objectivec/Tests/GPBDescriptorTests.m - external/github.com/google/protobuf - Git at Google

 // 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 "GPBDescriptor_PackagePrivate.h"
 #import "google/protobuf/Unittest.pbobjc.h"
 #import "google/protobuf/UnittestObjc.pbobjc.h"
 #import "google/protobuf/Descriptor.pbobjc.h"

 @interface DescriptorTests : GPBTestCase
 @end

 @implementation DescriptorTests

 - (void)testDescriptor_containingType {
   GPBDescriptor *testAllTypesDesc = [TestAllTypes descriptor];
   GPBDescriptor *nestedMessageDesc = [TestAllTypes_NestedMessage descriptor];
   XCTAssertNil(testAllTypesDesc.containingType);
   XCTAssertNotNil(nestedMessageDesc.containingType);
   XCTAssertEqual(nestedMessageDesc.containingType, testAllTypesDesc);  // Ptr comparison
 }

 - (void)testDescriptor_fullName {
   GPBDescriptor *testAllTypesDesc = [TestAllTypes descriptor];
   XCTAssertEqualObjects(testAllTypesDesc.fullName, @"protobuf_unittest.TestAllTypes");
   GPBDescriptor *nestedMessageDesc = [TestAllTypes_NestedMessage descriptor];
   XCTAssertEqualObjects(nestedMessageDesc.fullName, @"protobuf_unittest.TestAllTypes.NestedMessage");

   // Prefixes removed.
   GPBDescriptor *descDesc = [GPBDescriptorProto descriptor];
   XCTAssertEqualObjects(descDesc.fullName, @"google.protobuf.DescriptorProto");
   GPBDescriptor *descExtRngDesc = [GPBDescriptorProto_ExtensionRange descriptor];
   XCTAssertEqualObjects(descExtRngDesc.fullName, @"google.protobuf.DescriptorProto.ExtensionRange");

   // Things that get "_Class" added.
   GPBDescriptor *pointDesc = [Point_Class descriptor];
   XCTAssertEqualObjects(pointDesc.fullName, @"protobuf_unittest.Point");
   GPBDescriptor *pointRectDesc = [Point_Rect descriptor];
   XCTAssertEqualObjects(pointRectDesc.fullName, @"protobuf_unittest.Point.Rect");
 }

 - (void)testFieldDescriptor {
   GPBDescriptor *descriptor = [TestAllTypes descriptor];

   // Nested Enum
   GPBFieldDescriptor *fieldDescriptorWithName =
       [descriptor fieldWithName:@"optionalNestedEnum"];
   XCTAssertNotNil(fieldDescriptorWithName);
   GPBFieldDescriptor *fieldDescriptorWithNumber =
       [descriptor fieldWithNumber:21];
   XCTAssertNotNil(fieldDescriptorWithNumber);
   XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
   XCTAssertNotNil(fieldDescriptorWithNumber.enumDescriptor);
   XCTAssertEqualObjects(fieldDescriptorWithNumber.enumDescriptor.name,
                         @"TestAllTypes_NestedEnum");
   XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
   XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeEnum);

   // Foreign Enum
   fieldDescriptorWithName = [descriptor fieldWithName:@"optionalForeignEnum"];
   XCTAssertNotNil(fieldDescriptorWithName);
   fieldDescriptorWithNumber = [descriptor fieldWithNumber:22];
   XCTAssertNotNil(fieldDescriptorWithNumber);
   XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
   XCTAssertNotNil(fieldDescriptorWithNumber.enumDescriptor);
   XCTAssertEqualObjects(fieldDescriptorWithNumber.enumDescriptor.name,
                         @"ForeignEnum");
   XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
   XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeEnum);

   // Import Enum
   fieldDescriptorWithName = [descriptor fieldWithName:@"optionalImportEnum"];
   XCTAssertNotNil(fieldDescriptorWithName);
   fieldDescriptorWithNumber = [descriptor fieldWithNumber:23];
   XCTAssertNotNil(fieldDescriptorWithNumber);
   XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
   XCTAssertNotNil(fieldDescriptorWithNumber.enumDescriptor);
   XCTAssertEqualObjects(fieldDescriptorWithNumber.enumDescriptor.name,
                         @"ImportEnum");
   XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
   XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeEnum);

   // Nested Message
   fieldDescriptorWithName = [descriptor fieldWithName:@"optionalNestedMessage"];
   XCTAssertNotNil(fieldDescriptorWithName);
   fieldDescriptorWithNumber = [descriptor fieldWithNumber:18];
   XCTAssertNotNil(fieldDescriptorWithNumber);
   XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
   XCTAssertNil(fieldDescriptorWithNumber.enumDescriptor);
   XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
   XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeMessage);

   // Foreign Message
   fieldDescriptorWithName =
       [descriptor fieldWithName:@"optionalForeignMessage"];
   XCTAssertNotNil(fieldDescriptorWithName);
   fieldDescriptorWithNumber = [descriptor fieldWithNumber:19];
   XCTAssertNotNil(fieldDescriptorWithNumber);
   XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
   XCTAssertNil(fieldDescriptorWithNumber.enumDescriptor);
   XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
   XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeMessage);

   // Import Message
   fieldDescriptorWithName = [descriptor fieldWithName:@"optionalImportMessage"];
   XCTAssertNotNil(fieldDescriptorWithName);
   fieldDescriptorWithNumber = [descriptor fieldWithNumber:20];
   XCTAssertNotNil(fieldDescriptorWithNumber);
   XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
   XCTAssertNil(fieldDescriptorWithNumber.enumDescriptor);
   XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
   XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeMessage);

   // Some failed lookups.
   XCTAssertNil([descriptor fieldWithName:@"NOT THERE"]);
   XCTAssertNil([descriptor fieldWithNumber:9876543]);
 }

 - (void)testEnumDescriptor {
   GPBEnumDescriptor *descriptor = TestAllTypes_NestedEnum_EnumDescriptor();

   NSString *enumName = [descriptor enumNameForValue:1];
   XCTAssertNotNil(enumName);
   int32_t value;
   XCTAssertTrue(
       [descriptor getValue:&value forEnumName:@"TestAllTypes_NestedEnum_Foo"]);
   XCTAssertTrue(
       [descriptor getValue:NULL forEnumName:@"TestAllTypes_NestedEnum_Foo"]);
   XCTAssertEqual(value, TestAllTypes_NestedEnum_Foo);

   enumName = [descriptor enumNameForValue:2];
   XCTAssertNotNil(enumName);
   XCTAssertTrue(
       [descriptor getValue:&value forEnumName:@"TestAllTypes_NestedEnum_Bar"]);
   XCTAssertEqual(value, TestAllTypes_NestedEnum_Bar);

   enumName = [descriptor enumNameForValue:3];
   XCTAssertNotNil(enumName);
   XCTAssertTrue(
       [descriptor getValue:&value forEnumName:@"TestAllTypes_NestedEnum_Baz"]);
   XCTAssertEqual(value, TestAllTypes_NestedEnum_Baz);

   // TextFormat
   enumName = [descriptor textFormatNameForValue:1];
   XCTAssertNotNil(enumName);
   XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:@"FOO"]);
   XCTAssertEqual(value, TestAllTypes_NestedEnum_Foo);
   XCTAssertNil([descriptor textFormatNameForValue:99999]);

   // Bad values
   enumName = [descriptor enumNameForValue:0];
   XCTAssertNil(enumName);
   XCTAssertFalse([descriptor getValue:&value forEnumName:@"Unknown"]);
   XCTAssertFalse([descriptor getValue:NULL forEnumName:@"Unknown"]);
   XCTAssertFalse([descriptor getValue:&value
                           forEnumName:@"TestAllTypes_NestedEnum_Unknown"]);
   XCTAssertFalse([descriptor getValue:NULL
                           forEnumName:@"TestAllTypes_NestedEnum_Unknown"]);
   XCTAssertFalse([descriptor getValue:NULL forEnumTextFormatName:@"Unknown"]);
   XCTAssertFalse([descriptor getValue:&value forEnumTextFormatName:@"Unknown"]);
 }

 - (void)testEnumDescriptorIntrospection {
   GPBEnumDescriptor *descriptor = TestAllTypes_NestedEnum_EnumDescriptor();

   XCTAssertEqual(descriptor.enumNameCount, 4U);
   XCTAssertEqualObjects([descriptor getEnumNameForIndex:0],
                         @"TestAllTypes_NestedEnum_Foo");
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:0], @"FOO");
   XCTAssertEqualObjects([descriptor getEnumNameForIndex:1],
                  @"TestAllTypes_NestedEnum_Bar");
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:1], @"BAR");
   XCTAssertEqualObjects([descriptor getEnumNameForIndex:2],
                  @"TestAllTypes_NestedEnum_Baz");
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:2], @"BAZ");
   XCTAssertEqualObjects([descriptor getEnumNameForIndex:3],
                  @"TestAllTypes_NestedEnum_Neg");
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:3], @"NEG");
 }

 - (void)testEnumDescriptorIntrospectionWithAlias {
   GPBEnumDescriptor *descriptor = TestEnumWithDupValue_EnumDescriptor();
   NSString *enumName;
   int32_t value;

   XCTAssertEqual(descriptor.enumNameCount, 5U);

   enumName = [descriptor getEnumNameForIndex:0];
   XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Foo1");
   XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
   XCTAssertEqual(value, 1);
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:0], @"FOO1");

   enumName = [descriptor getEnumNameForIndex:1];
   XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Bar1");
   XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
   XCTAssertEqual(value, 2);
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:1], @"BAR1");

   enumName = [descriptor getEnumNameForIndex:2];
   XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Baz");
   XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
   XCTAssertEqual(value, 3);
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:2], @"BAZ");

   enumName = [descriptor getEnumNameForIndex:3];
   XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Foo2");
   XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
   XCTAssertEqual(value, 1);
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:3], @"FOO2");

   enumName = [descriptor getEnumNameForIndex:4];
   XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Bar2");
   XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
   XCTAssertEqual(value, 2);
   XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:4], @"BAR2");
 }

 - (void)testEnumAliasNameCollisions {
   GPBEnumDescriptor *descriptor = TestEnumObjCNameCollision_EnumDescriptor();
   NSString *textFormatName;
   int32_t value;

   XCTAssertEqual(descriptor.enumNameCount, 5U);

   XCTAssertEqualObjects([descriptor getEnumNameForIndex:0], @"TestEnumObjCNameCollision_Foo");
   textFormatName = [descriptor getEnumTextFormatNameForIndex:0];
   XCTAssertEqualObjects(textFormatName, @"FOO");
   XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
   XCTAssertEqual(value, 1);

   XCTAssertEqualObjects([descriptor getEnumNameForIndex:1], @"TestEnumObjCNameCollision_Foo");
   textFormatName = [descriptor getEnumTextFormatNameForIndex:1];
   XCTAssertEqualObjects(textFormatName, @"foo");
   XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
   XCTAssertEqual(value, 1);

   XCTAssertEqualObjects([descriptor getEnumNameForIndex:2], @"TestEnumObjCNameCollision_Bar");
   textFormatName = [descriptor getEnumTextFormatNameForIndex:2];
   XCTAssertEqualObjects(textFormatName, @"BAR");
   XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
   XCTAssertEqual(value, 2);

   XCTAssertEqualObjects([descriptor getEnumNameForIndex:3], @"TestEnumObjCNameCollision_Mumble");
   textFormatName = [descriptor getEnumTextFormatNameForIndex:3];
   XCTAssertEqualObjects(textFormatName, @"mumble");
   XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
   XCTAssertEqual(value, 2);

   XCTAssertEqualObjects([descriptor getEnumNameForIndex:4], @"TestEnumObjCNameCollision_Mumble");
   textFormatName = [descriptor getEnumTextFormatNameForIndex:4];
   XCTAssertEqualObjects(textFormatName, @"MUMBLE");
   XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
   XCTAssertEqual(value, 2);
 }

 - (void)testEnumValueValidator {
   GPBDescriptor *descriptor = [TestAllTypes descriptor];
   GPBFieldDescriptor *fieldDescriptor =
       [descriptor fieldWithName:@"optionalNestedEnum"];

   // Valid values
   XCTAssertTrue([fieldDescriptor isValidEnumValue:1]);
   XCTAssertTrue([fieldDescriptor isValidEnumValue:2]);
   XCTAssertTrue([fieldDescriptor isValidEnumValue:3]);
   XCTAssertTrue([fieldDescriptor isValidEnumValue:-1]);

   // Invalid values
   XCTAssertFalse([fieldDescriptor isValidEnumValue:4]);
   XCTAssertFalse([fieldDescriptor isValidEnumValue:0]);
   XCTAssertFalse([fieldDescriptor isValidEnumValue:-2]);
 }

 - (void)testOneofDescriptor {
   GPBDescriptor *descriptor = [TestOneof2 descriptor];

   GPBFieldDescriptor *fooStringField =
       [descriptor fieldWithNumber:TestOneof2_FieldNumber_FooString];
   XCTAssertNotNil(fooStringField);
   GPBFieldDescriptor *barStringField =
       [descriptor fieldWithNumber:TestOneof2_FieldNumber_BarString];
   XCTAssertNotNil(barStringField);

   // Check the oneofs to have what is expected but not other onesofs

   GPBOneofDescriptor *oneofFoo = [descriptor oneofWithName:@"foo"];
   XCTAssertNotNil(oneofFoo);
   XCTAssertNotNil([oneofFoo fieldWithName:@"fooString"]);
   XCTAssertNil([oneofFoo fieldWithName:@"barString"]);

   GPBOneofDescriptor *oneofBar = [descriptor oneofWithName:@"bar"];
   XCTAssertNotNil(oneofBar);
   XCTAssertNil([oneofBar fieldWithName:@"fooString"]);
   XCTAssertNotNil([oneofBar fieldWithName:@"barString"]);

   // Pointer comparisons against lookups from message.

   XCTAssertEqual([oneofFoo fieldWithNumber:TestOneof2_FieldNumber_FooString],
                  fooStringField);
   XCTAssertEqual([oneofFoo fieldWithName:@"fooString"], fooStringField);

   XCTAssertEqual([oneofBar fieldWithNumber:TestOneof2_FieldNumber_BarString],
                  barStringField);
   XCTAssertEqual([oneofBar fieldWithName:@"barString"], barStringField);

   // Unknown oneof not found.

   XCTAssertNil([descriptor oneofWithName:@"mumble"]);
   XCTAssertNil([descriptor oneofWithName:@"Foo"]);

   // Unknown oneof item.

   XCTAssertNil([oneofFoo fieldWithName:@"mumble"]);
   XCTAssertNil([oneofFoo fieldWithNumber:666]);

   // Field exists, but not in this oneof.

   XCTAssertNil([oneofFoo fieldWithName:@"barString"]);
   XCTAssertNil([oneofFoo fieldWithNumber:TestOneof2_FieldNumber_BarString]);
   XCTAssertNil([oneofBar fieldWithName:@"fooString"]);
   XCTAssertNil([oneofBar fieldWithNumber:TestOneof2_FieldNumber_FooString]);

   // Check pointers back to the enclosing oneofs.
   // (pointer comparisons)
   XCTAssertEqual(fooStringField.containingOneof, oneofFoo);
   XCTAssertEqual(barStringField.containingOneof, oneofBar);
   GPBFieldDescriptor *bazString =
       [descriptor fieldWithNumber:TestOneof2_FieldNumber_BazString];
   XCTAssertNotNil(bazString);
   XCTAssertNil(bazString.containingOneof);
 }

 - (void)testExtensiondDescriptor {
   Class msgClass = [TestAllExtensions class];
   Class packedMsgClass = [TestPackedExtensions class];

   // Int

   GPBExtensionDescriptor *descriptor = [UnittestRoot optionalInt32Extension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertEqualObjects(descriptor.defaultValue, @0);
   XCTAssertNil(descriptor.enumDescriptor);

   descriptor = [UnittestRoot defaultInt32Extension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertEqualObjects(descriptor.defaultValue, @41);
   XCTAssertNil(descriptor.enumDescriptor);

   // Enum

   descriptor = [UnittestRoot optionalNestedEnumExtension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertEqual(descriptor.defaultValue, @1);
   XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"TestAllTypes_NestedEnum");

   descriptor = [UnittestRoot defaultNestedEnumExtension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertEqual(descriptor.defaultValue, @2);
   XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"TestAllTypes_NestedEnum");

   // Message

   descriptor = [UnittestRoot optionalNestedMessageExtension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertNil(descriptor.defaultValue);
   XCTAssertNil(descriptor.enumDescriptor);

   // Repeated Int

   descriptor = [UnittestRoot repeatedInt32Extension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertNil(descriptor.defaultValue);
   XCTAssertNil(descriptor.enumDescriptor);

   descriptor = [UnittestRoot packedInt32Extension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, packedMsgClass);  // ptr equality
   XCTAssertTrue(descriptor.isPackable);
   XCTAssertNil(descriptor.defaultValue);
   XCTAssertNil(descriptor.enumDescriptor);

   // Repeated Enum

   descriptor = [UnittestRoot repeatedNestedEnumExtension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertNil(descriptor.defaultValue);
   XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"TestAllTypes_NestedEnum");

   descriptor = [UnittestRoot packedEnumExtension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, packedMsgClass);  // ptr equality
   XCTAssertTrue(descriptor.isPackable);
   XCTAssertNil(descriptor.defaultValue);
   XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"ForeignEnum");

   // Repeated Message

   descriptor = [UnittestRoot repeatedNestedMessageExtension];
   XCTAssertNotNil(descriptor);
   XCTAssertEqual(descriptor.containingMessageClass, msgClass);  // ptr equality
   XCTAssertFalse(descriptor.isPackable);
   XCTAssertNil(descriptor.defaultValue);
   XCTAssertNil(descriptor.enumDescriptor);

   // Compare (used internally for serialization).

   GPBExtensionDescriptor *ext1 = [UnittestRoot optionalInt32Extension];
   XCTAssertEqual(ext1.fieldNumber, 1u);
   GPBExtensionDescriptor *ext2 = [UnittestRoot optionalInt64Extension];
   XCTAssertEqual(ext2.fieldNumber, 2u);

   XCTAssertEqual([ext1 compareByFieldNumber:ext2], NSOrderedAscending);
   XCTAssertEqual([ext2 compareByFieldNumber:ext1], NSOrderedDescending);
   XCTAssertEqual([ext1 compareByFieldNumber:ext1], NSOrderedSame);
 }

 @end
	// 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 "GPBDescriptor_PackagePrivate.h"
	#import "google/protobuf/Unittest.pbobjc.h"
	#import "google/protobuf/UnittestObjc.pbobjc.h"
	#import "google/protobuf/Descriptor.pbobjc.h"

	@interface DescriptorTests : GPBTestCase
	@end

	@implementation DescriptorTests

	- (void)testDescriptor_containingType {
	GPBDescriptor *testAllTypesDesc = [TestAllTypes descriptor];
	GPBDescriptor *nestedMessageDesc = [TestAllTypes_NestedMessage descriptor];
	XCTAssertNil(testAllTypesDesc.containingType);
	XCTAssertNotNil(nestedMessageDesc.containingType);
	XCTAssertEqual(nestedMessageDesc.containingType, testAllTypesDesc); // Ptr comparison
	}

	- (void)testDescriptor_fullName {
	GPBDescriptor *testAllTypesDesc = [TestAllTypes descriptor];
	XCTAssertEqualObjects(testAllTypesDesc.fullName, @"protobuf_unittest.TestAllTypes");
	GPBDescriptor *nestedMessageDesc = [TestAllTypes_NestedMessage descriptor];
	XCTAssertEqualObjects(nestedMessageDesc.fullName, @"protobuf_unittest.TestAllTypes.NestedMessage");

	// Prefixes removed.
	GPBDescriptor *descDesc = [GPBDescriptorProto descriptor];
	XCTAssertEqualObjects(descDesc.fullName, @"google.protobuf.DescriptorProto");
	GPBDescriptor *descExtRngDesc = [GPBDescriptorProto_ExtensionRange descriptor];
	XCTAssertEqualObjects(descExtRngDesc.fullName, @"google.protobuf.DescriptorProto.ExtensionRange");

	// Things that get "_Class" added.
	GPBDescriptor *pointDesc = [Point_Class descriptor];
	XCTAssertEqualObjects(pointDesc.fullName, @"protobuf_unittest.Point");
	GPBDescriptor *pointRectDesc = [Point_Rect descriptor];
	XCTAssertEqualObjects(pointRectDesc.fullName, @"protobuf_unittest.Point.Rect");
	}

	- (void)testFieldDescriptor {
	GPBDescriptor *descriptor = [TestAllTypes descriptor];

	// Nested Enum
	GPBFieldDescriptor *fieldDescriptorWithName =
	[descriptor fieldWithName:@"optionalNestedEnum"];
	XCTAssertNotNil(fieldDescriptorWithName);
	GPBFieldDescriptor *fieldDescriptorWithNumber =
	[descriptor fieldWithNumber:21];
	XCTAssertNotNil(fieldDescriptorWithNumber);
	XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
	XCTAssertNotNil(fieldDescriptorWithNumber.enumDescriptor);
	XCTAssertEqualObjects(fieldDescriptorWithNumber.enumDescriptor.name,
	@"TestAllTypes_NestedEnum");
	XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
	XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeEnum);

	// Foreign Enum
	fieldDescriptorWithName = [descriptor fieldWithName:@"optionalForeignEnum"];
	XCTAssertNotNil(fieldDescriptorWithName);
	fieldDescriptorWithNumber = [descriptor fieldWithNumber:22];
	XCTAssertNotNil(fieldDescriptorWithNumber);
	XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
	XCTAssertNotNil(fieldDescriptorWithNumber.enumDescriptor);
	XCTAssertEqualObjects(fieldDescriptorWithNumber.enumDescriptor.name,
	@"ForeignEnum");
	XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
	XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeEnum);

	// Import Enum
	fieldDescriptorWithName = [descriptor fieldWithName:@"optionalImportEnum"];
	XCTAssertNotNil(fieldDescriptorWithName);
	fieldDescriptorWithNumber = [descriptor fieldWithNumber:23];
	XCTAssertNotNil(fieldDescriptorWithNumber);
	XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
	XCTAssertNotNil(fieldDescriptorWithNumber.enumDescriptor);
	XCTAssertEqualObjects(fieldDescriptorWithNumber.enumDescriptor.name,
	@"ImportEnum");
	XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
	XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeEnum);

	// Nested Message
	fieldDescriptorWithName = [descriptor fieldWithName:@"optionalNestedMessage"];
	XCTAssertNotNil(fieldDescriptorWithName);
	fieldDescriptorWithNumber = [descriptor fieldWithNumber:18];
	XCTAssertNotNil(fieldDescriptorWithNumber);
	XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
	XCTAssertNil(fieldDescriptorWithNumber.enumDescriptor);
	XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
	XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeMessage);

	// Foreign Message
	fieldDescriptorWithName =
	[descriptor fieldWithName:@"optionalForeignMessage"];
	XCTAssertNotNil(fieldDescriptorWithName);
	fieldDescriptorWithNumber = [descriptor fieldWithNumber:19];
	XCTAssertNotNil(fieldDescriptorWithNumber);
	XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
	XCTAssertNil(fieldDescriptorWithNumber.enumDescriptor);
	XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
	XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeMessage);

	// Import Message
	fieldDescriptorWithName = [descriptor fieldWithName:@"optionalImportMessage"];
	XCTAssertNotNil(fieldDescriptorWithName);
	fieldDescriptorWithNumber = [descriptor fieldWithNumber:20];
	XCTAssertNotNil(fieldDescriptorWithNumber);
	XCTAssertEqual(fieldDescriptorWithName, fieldDescriptorWithNumber);
	XCTAssertNil(fieldDescriptorWithNumber.enumDescriptor);
	XCTAssertEqual(fieldDescriptorWithName.number, fieldDescriptorWithNumber.number);
	XCTAssertEqual(fieldDescriptorWithName.dataType, GPBDataTypeMessage);

	// Some failed lookups.
	XCTAssertNil([descriptor fieldWithName:@"NOT THERE"]);
	XCTAssertNil([descriptor fieldWithNumber:9876543]);
	}

	- (void)testEnumDescriptor {
	GPBEnumDescriptor *descriptor = TestAllTypes_NestedEnum_EnumDescriptor();

	NSString *enumName = [descriptor enumNameForValue:1];
	XCTAssertNotNil(enumName);
	int32_t value;
	XCTAssertTrue(
	[descriptor getValue:&value forEnumName:@"TestAllTypes_NestedEnum_Foo"]);
	XCTAssertTrue(
	[descriptor getValue:NULL forEnumName:@"TestAllTypes_NestedEnum_Foo"]);
	XCTAssertEqual(value, TestAllTypes_NestedEnum_Foo);

	enumName = [descriptor enumNameForValue:2];
	XCTAssertNotNil(enumName);
	XCTAssertTrue(
	[descriptor getValue:&value forEnumName:@"TestAllTypes_NestedEnum_Bar"]);
	XCTAssertEqual(value, TestAllTypes_NestedEnum_Bar);

	enumName = [descriptor enumNameForValue:3];
	XCTAssertNotNil(enumName);
	XCTAssertTrue(
	[descriptor getValue:&value forEnumName:@"TestAllTypes_NestedEnum_Baz"]);
	XCTAssertEqual(value, TestAllTypes_NestedEnum_Baz);

	// TextFormat
	enumName = [descriptor textFormatNameForValue:1];
	XCTAssertNotNil(enumName);
	XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:@"FOO"]);
	XCTAssertEqual(value, TestAllTypes_NestedEnum_Foo);
	XCTAssertNil([descriptor textFormatNameForValue:99999]);

	// Bad values
	enumName = [descriptor enumNameForValue:0];
	XCTAssertNil(enumName);
	XCTAssertFalse([descriptor getValue:&value forEnumName:@"Unknown"]);
	XCTAssertFalse([descriptor getValue:NULL forEnumName:@"Unknown"]);
	XCTAssertFalse([descriptor getValue:&value
	forEnumName:@"TestAllTypes_NestedEnum_Unknown"]);
	XCTAssertFalse([descriptor getValue:NULL
	forEnumName:@"TestAllTypes_NestedEnum_Unknown"]);
	XCTAssertFalse([descriptor getValue:NULL forEnumTextFormatName:@"Unknown"]);
	XCTAssertFalse([descriptor getValue:&value forEnumTextFormatName:@"Unknown"]);
	}

	- (void)testEnumDescriptorIntrospection {
	GPBEnumDescriptor *descriptor = TestAllTypes_NestedEnum_EnumDescriptor();

	XCTAssertEqual(descriptor.enumNameCount, 4U);
	XCTAssertEqualObjects([descriptor getEnumNameForIndex:0],
	@"TestAllTypes_NestedEnum_Foo");
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:0], @"FOO");
	XCTAssertEqualObjects([descriptor getEnumNameForIndex:1],
	@"TestAllTypes_NestedEnum_Bar");
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:1], @"BAR");
	XCTAssertEqualObjects([descriptor getEnumNameForIndex:2],
	@"TestAllTypes_NestedEnum_Baz");
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:2], @"BAZ");
	XCTAssertEqualObjects([descriptor getEnumNameForIndex:3],
	@"TestAllTypes_NestedEnum_Neg");
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:3], @"NEG");
	}

	- (void)testEnumDescriptorIntrospectionWithAlias {
	GPBEnumDescriptor *descriptor = TestEnumWithDupValue_EnumDescriptor();
	NSString *enumName;
	int32_t value;

	XCTAssertEqual(descriptor.enumNameCount, 5U);

	enumName = [descriptor getEnumNameForIndex:0];
	XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Foo1");
	XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
	XCTAssertEqual(value, 1);
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:0], @"FOO1");

	enumName = [descriptor getEnumNameForIndex:1];
	XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Bar1");
	XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
	XCTAssertEqual(value, 2);
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:1], @"BAR1");

	enumName = [descriptor getEnumNameForIndex:2];
	XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Baz");
	XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
	XCTAssertEqual(value, 3);
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:2], @"BAZ");

	enumName = [descriptor getEnumNameForIndex:3];
	XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Foo2");
	XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
	XCTAssertEqual(value, 1);
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:3], @"FOO2");

	enumName = [descriptor getEnumNameForIndex:4];
	XCTAssertEqualObjects(enumName, @"TestEnumWithDupValue_Bar2");
	XCTAssertTrue([descriptor getValue:&value forEnumName:enumName]);
	XCTAssertEqual(value, 2);
	XCTAssertEqualObjects([descriptor getEnumTextFormatNameForIndex:4], @"BAR2");
	}

	- (void)testEnumAliasNameCollisions {
	GPBEnumDescriptor *descriptor = TestEnumObjCNameCollision_EnumDescriptor();
	NSString *textFormatName;
	int32_t value;

	XCTAssertEqual(descriptor.enumNameCount, 5U);

	XCTAssertEqualObjects([descriptor getEnumNameForIndex:0], @"TestEnumObjCNameCollision_Foo");
	textFormatName = [descriptor getEnumTextFormatNameForIndex:0];
	XCTAssertEqualObjects(textFormatName, @"FOO");
	XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
	XCTAssertEqual(value, 1);

	XCTAssertEqualObjects([descriptor getEnumNameForIndex:1], @"TestEnumObjCNameCollision_Foo");
	textFormatName = [descriptor getEnumTextFormatNameForIndex:1];
	XCTAssertEqualObjects(textFormatName, @"foo");
	XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
	XCTAssertEqual(value, 1);

	XCTAssertEqualObjects([descriptor getEnumNameForIndex:2], @"TestEnumObjCNameCollision_Bar");
	textFormatName = [descriptor getEnumTextFormatNameForIndex:2];
	XCTAssertEqualObjects(textFormatName, @"BAR");
	XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
	XCTAssertEqual(value, 2);

	XCTAssertEqualObjects([descriptor getEnumNameForIndex:3], @"TestEnumObjCNameCollision_Mumble");
	textFormatName = [descriptor getEnumTextFormatNameForIndex:3];
	XCTAssertEqualObjects(textFormatName, @"mumble");
	XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
	XCTAssertEqual(value, 2);

	XCTAssertEqualObjects([descriptor getEnumNameForIndex:4], @"TestEnumObjCNameCollision_Mumble");
	textFormatName = [descriptor getEnumTextFormatNameForIndex:4];
	XCTAssertEqualObjects(textFormatName, @"MUMBLE");
	XCTAssertTrue([descriptor getValue:&value forEnumTextFormatName:textFormatName]);
	XCTAssertEqual(value, 2);
	}

	- (void)testEnumValueValidator {
	GPBDescriptor *descriptor = [TestAllTypes descriptor];
	GPBFieldDescriptor *fieldDescriptor =
	[descriptor fieldWithName:@"optionalNestedEnum"];

	// Valid values
	XCTAssertTrue([fieldDescriptor isValidEnumValue:1]);
	XCTAssertTrue([fieldDescriptor isValidEnumValue:2]);
	XCTAssertTrue([fieldDescriptor isValidEnumValue:3]);
	XCTAssertTrue([fieldDescriptor isValidEnumValue:-1]);

	// Invalid values
	XCTAssertFalse([fieldDescriptor isValidEnumValue:4]);
	XCTAssertFalse([fieldDescriptor isValidEnumValue:0]);
	XCTAssertFalse([fieldDescriptor isValidEnumValue:-2]);
	}

	- (void)testOneofDescriptor {
	GPBDescriptor *descriptor = [TestOneof2 descriptor];

	GPBFieldDescriptor *fooStringField =
	[descriptor fieldWithNumber:TestOneof2_FieldNumber_FooString];
	XCTAssertNotNil(fooStringField);
	GPBFieldDescriptor *barStringField =
	[descriptor fieldWithNumber:TestOneof2_FieldNumber_BarString];
	XCTAssertNotNil(barStringField);

	// Check the oneofs to have what is expected but not other onesofs

	GPBOneofDescriptor *oneofFoo = [descriptor oneofWithName:@"foo"];
	XCTAssertNotNil(oneofFoo);
	XCTAssertNotNil([oneofFoo fieldWithName:@"fooString"]);
	XCTAssertNil([oneofFoo fieldWithName:@"barString"]);

	GPBOneofDescriptor *oneofBar = [descriptor oneofWithName:@"bar"];
	XCTAssertNotNil(oneofBar);
	XCTAssertNil([oneofBar fieldWithName:@"fooString"]);
	XCTAssertNotNil([oneofBar fieldWithName:@"barString"]);

	// Pointer comparisons against lookups from message.

	XCTAssertEqual([oneofFoo fieldWithNumber:TestOneof2_FieldNumber_FooString],
	fooStringField);
	XCTAssertEqual([oneofFoo fieldWithName:@"fooString"], fooStringField);

	XCTAssertEqual([oneofBar fieldWithNumber:TestOneof2_FieldNumber_BarString],
	barStringField);
	XCTAssertEqual([oneofBar fieldWithName:@"barString"], barStringField);

	// Unknown oneof not found.

	XCTAssertNil([descriptor oneofWithName:@"mumble"]);
	XCTAssertNil([descriptor oneofWithName:@"Foo"]);

	// Unknown oneof item.

	XCTAssertNil([oneofFoo fieldWithName:@"mumble"]);
	XCTAssertNil([oneofFoo fieldWithNumber:666]);

	// Field exists, but not in this oneof.

	XCTAssertNil([oneofFoo fieldWithName:@"barString"]);
	XCTAssertNil([oneofFoo fieldWithNumber:TestOneof2_FieldNumber_BarString]);
	XCTAssertNil([oneofBar fieldWithName:@"fooString"]);
	XCTAssertNil([oneofBar fieldWithNumber:TestOneof2_FieldNumber_FooString]);

	// Check pointers back to the enclosing oneofs.
	// (pointer comparisons)
	XCTAssertEqual(fooStringField.containingOneof, oneofFoo);
	XCTAssertEqual(barStringField.containingOneof, oneofBar);
	GPBFieldDescriptor *bazString =
	[descriptor fieldWithNumber:TestOneof2_FieldNumber_BazString];
	XCTAssertNotNil(bazString);
	XCTAssertNil(bazString.containingOneof);
	}

	- (void)testExtensiondDescriptor {
	Class msgClass = [TestAllExtensions class];
	Class packedMsgClass = [TestPackedExtensions class];

	// Int

	GPBExtensionDescriptor *descriptor = [UnittestRoot optionalInt32Extension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertEqualObjects(descriptor.defaultValue, @0);
	XCTAssertNil(descriptor.enumDescriptor);

	descriptor = [UnittestRoot defaultInt32Extension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertEqualObjects(descriptor.defaultValue, @41);
	XCTAssertNil(descriptor.enumDescriptor);

	// Enum

	descriptor = [UnittestRoot optionalNestedEnumExtension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertEqual(descriptor.defaultValue, @1);
	XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"TestAllTypes_NestedEnum");

	descriptor = [UnittestRoot defaultNestedEnumExtension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertEqual(descriptor.defaultValue, @2);
	XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"TestAllTypes_NestedEnum");

	// Message

	descriptor = [UnittestRoot optionalNestedMessageExtension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertNil(descriptor.defaultValue);
	XCTAssertNil(descriptor.enumDescriptor);

	// Repeated Int

	descriptor = [UnittestRoot repeatedInt32Extension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertNil(descriptor.defaultValue);
	XCTAssertNil(descriptor.enumDescriptor);

	descriptor = [UnittestRoot packedInt32Extension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, packedMsgClass); // ptr equality
	XCTAssertTrue(descriptor.isPackable);
	XCTAssertNil(descriptor.defaultValue);
	XCTAssertNil(descriptor.enumDescriptor);

	// Repeated Enum

	descriptor = [UnittestRoot repeatedNestedEnumExtension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertNil(descriptor.defaultValue);
	XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"TestAllTypes_NestedEnum");

	descriptor = [UnittestRoot packedEnumExtension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, packedMsgClass); // ptr equality
	XCTAssertTrue(descriptor.isPackable);
	XCTAssertNil(descriptor.defaultValue);
	XCTAssertEqualObjects(descriptor.enumDescriptor.name, @"ForeignEnum");

	// Repeated Message

	descriptor = [UnittestRoot repeatedNestedMessageExtension];
	XCTAssertNotNil(descriptor);
	XCTAssertEqual(descriptor.containingMessageClass, msgClass); // ptr equality
	XCTAssertFalse(descriptor.isPackable);
	XCTAssertNil(descriptor.defaultValue);
	XCTAssertNil(descriptor.enumDescriptor);

	// Compare (used internally for serialization).

	GPBExtensionDescriptor *ext1 = [UnittestRoot optionalInt32Extension];
	XCTAssertEqual(ext1.fieldNumber, 1u);
	GPBExtensionDescriptor *ext2 = [UnittestRoot optionalInt64Extension];
	XCTAssertEqual(ext2.fieldNumber, 2u);

	XCTAssertEqual([ext1 compareByFieldNumber:ext2], NSOrderedAscending);
	XCTAssertEqual([ext2 compareByFieldNumber:ext1], NSOrderedDescending);
	XCTAssertEqual([ext1 compareByFieldNumber:ext1], NSOrderedSame);
	}

	@end