStr = message2.strToStr;
+    // Pointer conparision
+    XCTAssertEqual(message.iToI->_autocreator, message2);
+    XCTAssertTrue([message.strToStr
+        isKindOfClass:[GPBAutocreatedDictionary class]]);
+    XCTAssertEqual(
+        ((GPBAutocreatedDictionary *)message.strToStr)->_autocreator,
+        message2);
+  }
+
+  XCTAssertNil(message.iToI->_autocreator);
+  XCTAssertTrue(
+      [message.strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+  XCTAssertNil(
+      ((GPBAutocreatedDictionary *)message.strToStr)->_autocreator);
+}
+
+- (void)testSetNilAutocreatedMap {
+  // Setting map to nil should cause it to lose its delegate.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  GPBInt32Int32Dictionary *iToI = [message.iToI retain];
+  GPBAutocreatedDictionary *strToStr =
+      (GPBAutocreatedDictionary *)[message.strToStr retain];
+  XCTAssertTrue([strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+  XCTAssertEqual(iToI->_autocreator, message);
+  XCTAssertEqual(strToStr->_autocreator, message);
+  message.iToI = nil;
+  message.strToStr = nil;
+  XCTAssertNil(iToI->_autocreator);
+  XCTAssertNil(strToStr->_autocreator);
+  [iToI release];
+  [strToStr release];
+}
+
+- (void)testReplaceAutocreatedMap {
+  // Replacing map should orphan the old one and cause its creator to become
+  // visible.
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.iToI);
+    XCTAssertFalse([message hasA]);
+    GPBInt32Int32Dictionary *iToI = [message.a.iToI retain];
+    XCTAssertEqual(iToI->_autocreator, message.a);  // Pointer comparision
+    message.a.iToI = [GPBInt32Int32Dictionary dictionaryWithValue:6 forKey:7];
+    XCTAssertTrue([message hasA]);
+    XCTAssertNotEqual(message.a.iToI, iToI);  // Pointer comparision
+    XCTAssertNil(iToI->_autocreator);
+    [iToI release];
+  }
+
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.strToStr);
+    XCTAssertFalse([message hasA]);
+    GPBAutocreatedDictionary *strToStr =
+        (GPBAutocreatedDictionary *)[message.a.strToStr retain];
+    XCTAssertTrue([strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+    XCTAssertEqual(strToStr->_autocreator, message.a);  // Pointer comparision
+    message.a.strToStr =
+        [NSMutableDictionary dictionaryWithObject:@"abc" forKey:@"def"];
+    XCTAssertTrue([message hasA]);
+    XCTAssertNotEqual(message.a.strToStr, strToStr);  // Pointer comparision
+    XCTAssertNil(strToStr->_autocreator);
+    [strToStr release];
+  }
+}
+
+- (void)testSetAutocreatedMapToSelf {
+  // Setting map to itself should cause it to become visible.
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.iToI);
+    XCTAssertFalse([message hasA]);
+    message.a.iToI = message.a.iToI;
+    XCTAssertTrue([message hasA]);
+    XCTAssertNil(message.a.iToI->_autocreator);
+  }
+
+  {
+    TestRecursiveMessageWithRepeatedField *message =
+        [TestRecursiveMessageWithRepeatedField message];
+    XCTAssertNotNil(message.a);
+    XCTAssertNotNil(message.a.strToStr);
+    XCTAssertFalse([message hasA]);
+    message.a.strToStr = message.a.strToStr;
+    XCTAssertTrue([message hasA]);
+    XCTAssertTrue([message.a.strToStr isKindOfClass:[GPBAutocreatedDictionary class]]);
+    XCTAssertNil(((GPBAutocreatedDictionary *)message.a.strToStr)->_autocreator);
+  }
+}
+
+- (void)testAutocreatedMapRemoveAllValues {
+  // Calling removeAll on autocreated map should not cause it to be visible.
+  TestRecursiveMessageWithRepeatedField *message =
+      [TestRecursiveMessageWithRepeatedField message];
+  [message.a.iToI removeAll];
+  XCTAssertFalse([message hasA]);
+  [message.a.strToStr removeAllObjects];
+  XCTAssertFalse([message hasA]);
+}
+
+- (void)testExtensionAccessors {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [self setAllExtensions:message repeatedCount:kGPBDefaultRepeatCount];
+  [self assertAllExtensionsSet:message repeatedCount:kGPBDefaultRepeatCount];
+}
+
+- (void)testExtensionRepeatedSetters {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [self setAllExtensions:message repeatedCount:kGPBDefaultRepeatCount];
+  [self modifyRepeatedExtensions:message];
+  [self assertRepeatedExtensionsModified:message
+                           repeatedCount:kGPBDefaultRepeatCount];
+}
+
+- (void)testExtensionDefaults {
+  [self assertExtensionsClear:[TestAllExtensions message]];
+}
+
+- (void)testExtensionIsEquals {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [self setAllExtensions:message repeatedCount:kGPBDefaultRepeatCount];
+  [self modifyRepeatedExtensions:message];
+  TestAllExtensions *message2 = [TestAllExtensions message];
+  [self setAllExtensions:message2 repeatedCount:kGPBDefaultRepeatCount];
+  XCTAssertFalse([message isEqual:message2]);
+  message2 = [TestAllExtensions message];
+  [self setAllExtensions:message2 repeatedCount:kGPBDefaultRepeatCount];
+  [self modifyRepeatedExtensions:message2];
+  XCTAssertEqualObjects(message, message2);
+}
+
+- (void)testExtensionsMergeFrom {
+  TestAllExtensions *message = [TestAllExtensions message];
+  [self setAllExtensions:message repeatedCount:kGPBDefaultRepeatCount];
+  [self modifyRepeatedExtensions:message];
+
+  message = [TestAllExtensions message];
+  [self setAllExtensions:message repeatedCount:kGPBDefaultRepeatCount];
+  TestAllExtensions *message2 = [TestAllExtensions message];
+  [self modifyRepeatedExtensions:message2];
+  [message2 mergeFrom:message];
+
+  XCTAssertEqualObjects(message, message2);
+}
+
+- (void)testDefaultingExtensionMessages {
+  TestAllExtensions *message = [TestAllExtensions message];
+
+  // Initially they should all not have values.
+
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalGroupExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalGroupExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalNestedMessageExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalForeignMessageExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalImportMessageExtension]]);
+  XCTAssertFalse([message
+      hasExtension:[UnittestRoot optionalPublicImportMessageExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalLazyMessageExtension]]);
+
+  // They should auto create something when fetched.
+
+  TestAllTypes_OptionalGroup *optionalGroup =
+      [message getExtension:[UnittestRoot optionalGroupExtension]];
+  TestAllTypes_NestedMessage *optionalNestedMessage =
+      [message getExtension:[UnittestRoot optionalNestedMessageExtension]];
+  ForeignMessage *optionalForeignMessage =
+      [message getExtension:[UnittestRoot optionalForeignMessageExtension]];
+  ImportMessage *optionalImportMessage =
+      [message getExtension:[UnittestRoot optionalImportMessageExtension]];
+  PublicImportMessage *optionalPublicImportMessage = [message
+      getExtension:[UnittestRoot optionalPublicImportMessageExtension]];
+  TestAllTypes_NestedMessage *optionalLazyMessage =
+      [message getExtension:[UnittestRoot optionalLazyMessageExtension]];
+
+  XCTAssertNotNil(optionalGroup);
+  XCTAssertNotNil(optionalNestedMessage);
+  XCTAssertNotNil(optionalForeignMessage);
+  XCTAssertNotNil(optionalImportMessage);
+  XCTAssertNotNil(optionalPublicImportMessage);
+  XCTAssertNotNil(optionalLazyMessage);
+
+  // Although it auto-created empty messages, it should not show that it has
+  // them.
+
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalGroupExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalGroupExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalNestedMessageExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalForeignMessageExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalImportMessageExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalPublicImportMessageExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalLazyMessageExtension]]);
+
+  // And they set that value back in to the message since the value created was
+  // mutable (so a second fetch should give the same object).
+
+  XCTAssertEqual([message getExtension:[UnittestRoot optionalGroupExtension]],
+                 optionalGroup);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalNestedMessageExtension]],
+      optionalNestedMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalForeignMessageExtension]],
+      optionalForeignMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalImportMessageExtension]],
+      optionalImportMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalPublicImportMessageExtension]],
+      optionalPublicImportMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalLazyMessageExtension]],
+      optionalLazyMessage);
+
+  // And the default objects for a second message should be distinct (again,
+  // since they are mutable, each needs their own copy).
+
+  TestAllExtensions *message2 = [TestAllExtensions message];
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(
+      [message2 getExtension:[UnittestRoot optionalGroupExtension]],
+      optionalGroup);
+  XCTAssertNotEqual(
+      [message2 getExtension:[UnittestRoot optionalNestedMessageExtension]],
+      optionalNestedMessage);
+  XCTAssertNotEqual(
+      [message2 getExtension:[UnittestRoot optionalForeignMessageExtension]],
+      optionalForeignMessage);
+  XCTAssertNotEqual(
+      [message2 getExtension:[UnittestRoot optionalImportMessageExtension]],
+      optionalImportMessage);
+  XCTAssertNotEqual(
+      [message2 getExtension:[UnittestRoot optionalPublicImportMessageExtension]],
+      optionalPublicImportMessage);
+  XCTAssertNotEqual(
+      [message2 getExtension:[UnittestRoot optionalLazyMessageExtension]],
+      optionalLazyMessage);
+
+  // Clear values, and on next access you get back new submessages.
+
+  [message setExtension:[UnittestRoot optionalGroupExtension] value:nil];
+  [message setExtension:[UnittestRoot optionalGroupExtension] value:nil];
+  [message setExtension:[UnittestRoot optionalNestedMessageExtension]
+                  value:nil];
+  [message setExtension:[UnittestRoot optionalForeignMessageExtension]
+                  value:nil];
+  [message setExtension:[UnittestRoot optionalImportMessageExtension]
+                  value:nil];
+  [message setExtension:[UnittestRoot optionalPublicImportMessageExtension]
+                  value:nil];
+  [message setExtension:[UnittestRoot optionalLazyMessageExtension] value:nil];
+
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalGroupExtension]]);
+  XCTAssertFalse([message hasExtension:[UnittestRoot optionalGroupExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalNestedMessageExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalForeignMessageExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalImportMessageExtension]]);
+  XCTAssertFalse([message
+      hasExtension:[UnittestRoot optionalPublicImportMessageExtension]]);
+  XCTAssertFalse(
+      [message hasExtension:[UnittestRoot optionalLazyMessageExtension]]);
+
+  XCTAssertEqual([message getExtension:[UnittestRoot optionalGroupExtension]],
+                 optionalGroup);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalNestedMessageExtension]],
+      optionalNestedMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalForeignMessageExtension]],
+      optionalForeignMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalImportMessageExtension]],
+      optionalImportMessage);
+  XCTAssertEqual(
+      [message
+          getExtension:[UnittestRoot optionalPublicImportMessageExtension]],
+      optionalPublicImportMessage);
+  XCTAssertEqual(
+      [message getExtension:[UnittestRoot optionalLazyMessageExtension]],
+      optionalLazyMessage);
+}
+
+- (void)testMultiplePointersToAutocreatedExtension {
+  // 2 objects point to the same auto-created extension. One should "has" it.
+  // The other should not.
+  TestAllExtensions *message = [TestAllExtensions message];
+  TestAllExtensions *message2 = [TestAllExtensions message];
+  GPBExtensionDescriptor *extension = [UnittestRoot optionalGroupExtension];
+  [message setExtension:extension value:[message2 getExtension:extension]];
+  XCTAssertEqual([message getExtension:extension],
+                 [message2 getExtension:extension]);
+  XCTAssertFalse([message2 hasExtension:extension]);
+  XCTAssertTrue([message hasExtension:extension]);
+
+  TestAllTypes_OptionalGroup *extensionValue =
+      [message2 getExtension:extension];
+  extensionValue.a = 1;
+  XCTAssertTrue([message2 hasExtension:extension]);
+  XCTAssertTrue([message hasExtension:extension]);
+}
+
+- (void)testCopyWithAutocreatedExtension {
+  // Mutable copy shouldn't copy autocreated extensions.
+  TestAllExtensions *message = [TestAllExtensions message];
+  GPBExtensionDescriptor *optionalGroupExtension =
+      [UnittestRoot optionalGroupExtension];
+  GPBExtensionDescriptor *optionalNestedMessageExtesion =
+      [UnittestRoot optionalNestedMessageExtension];
+  TestAllTypes_OptionalGroup *optionalGroup =
+      [message getExtension:optionalGroupExtension];
+  optionalGroup.a = 42;
+  XCTAssertNotNil(optionalGroup);
+  XCTAssertNotNil([message getExtension:optionalNestedMessageExtesion]);
+  XCTAssertTrue([message hasExtension:optionalGroupExtension]);
+  XCTAssertFalse([message hasExtension:optionalNestedMessageExtesion]);
+
+  TestAllExtensions *message2 = [[message copy] autorelease];
+
+  // message2 should end up with its own copy of the optional group.
+  XCTAssertTrue([message2 hasExtension:optionalGroupExtension]);
+  XCTAssertEqualObjects([message getExtension:optionalGroupExtension],
+                        [message2 getExtension:optionalGroupExtension]);
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual([message getExtension:optionalGroupExtension],
+                    [message2 getExtension:optionalGroupExtension]);
+
+  XCTAssertFalse([message2 hasExtension:optionalNestedMessageExtesion]);
+  // Intentionally doing a pointer comparison (auto creation should be
+  // different)
+  XCTAssertNotEqual([message getExtension:optionalNestedMessageExtesion],
+                    [message2 getExtension:optionalNestedMessageExtesion]);
+}
+
+- (void)testClearMessageAutocreatedExtension {
+  // Call clear should cause it to recreate its autocreated extensions.
+  TestAllExtensions *message = [TestAllExtensions message];
+  GPBExtensionDescriptor *optionalGroupExtension =
+      [UnittestRoot optionalGroupExtension];
+  TestAllTypes_OptionalGroup *optionalGroup =
+      [[message getExtension:optionalGroupExtension] retain];
+  [message clear];
+  TestAllTypes_OptionalGroup *optionalGroupNew =
+      [message getExtension:optionalGroupExtension];
+
+  // Intentionally doing a pointer comparison.
+  XCTAssertNotEqual(optionalGroup, optionalGroupNew);
+  [optionalGroup release];
+}
+
+- (void)testRetainAutocreatedExtension {
+  // Should be able to retain autocreated extension while the creator is
+  // dealloced.
+  TestAllExtensions *message = [TestAllExtensions message];
+  GPBExtensionDescriptor *optionalGroupExtension =
+      [UnittestRoot optionalGroupExtension];
+
+  @autoreleasepool {
+    TestAllExtensions *message2 = [TestAllExtensions message];
+    [message setExtension:optionalGroupExtension
+                    value:[message2 getExtension:optionalGroupExtension]];
+    XCTAssertTrue(GPBWasMessageAutocreatedBy(
+        [message getExtension:optionalGroupExtension], message2));
+  }
+
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(
+      [message getExtension:optionalGroupExtension], message));
+}
+
+- (void)testClearAutocreatedExtension {
+  // Clearing autocreated extension should NOT cause it to lose its creator.
+  TestAllExtensions *message = [TestAllExtensions message];
+  GPBExtensionDescriptor *optionalGroupExtension =
+      [UnittestRoot optionalGroupExtension];
+  TestAllTypes_OptionalGroup *optionalGroup =
+      [[message getExtension:optionalGroupExtension] retain];
+  [message clearExtension:optionalGroupExtension];
+  TestAllTypes_OptionalGroup *optionalGroupNew =
+      [message getExtension:optionalGroupExtension];
+  XCTAssertEqual(optionalGroup, optionalGroupNew);
+  XCTAssertFalse([message hasExtension:optionalGroupExtension]);
+  [optionalGroup release];
+
+  // Clearing autocreated extension should not cause its creator to become
+  // visible
+  GPBExtensionDescriptor *recursiveExtension =
+      [UnittestObjcRoot recursiveExtension];
+  TestAllExtensions *message_lvl2 = [message getExtension:recursiveExtension];
+  TestAllExtensions *message_lvl3 =
+      [message_lvl2 getExtension:recursiveExtension];
+  [message_lvl3 clearExtension:recursiveExtension];
+  XCTAssertFalse([message hasExtension:recursiveExtension]);
+}
+
+- (void)testSetAutocreatedExtensionBecomesVisible {
+  // Setting an extension should cause the extension to appear to its creator.
+  // Test this several levels deep.
+  TestAllExtensions *message = [TestAllExtensions message];
+  GPBExtensionDescriptor *recursiveExtension =
+      [UnittestObjcRoot recursiveExtension];
+  TestAllExtensions *message_lvl2 = [message getExtension:recursiveExtension];
+  TestAllExtensions *message_lvl3 =
+      [message_lvl2 getExtension:recursiveExtension];
+  TestAllExtensions *message_lvl4 =
+      [message_lvl3 getExtension:recursiveExtension];
+  XCTAssertFalse([message hasExtension:recursiveExtension]);
+  XCTAssertFalse([message_lvl2 hasExtension:recursiveExtension]);
+  XCTAssertFalse([message_lvl3 hasExtension:recursiveExtension]);
+  XCTAssertFalse([message_lvl4 hasExtension:recursiveExtension]);
+  [message_lvl4 setExtension:[UnittestRoot optionalInt32Extension] value:@(1)];
+  XCTAssertTrue([message hasExtension:recursiveExtension]);
+  XCTAssertTrue([message_lvl2 hasExtension:recursiveExtension]);
+  XCTAssertTrue([message_lvl3 hasExtension:recursiveExtension]);
+  XCTAssertFalse([message_lvl4 hasExtension:recursiveExtension]);
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(message_lvl4, message_lvl3));
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(message_lvl3, message_lvl2));
+  XCTAssertFalse(GPBWasMessageAutocreatedBy(message_lvl2, message));
+}
+
+- (void)testSetAutocreatedExtensionToSelf {
+  // Setting extension to itself should cause it to become visible.
+  TestAllExtensions *message = [TestAllExtensions message];
+  GPBExtensionDescriptor *optionalGroupExtension =
+      [UnittestRoot optionalGroupExtension];
+  XCTAssertNotNil([message getExtension:optionalGroupExtension]);
+  XCTAssertFalse([message hasExtension:optionalGroupExtension]);
+  [message setExtension:optionalGroupExtension
+                  value:[message getExtension:optionalGroupExtension]];
+  XCTAssertTrue([message hasExtension:optionalGroupExtension]);
+}
+
+- (void)testAutocreatedExtensionMemoryLeaks {
+  GPBExtensionDescriptor *recursiveExtension =
+      [UnittestObjcRoot recursiveExtension];
+
+  // Test for memory leaks with autocreated extensions.
+  TestAllExtensions *message;
+  TestAllExtensions *message_lvl2;
+  TestAllExtensions *message_lvl3;
+  TestAllExtensions *message_lvl4;
+  @autoreleasepool {
+    message = [[TestAllExtensions alloc] init];
+    message_lvl2 = [[message getExtension:recursiveExtension] retain];
+    message_lvl3 = [[message_lvl2 getExtension:recursiveExtension] retain];
+    message_lvl4 = [[message_lvl3 getExtension:recursiveExtension] retain];
+    [message_lvl2 setExtension:[UnittestRoot optionalInt32Extension]
+                         value:@(1)];
+  }
+
+  XCTAssertEqual(message.retainCount, (NSUInteger)1);
+  @autoreleasepool {
+    [message release];
+  }
+  XCTAssertEqual(message_lvl2.retainCount, (NSUInteger)1);
+  @autoreleasepool {
+    [message_lvl2 release];
+  }
+  XCTAssertEqual(message_lvl3.retainCount, (NSUInteger)1);
+  @autoreleasepool {
+    [message_lvl3 release];
+  }
+  XCTAssertEqual(message_lvl4.retainCount, (NSUInteger)1);
+  [message_lvl4 release];
+}
+
+- (void)testSetExtensionWithAutocreatedValue {
+  GPBExtensionDescriptor *recursiveExtension =
+      [UnittestObjcRoot recursiveExtension];
+
+  TestAllExtensions *message;
+  @autoreleasepool {
+    message = [[TestAllExtensions alloc] init];
+    [message getExtension:recursiveExtension];
+  }
+
+  // This statements checks that the extension value isn't accidentally
+  // dealloced when removing it from the autocreated map.
+  [message setExtension:recursiveExtension
+                  value:[message getExtension:recursiveExtension]];
+  XCTAssertTrue([message hasExtension:recursiveExtension]);
+  [message release];
+}
+
+- (void)testRecursion {
+  TestRecursiveMessage *message = [TestRecursiveMessage message];
+  XCTAssertNotNil(message.a);
+  XCTAssertNotNil(message.a.a);
+  XCTAssertEqual(message.a.a.i, 0);
+}
+
+- (void)testGenerateAndParseUnknownMessage {
+  GPBUnknownFieldSet *unknowns =
+      [[[GPBUnknownFieldSet alloc] init] autorelease];
+  [unknowns mergeVarintField:123 value:456];
+  GPBMessage *message = [GPBMessage message];
+  [message setUnknownFields:unknowns];
+  NSData *data = [message data];
+  GPBMessage *message2 =
+      [GPBMessage parseFromData:data extensionRegistry:nil error:NULL];
+  XCTAssertEqualObjects(message, message2);
+}
+
+- (void)testDelimitedWriteAndParseMultipleMessages {
+  GPBUnknownFieldSet *unknowns1 =
+      [[[GPBUnknownFieldSet alloc] init] autorelease];
+  [unknowns1 mergeVarintField:123 value:456];
+  GPBMessage *message1 = [GPBMessage message];
+  [message1 setUnknownFields:unknowns1];
+
+  GPBUnknownFieldSet *unknowns2 =
+      [[[GPBUnknownFieldSet alloc] init] autorelease];
+  [unknowns2 mergeVarintField:789 value:987];
+  [unknowns2 mergeVarintField:654 value:321];
+  GPBMessage *message2 = [GPBMessage message];
+  [message2 setUnknownFields:unknowns2];
+
+  NSMutableData *delimitedData = [NSMutableData data];
+  [delimitedData appendData:[message1 delimitedData]];
+  [delimitedData appendData:[message2 delimitedData]];
+  GPBCodedInputStream *input =
+      [GPBCodedInputStream streamWithData:delimitedData];
+  GPBMessage *message3 = [GPBMessage parseDelimitedFromCodedInputStream:input
+                                                      extensionRegistry:nil
+                                                                  error:NULL];
+  GPBMessage *message4 = [GPBMessage parseDelimitedFromCodedInputStream:input
+                                                      extensionRegistry:nil
+                                                                  error:NULL];
+  XCTAssertEqualObjects(message1, message3);
+  XCTAssertEqualObjects(message2, message4);
+}
+
+- (void)testDuplicateEnums {
+  XCTAssertEqual(TestEnumWithDupValue_Foo1, TestEnumWithDupValue_Foo2);
+}
+
+- (void)testWeirdDefaults {
+  ObjcWeirdDefaults *message = [ObjcWeirdDefaults message];
+  GPBDescriptor *descriptor = [[message class] descriptor];
+  GPBFieldDescriptor *fieldDesc = [descriptor fieldWithName:@"foo"];
+  XCTAssertNotNil(fieldDesc);
+  XCTAssertTrue(fieldDesc.hasDefaultValue);
+  XCTAssertFalse(message.hasFoo);
+  XCTAssertEqualObjects(message.foo, @"");
+
+  fieldDesc = [descriptor fieldWithName:@"bar"];
+  XCTAssertNotNil(fieldDesc);
+  XCTAssertTrue(fieldDesc.hasDefaultValue);
+  XCTAssertFalse(message.hasBar);
+  XCTAssertEqualObjects(message.bar, GPBEmptyNSData());
+}
+
+- (void)testEnumDescriptorFromExtensionDescriptor {
+  GPBExtensionDescriptor *extDescriptor =
+      [UnittestRoot optionalForeignEnumExtension];
+  XCTAssertEqual(extDescriptor.dataType, GPBDataTypeEnum);
+  GPBEnumDescriptor *enumDescriptor = extDescriptor.enumDescriptor;
+  GPBEnumDescriptor *expectedDescriptor = ForeignEnum_EnumDescriptor();
+  XCTAssertEqualObjects(enumDescriptor, expectedDescriptor);
+}
+
+- (void)testEnumNaming {
+  // objectivec_helpers.cc has some interesting cases to deal with in
+  // EnumValueName/EnumValueShortName.  Confirm that things generated as
+  // expected.
+
+  // This block just has to compile to confirm we got the expected types/names.
+  // The *_IsValidValue() calls are just there to keep the projects warnings
+  // flags happy by providing use of the variables/values.
+
+  Foo aFoo = Foo_SerializedSize;
+  Foo_IsValidValue(aFoo);
+  aFoo = Foo_Size;
+  Foo_IsValidValue(aFoo);
+
+  Category_Enum aCat = Category_Enum_Red;
+  Category_Enum_IsValidValue(aCat);
+
+  Time aTime = Time_Base;
+  Time_IsValidValue(aTime);
+  aTime = Time_SomethingElse;
+  Time_IsValidValue(aTime);
+
+  // This block confirms the names in the decriptors is what we wanted.
+
+  GPBEnumDescriptor *descriptor;
+  NSString *valueName;
+
+  descriptor = Foo_EnumDescriptor();
+  XCTAssertNotNil(descriptor);
+  XCTAssertEqualObjects(@"Foo", descriptor.name);
+  valueName = [descriptor enumNameForValue:Foo_SerializedSize];
+  XCTAssertEqualObjects(@"Foo_SerializedSize", valueName);
+  valueName = [descriptor enumNameForValue:Foo_Size];
+  XCTAssertEqualObjects(@"Foo_Size", valueName);
+
+  descriptor = Category_Enum_EnumDescriptor();
+  XCTAssertNotNil(descriptor);
+  XCTAssertEqualObjects(@"Category_Enum", descriptor.name);
+  valueName = [descriptor enumNameForValue:Category_Enum_Red];
+  XCTAssertEqualObjects(@"Category_Enum_Red", valueName);
+
+  descriptor = Time_EnumDescriptor();
+  XCTAssertNotNil(descriptor);
+  XCTAssertEqualObjects(@"Time", descriptor.name);
+  valueName = [descriptor enumNameForValue:Time_Base];
+  XCTAssertEqualObjects(@"Time_Base", valueName);
+  valueName = [descriptor enumNameForValue:Time_SomethingElse];
+  XCTAssertEqualObjects(@"Time_SomethingElse", valueName);
+}
+
+- (void)testNegativeEnums {
+  EnumTestMsg *msg = [EnumTestMsg message];
+
+  // Defaults
+  XCTAssertEqual(msg.foo, EnumTestMsg_MyEnum_Zero);
+  XCTAssertEqual(msg.bar, EnumTestMsg_MyEnum_One);
+  XCTAssertEqual(msg.baz, EnumTestMsg_MyEnum_NegOne);
+  // Bounce to wire and back.
+  NSData *data = [msg data];
+  XCTAssertNotNil(data);
+  EnumTestMsg *msgPrime = [EnumTestMsg parseFromData:data error:NULL];
+  XCTAssertEqualObjects(msgPrime, msg);
+  XCTAssertEqual(msgPrime.foo, EnumTestMsg_MyEnum_Zero);
+  XCTAssertEqual(msgPrime.bar, EnumTestMsg_MyEnum_One);
+  XCTAssertEqual(msgPrime.baz, EnumTestMsg_MyEnum_NegOne);
+
+  // Other values
+  msg.bar = EnumTestMsg_MyEnum_Two;
+  msg.baz = EnumTestMsg_MyEnum_NegTwo;
+  XCTAssertEqual(msg.bar, EnumTestMsg_MyEnum_Two);
+  XCTAssertEqual(msg.baz, EnumTestMsg_MyEnum_NegTwo);
+  // Bounce to wire and back.
+  data = [msg data];
+  XCTAssertNotNil(data);
+  msgPrime = [EnumTestMsg parseFromData:data error:NULL];
+  XCTAssertEqualObjects(msgPrime, msg);
+  XCTAssertEqual(msgPrime.foo, EnumTestMsg_MyEnum_Zero);
+  XCTAssertEqual(msgPrime.bar, EnumTestMsg_MyEnum_Two);
+  XCTAssertEqual(msgPrime.baz, EnumTestMsg_MyEnum_NegTwo);
+
+  // Repeated field (shouldn't ever be an issue since developer has to use the
+  // right GPBArray methods themselves).
+  msg.mumbleArray = [GPBEnumArray
+      arrayWithValidationFunction:EnumTestMsg_MyEnum_IsValidValue];
+  [msg.mumbleArray addValue:EnumTestMsg_MyEnum_Zero];
+  [msg.mumbleArray addValue:EnumTestMsg_MyEnum_One];
+  [msg.mumbleArray addValue:EnumTestMsg_MyEnum_Two];
+  [msg.mumbleArray addValue:EnumTestMsg_MyEnum_NegOne];
+  [msg.mumbleArray addValue:EnumTestMsg_MyEnum_NegTwo];
+  XCTAssertEqual([msg.mumbleArray valueAtIndex:0], EnumTestMsg_MyEnum_Zero);
+  XCTAssertEqual([msg.mumbleArray valueAtIndex:1], EnumTestMsg_MyEnum_One);
+  XCTAssertEqual([msg.mumbleArray valueAtIndex:2], EnumTestMsg_MyEnum_Two);
+  XCTAssertEqual([msg.mumbleArray valueAtIndex:3], EnumTestMsg_MyEnum_NegOne);
+  XCTAssertEqual([msg.mumbleArray valueAtIndex:4], EnumTestMsg_MyEnum_NegTwo);
+  // Bounce to wire and back.
+  data = [msg data];
+  XCTAssertNotNil(data);
+  msgPrime = [EnumTestMsg parseFromData:data error:NULL];
+  XCTAssertEqualObjects(msgPrime, msg);
+  XCTAssertEqual([msgPrime.mumbleArray valueAtIndex:0],
+                 EnumTestMsg_MyEnum_Zero);
+  XCTAssertEqual([msgPrime.mumbleArray valueAtIndex:1], EnumTestMsg_MyEnum_One);
+  XCTAssertEqual([msgPrime.mumbleArray valueAtIndex:2], EnumTestMsg_MyEnum_Two);
+  XCTAssertEqual([msgPrime.mumbleArray valueAtIndex:3],
+                 EnumTestMsg_MyEnum_NegOne);
+  XCTAssertEqual([msgPrime.mumbleArray valueAtIndex:4],
+                 EnumTestMsg_MyEnum_NegTwo);
+}
+
+@end