Update test protos copied from C++ protobuf (#1079)

diff --git a/protoc_plugin/test/constructor_args_test.dart b/protoc_plugin/test/constructor_args_test.dart
index b5859d9..8ff8ba9 100644
--- a/protoc_plugin/test/constructor_args_test.dart
+++ b/protoc_plugin/test/constructor_args_test.dart
@@ -44,7 +44,7 @@
         optionalBool: true,
         optionalString: '115',
         optionalBytes: '116'.codeUnits,
-        optionalGroup: TestAllTypes_OptionalGroup(a: 117),
+        optionalgroup: TestAllTypes_OptionalGroup(a: 117),
         optionalNestedMessage: TestAllTypes_NestedMessage(bb: 118),
         optionalForeignMessage: ForeignMessage(c: 119),
         optionalImportMessage: ImportMessage(d: 120),
@@ -68,7 +68,7 @@
         repeatedBool: [true, false],
         repeatedString: ['215', '315'],
         repeatedBytes: ['216'.codeUnits, '316'.codeUnits],
-        repeatedGroup: [
+        repeatedgroup: [
           TestAllTypes_RepeatedGroup(a: 217),
           TestAllTypes_RepeatedGroup(a: 317),
         ],
diff --git a/protoc_plugin/test/descriptor_test.dart b/protoc_plugin/test/descriptor_test.dart
index df60d98..cca2c75 100644
--- a/protoc_plugin/test/descriptor_test.dart
+++ b/protoc_plugin/test/descriptor_test.dart
@@ -24,6 +24,8 @@
       'FOREIGN_FOO',
       'FOREIGN_BAR',
       'FOREIGN_BAZ',
+      'FOREIGN_BAX',
+      'FOREIGN_LARGE',
     ]);
   });
   test('Can decode service descriptor', () {
diff --git a/protoc_plugin/test/extension_test.dart b/protoc_plugin/test/extension_test.dart
index 399cfb0..ad45a93 100644
--- a/protoc_plugin/test/extension_test.dart
+++ b/protoc_plugin/test/extension_test.dart
@@ -118,27 +118,18 @@
   });
 
   test('can merge extension', () {
-    final nestedMessage = TestAllTypes_NestedMessage()..i = 42;
     final mergeSource =
-        TestAllExtensions()..setExtension(
-          Unittest.optionalNestedMessageExtension,
-          nestedMessage,
-        );
+        TestAllExtensions()..addExtension(Unittest.repeatedInt32Extension, 123);
 
-    final nestedMessage2 = TestAllTypes_NestedMessage()..bb = 43;
     final mergeDest =
-        TestAllExtensions()..setExtension(
-          Unittest.optionalNestedMessageExtension,
-          nestedMessage2,
-        );
+        TestAllExtensions()..addExtension(Unittest.repeatedInt32Extension, 456);
 
     final result =
         TestAllExtensions()
           ..mergeFromMessage(mergeSource)
           ..mergeFromMessage(mergeDest);
 
-    expect(result.getExtension(Unittest.optionalNestedMessageExtension).i, 42);
-    expect(result.getExtension(Unittest.optionalNestedMessageExtension).bb, 43);
+    expect(result.getExtension(Unittest.repeatedInt32Extension), [123, 456]);
   });
 
   test("throws if field number isn't allowed for extension", () {
@@ -148,7 +139,7 @@
         message.setExtension(Unittest.optionalInt32Extension, 0);
       },
       throwsArgError(
-        'Extension optionalInt32Extension not legal for message protobuf_unittest.TestAllTypes',
+        'Extension optionalInt32Extension not legal for message proto2_unittest.TestAllTypes',
       ),
     );
 
@@ -157,7 +148,7 @@
         message.getExtension(Unittest.optionalInt32Extension);
       },
       throwsArgError(
-        'Extension optionalInt32Extension not legal for message protobuf_unittest.TestAllTypes',
+        'Extension optionalInt32Extension not legal for message proto2_unittest.TestAllTypes',
       ),
     );
   });
@@ -169,7 +160,7 @@
         message.setExtension(Unittest.optionalInt32Extension, 'hello');
       },
       throwsArgError(
-        'Illegal to set field optionalInt32Extension (1) of protobuf_unittest.TestAllExtensions'
+        'Illegal to set field optionalInt32Extension (1) of proto2_unittest.TestAllExtensions'
         ' to value (hello): not type int',
       ),
     );
@@ -182,7 +173,7 @@
         message.setExtension(Unittest.optionalInt64Extension, 123);
       },
       throwsArgError(
-        'Illegal to set field optionalInt64Extension (2) of protobuf_unittest.TestAllExtensions'
+        'Illegal to set field optionalInt64Extension (2) of proto2_unittest.TestAllExtensions'
         ' to value (123): not Int64',
       ),
     );
@@ -198,7 +189,7 @@
       },
       throwsArgError(
         'Illegal to set field optionalNestedMessageExtension (18)'
-        ' of protobuf_unittest.TestAllExtensions to value (123): not a GeneratedMessage',
+        ' of proto2_unittest.TestAllExtensions to value (123): not a GeneratedMessage',
       ),
     );
 
@@ -221,7 +212,7 @@
       },
       throwsArgError(
         'Illegal to set field optionalNestedEnumExtension (21)'
-        ' of protobuf_unittest.TestAllExtensions to value (123): not type ProtobufEnum',
+        ' of proto2_unittest.TestAllExtensions to value (123): not type ProtobufEnum',
       ),
     );
 
@@ -272,7 +263,7 @@
           ..addExtension(Unittest.repeatedStringExtension, 'world')
           ..setExtension(
             Unittest.optionalNestedMessageExtension,
-            TestAllTypes_NestedMessage()..i = 42,
+            TestAllTypes_NestedMessage()..bb = 42,
           )
           ..setExtension(
             Unittest.optionalNestedEnumExtension,
@@ -282,7 +273,7 @@
     final expected =
         '[optionalInt32Extension]: 1\n'
         '[optionalNestedMessageExtension]: {\n'
-        '  i: 42\n'
+        '  bb: 42\n'
         '}\n'
         '[optionalNestedEnumExtension]: BAR\n'
         '[repeatedStringExtension]: hello\n'
@@ -438,8 +429,8 @@
   test('ExtensionRegistry.reparseMessage will throw on malformed buffers', () {
     final r = ExtensionRegistry();
     Unittest.registerAllExtensions(r);
-    final r2 = ExtensionRegistry();
 
+    final r2 = ExtensionRegistry();
     Extend_unittest.registerAllExtensions(r2);
 
     // The message encoded in this buffer has an encoding error in the
@@ -709,7 +700,7 @@
     },
   );
 
-  test('consistent hashcode for reparsed messages with extensions', () {
+  test('consistent hashCode for reparsed messages with extensions', () {
     final r = ExtensionRegistry()..add(Extend_unittest.outer);
     final m =
         TestAllExtensions()..setExtension(
diff --git a/protoc_plugin/test/generated_message_test.dart b/protoc_plugin/test/generated_message_test.dart
index 1f62b9e..19f96bb 100644
--- a/protoc_plugin/test/generated_message_test.dart
+++ b/protoc_plugin/test/generated_message_test.dart
@@ -315,6 +315,7 @@
       TestAllTypes_NestedEnum.FOO,
       TestAllTypes_NestedEnum.BAR,
       TestAllTypes_NestedEnum.BAZ,
+      TestAllTypes_NestedEnum.NEG,
     ]);
     expect(TestAllTypes_NestedEnum.FOO.value, 1);
     expect(TestAllTypes_NestedEnum.BAR.value, 2);
@@ -897,9 +898,8 @@
   //   fields are immutable and can be shared.
   // value2.optionalBytes.add(123);
 
-  value2.optionalGroup.a += 1;
+  value2.optionalgroup.a += 1;
   value2.optionalNestedMessage.bb += 1;
-  value2.optionalNestedMessage.i += 1;
   value2.optionalImportMessage.d += 1;
   value2.optionalNestedEnum = TestAllTypes_NestedEnum.BAR;
   value2.optionalForeignEnum = ForeignEnum.FOREIGN_BAR;
@@ -967,7 +967,7 @@
   // Same as `testCopy`, don't test `bytes` fields.
   // value2.getExtension(Unittest.optionalBytesExtension).add(987);
 
-  value2.getExtension(Unittest.optionalGroupExtension).a += 1;
+  value2.getExtension(Unittest.optionalgroupExtension).a += 1;
   value2.getExtension(Unittest.optionalNestedMessageExtension).bb += 1;
   value2.getExtension(Unittest.optionalForeignMessageExtension).c += 1;
   value2.getExtension(Unittest.optionalImportMessageExtension).d += 1;
@@ -1002,7 +1002,7 @@
   value2.getExtension(Unittest.repeatedStringExtension).add("hi 4");
   value2.getExtension(Unittest.repeatedBytesExtension).add(<int>[1, 2, 3]);
   value2
-      .getExtension(Unittest.repeatedGroupExtension)
+      .getExtension(Unittest.repeatedgroupExtension)
       .add(RepeatedGroup_extension());
   value2
       .getExtension(Unittest.repeatedNestedMessageExtension)
diff --git a/protoc_plugin/test/message_test.dart b/protoc_plugin/test/message_test.dart
index cfbbe10..17095e8 100644
--- a/protoc_plugin/test/message_test.dart
+++ b/protoc_plugin/test/message_test.dart
@@ -27,7 +27,7 @@
           ..optionalInt32 = 1
           ..optionalString = 'foo'
           ..optionalForeignMessage = ForeignMessage()
-          ..optionalNestedMessage = (TestAllTypes_NestedMessage()..i = 42)
+          ..optionalNestedMessage = (TestAllTypes_NestedMessage()..bb = 42)
           ..repeatedString.add('bar');
 
     final mergeDest =
@@ -45,7 +45,6 @@
 optionalString: baz
 optionalNestedMessage: {
   bb: 43
-  i: 42
 }
 optionalForeignMessage: {
   c: 3
diff --git a/protoc_plugin/test/omit_message_names_test.dart b/protoc_plugin/test/omit_message_names_test.dart
index 0751d5c..e463222 100644
--- a/protoc_plugin/test/omit_message_names_test.dart
+++ b/protoc_plugin/test/omit_message_names_test.dart
@@ -15,7 +15,7 @@
       TestAllTypes_NestedMessage().info_.qualifiedMessageName,
       const bool.fromEnvironment('protobuf.omit_message_names')
           ? ''
-          : 'protobuf_unittest.TestAllTypes.NestedMessage',
+          : 'proto2_unittest.TestAllTypes.NestedMessage',
     );
     expect(constant(), 'SHOULD_BE_PRESENT');
   });
diff --git a/protoc_plugin/test/proto3_json_test.dart b/protoc_plugin/test/proto3_json_test.dart
index e421bbe..5654dc9 100644
--- a/protoc_plugin/test/proto3_json_test.dart
+++ b/protoc_plugin/test/proto3_json_test.dart
@@ -313,7 +313,7 @@
           TestAllTypes()..optionalFixed64 = Int64(100),
         ).toProto3Json(typeRegistry: TypeRegistry([TestAllTypes()])),
         {
-          '@type': 'type.googleapis.com/protobuf_unittest.TestAllTypes',
+          '@type': 'type.googleapis.com/proto2_unittest.TestAllTypes',
           'optionalFixed64': '100',
         },
       );
@@ -920,8 +920,7 @@
       expect(
         () =>
             Any()..mergeFromProto3Json({
-              '@type':
-                  'type.googleapis.com/protobuf_unittest.SparseEnumMessage',
+              '@type': 'type.googleapis.com/proto2_unittest.SparseEnumMessage',
               'sparseEnum': 'SPARSEB',
             }, typeRegistry: TypeRegistry([SparseEnumMessage()])),
         parseFailure(['sparseEnum']),
@@ -929,7 +928,7 @@
       expect(
         Any()..mergeFromProto3Json(
           {
-            '@type': 'type.googleapis.com/protobuf_unittest.SparseEnumMessage',
+            '@type': 'type.googleapis.com/proto2_unittest.SparseEnumMessage',
             'sparseEnum': 'SPARSEB',
           },
           typeRegistry: TypeRegistry([SparseEnumMessage()]),
@@ -1106,7 +1105,7 @@
     test('Any', () {
       final m1 =
           Any()..mergeFromProto3Json({
-            '@type': 'type.googleapis.com/protobuf_unittest.TestAllTypes',
+            '@type': 'type.googleapis.com/proto2_unittest.TestAllTypes',
             'optionalFixed64': '100',
           }, typeRegistry: TypeRegistry([TestAllTypes()]));
 
diff --git a/protoc_plugin/test/protos/extend_unittest.proto b/protoc_plugin/test/protos/extend_unittest.proto
index f1d7d50..cbff720 100644
--- a/protoc_plugin/test/protos/extend_unittest.proto
+++ b/protoc_plugin/test/protos/extend_unittest.proto
@@ -39,7 +39,7 @@
   optional string inner_most_extension_string = 2;
 }
 
-extend protobuf_unittest.TestAllExtensions {
+extend proto2_unittest.TestAllExtensions {
   optional Outer outer = 104;
 }
 
diff --git a/protoc_plugin/test/protos/google/protobuf/unittest.proto b/protoc_plugin/test/protos/google/protobuf/unittest.proto
index 129d24b..185c891 100644
--- a/protoc_plugin/test/protos/google/protobuf/unittest.proto
+++ b/protoc_plugin/test/protos/google/protobuf/unittest.proto
@@ -1,59 +1,44 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
 //
-// 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.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
 
 // Author: kenton@google.com (Kenton Varda)
 //  Based on original Protocol Buffers design by
 //  Sanjay Ghemawat, Jeff Dean, and others.
 //
 // A proto file we will use for unit testing.
+//
+// LINT: ALLOW_GROUPS, LEGACY_NAMES
 
-syntax = "proto2";
-
-// Some generic_services option(s) added automatically.
-// See:  http://go/proto2-generic-services-default
-option cc_generic_services = true;     // auto-added
-option java_generic_services = true;   // auto-added
-option py_generic_services = true;     // auto-added
-
-import "google/protobuf/unittest_import.proto";
+edition = "2023";
 
 // We don't put this in a package within proto2 because we need to make sure
 // that the generated code doesn't depend on being in the proto2 namespace.
-// In test_util.h we do "using namespace unittest = protobuf_unittest".
-package protobuf_unittest;
+// In test_util.h we do "using namespace unittest = proto2_unittest".
+package proto2_unittest;
+
+import "google/protobuf/unittest_import.proto";
+
+option features = {
+  enum_type: CLOSED
+  repeated_field_encoding: EXPANDED
+  utf8_validation: NONE
+};
+
+// Some generic_services option(s) added automatically.
+// See:  http://go/proto2-generic-services-default
+option cc_generic_services = true; // auto-added
+option java_generic_services = true; // auto-added
+option py_generic_services = true; // auto-added
+option cc_enable_arenas = true;
 
 // Protos optimized for SPEED use a strict superset of the generated code
 // of equivalent ones optimized for CODE_SIZE, so we should optimize all our
 // tests for speed unless explicitly testing code size optimization.
 option optimize_for = SPEED;
-
 option java_outer_classname = "UnittestProto";
 
 // This proto includes every type of field in both singular and repeated
@@ -63,120 +48,279 @@
     // The field name "b" fails to compile in proto1 because it conflicts with
     // a local variable named "b" in one of the generated methods.  Doh.
     // This file needs to compile in proto1 to test backwards-compatibility.
-    optional int32 bb = 1;
-    optional int32 i = 2;
+    int32 bb = 1;
   }
 
   enum NestedEnum {
     FOO = 1;
     BAR = 2;
     BAZ = 3;
+    NEG = -1; // Intentionally negative.
   }
 
   // Singular
-  optional    int32 optional_int32    =  1;
-  optional    int64 optional_int64    =  2;
-  optional   uint32 optional_uint32   =  3;
-  optional   uint64 optional_uint64   =  4;
-  optional   sint32 optional_sint32   =  5;
-  optional   sint64 optional_sint64   =  6;
-  optional  fixed32 optional_fixed32  =  7;
-  optional  fixed64 optional_fixed64  =  8;
-  optional sfixed32 optional_sfixed32 =  9;
-  optional sfixed64 optional_sfixed64 = 10;
-  optional    float optional_float    = 11;
-  optional   double optional_double   = 12;
-  optional     bool optional_bool     = 13;
-  optional   string optional_string   = 14;
-  optional    bytes optional_bytes    = 15;
+  int32 optional_int32 = 1;
+  int64 optional_int64 = 2;
+  uint32 optional_uint32 = 3;
+  uint64 optional_uint64 = 4;
+  sint32 optional_sint32 = 5;
+  sint64 optional_sint64 = 6;
+  fixed32 optional_fixed32 = 7;
+  fixed64 optional_fixed64 = 8;
+  sfixed32 optional_sfixed32 = 9;
+  sfixed64 optional_sfixed64 = 10;
+  float optional_float = 11;
+  double optional_double = 12;
+  bool optional_bool = 13;
+  string optional_string = 14;
+  bytes optional_bytes = 15;
 
-  optional group OptionalGroup = 16 {
-    optional int32 a = 17;
+  message OptionalGroup {
+    int32 a = 17;
   }
 
-  optional NestedMessage                        optional_nested_message  = 18;
-  optional ForeignMessage                       optional_foreign_message = 19;
-  optional protobuf_unittest_import.ImportMessage optional_import_message  = 20;
+  OptionalGroup optionalgroup = 16 [
+    features.message_encoding = DELIMITED
+  ];
 
-  optional NestedEnum                           optional_nested_enum     = 21;
-  optional ForeignEnum                          optional_foreign_enum    = 22;
-  optional protobuf_unittest_import.ImportEnum    optional_import_enum     = 23;
+  NestedMessage optional_nested_message = 18;
+  ForeignMessage optional_foreign_message = 19;
+  proto2_unittest_import.ImportMessage optional_import_message = 20;
+  NestedEnum optional_nested_enum = 21;
+  ForeignEnum optional_foreign_enum = 22;
+  proto2_unittest_import.ImportEnum optional_import_enum = 23;
+  string optional_string_piece = 24 [
+    ctype = STRING_PIECE
+  ];
 
-  optional string optional_string_piece = 24 [ctype=STRING_PIECE];
-  optional string optional_cord = 25 [ctype=CORD];
+  string optional_cord = 25 [
+    ctype = CORD
+  ];
+  bytes optional_bytes_cord = 86 [ctype=CORD];
+
+  // Defined in unittest_import_public.proto
+  proto2_unittest_import.PublicImportMessage optional_public_import_message = 26;
+  NestedMessage optional_lazy_message = 27 [
+    lazy = true
+  ];
+
+  NestedMessage optional_unverified_lazy_message = 28 [
+    unverified_lazy = true
+  ];
 
   // Repeated
-  repeated    int32 repeated_int32    = 31;
-  repeated    int64 repeated_int64    = 32;
-  repeated   uint32 repeated_uint32   = 33;
-  repeated   uint64 repeated_uint64   = 34;
-  repeated   sint32 repeated_sint32   = 35;
-  repeated   sint64 repeated_sint64   = 36;
-  repeated  fixed32 repeated_fixed32  = 37;
-  repeated  fixed64 repeated_fixed64  = 38;
+  repeated int32 repeated_int32 = 31;
+  repeated int64 repeated_int64 = 32;
+  repeated uint32 repeated_uint32 = 33;
+  repeated uint64 repeated_uint64 = 34;
+  repeated sint32 repeated_sint32 = 35;
+  repeated sint64 repeated_sint64 = 36;
+  repeated fixed32 repeated_fixed32 = 37;
+  repeated fixed64 repeated_fixed64 = 38;
   repeated sfixed32 repeated_sfixed32 = 39;
   repeated sfixed64 repeated_sfixed64 = 40;
-  repeated    float repeated_float    = 41;
-  repeated   double repeated_double   = 42;
-  repeated     bool repeated_bool     = 43;
-  repeated   string repeated_string   = 44;
-  repeated    bytes repeated_bytes    = 45;
+  repeated float repeated_float = 41;
+  repeated double repeated_double = 42;
+  repeated bool repeated_bool = 43;
+  repeated string repeated_string = 44;
+  repeated bytes repeated_bytes = 45;
 
-  repeated group RepeatedGroup = 46 {
-    optional int32 a = 47;
+  message RepeatedGroup {
+    int32 a = 47;
   }
 
-  repeated NestedMessage                        repeated_nested_message  = 48;
-  repeated ForeignMessage                       repeated_foreign_message = 49;
-  repeated protobuf_unittest_import.ImportMessage repeated_import_message  = 50;
+  repeated RepeatedGroup repeatedgroup = 46 [
+    features.message_encoding = DELIMITED
+  ];
 
-  repeated NestedEnum                           repeated_nested_enum     = 51;
-  repeated ForeignEnum                          repeated_foreign_enum    = 52;
-  repeated protobuf_unittest_import.ImportEnum    repeated_import_enum     = 53;
+  repeated NestedMessage repeated_nested_message = 48;
+  repeated ForeignMessage repeated_foreign_message = 49;
+  repeated proto2_unittest_import.ImportMessage repeated_import_message = 50;
+  repeated NestedEnum repeated_nested_enum = 51;
+  repeated ForeignEnum repeated_foreign_enum = 52;
+  repeated proto2_unittest_import.ImportEnum repeated_import_enum = 53;
+  repeated string repeated_string_piece = 54 [
+    ctype = STRING_PIECE
+  ];
 
-  repeated string repeated_string_piece = 54 [ctype=STRING_PIECE];
-  repeated string repeated_cord = 55 [ctype=CORD];
+  repeated string repeated_cord = 55 [
+    ctype = CORD
+  ];
+
+  repeated NestedMessage repeated_lazy_message = 57 [
+    lazy = true
+  ];
 
   // Singular with defaults
-  optional    int32 default_int32    = 61 [default =  41    ];
-  optional    int64 default_int64    = 62 [default =  42    ];
-  optional   uint32 default_uint32   = 63 [default =  43    ];
-  optional   uint64 default_uint64   = 64 [default =  44    ];
-  optional   sint32 default_sint32   = 65 [default = -45    ];
-  optional   sint64 default_sint64   = 66 [default =  46    ];
-  optional  fixed32 default_fixed32  = 67 [default =  47    ];
-  optional  fixed64 default_fixed64  = 68 [default =  48    ];
-  optional sfixed32 default_sfixed32 = 69 [default =  49    ];
-  optional sfixed64 default_sfixed64 = 70 [default = -50    ];
-  optional    float default_float    = 71 [default =  51.5  ];
-  optional   double default_double   = 72 [default =  52e3  ];
-  optional     bool default_bool     = 73 [default = true   ];
-  optional   string default_string   = 74 [default = "hello"];
-  optional    bytes default_bytes    = 75 [default = "world"];
+  int32 default_int32 = 61 [
+    default = 41
+  ];
 
-  optional NestedEnum  default_nested_enum  = 81 [default = BAR        ];
-  optional ForeignEnum default_foreign_enum = 82 [default = FOREIGN_BAR];
-  optional protobuf_unittest_import.ImportEnum
-      default_import_enum = 83 [default = IMPORT_BAR];
+  int64 default_int64 = 62 [
+    default = 42
+  ];
 
-  optional string default_string_piece = 84 [ctype=STRING_PIECE,default="abc"];
-  optional string default_cord = 85 [ctype=CORD,default="123"];
+  uint32 default_uint32 = 63 [
+    default = 43
+  ];
+
+  uint64 default_uint64 = 64 [
+    default = 44
+  ];
+
+  sint32 default_sint32 = 65 [
+    default = -45
+  ];
+
+  sint64 default_sint64 = 66 [
+    default = 46
+  ];
+
+  fixed32 default_fixed32 = 67 [
+    default = 47
+  ];
+
+  fixed64 default_fixed64 = 68 [
+    default = 48
+  ];
+
+  sfixed32 default_sfixed32 = 69 [
+    default = 49
+  ];
+
+  sfixed64 default_sfixed64 = 70 [
+    default = -50
+  ];
+
+  float default_float = 71 [
+    default = 51.5
+  ];
+
+  double default_double = 72 [
+    default = 5.2e4
+  ];
+
+  bool default_bool = 73 [
+    default = true
+  ];
+
+  string default_string = 74 [
+    default = "hello"
+  ];
+
+  bytes default_bytes = 75 [
+    default = "world"
+  ];
+
+  NestedEnum default_nested_enum = 81 [
+    default = BAR
+  ];
+
+  ForeignEnum default_foreign_enum = 82 [
+    default = FOREIGN_BAR
+  ];
+
+  proto2_unittest_import.ImportEnum default_import_enum = 83 [
+    default = IMPORT_BAR
+  ];
+
+  string default_string_piece = 84 [
+    ctype = STRING_PIECE,
+    default = "abc"
+  ];
+
+  string default_cord = 85 [
+    ctype = CORD,
+    default = "123"
+  ];
+
+  // For oneof test
+  oneof oneof_field {
+    uint32 oneof_uint32 = 111;
+    NestedMessage oneof_nested_message = 112;
+    string oneof_string = 113;
+    bytes oneof_bytes = 114;
+    string oneof_cord = 115 [
+      ctype = CORD
+    ];
+
+    string oneof_string_piece = 116 [
+      ctype = STRING_PIECE
+    ];
+
+    NestedMessage oneof_lazy_nested_message = 117 [
+      lazy = true
+    ];
+  }
+}
+
+// This proto includes a recursively nested message.
+message NestedTestAllTypes {
+  NestedTestAllTypes child = 1;
+  TestAllTypes payload = 2;
+  repeated NestedTestAllTypes repeated_child = 3;
+  NestedTestAllTypes lazy_child = 4 [
+    lazy = true
+  ];
+
+  TestAllTypes eager_child = 5 [
+    lazy = false
+  ];
 }
 
 message TestDeprecatedFields {
-  optional int32 deprecated_int32 = 1 [deprecated=true];
+  int32 deprecated_int32 = 1 [
+    deprecated = true
+  ];
+
+  repeated string deprecated_repeated_string = 4 [
+    deprecated = true
+  ];
+
+  TestAllTypes.NestedMessage deprecated_message = 3 [
+    deprecated = true
+  ];
+
+  oneof oneof_fields {
+    int32 deprecated_int32_in_oneof = 2 [
+      deprecated = true
+    ];
+  }
+
+  TestDeprecatedFields nested = 5;
+}
+
+message TestDeprecatedMessage {
+  option deprecated = true;
 }
 
 // Define these after TestAllTypes to make sure the compiler can handle
 // that.
 message ForeignMessage {
-  optional int32 c = 1;
+  int32 c = 1;
+  int32 d = 2;
 }
 
 enum ForeignEnum {
   FOREIGN_FOO = 4;
   FOREIGN_BAR = 5;
   FOREIGN_BAZ = 6;
+  FOREIGN_BAX = 32; // (1 << 32) to generate a 64b bitmask would be incorrect.
+  FOREIGN_LARGE = 123456; // Large enough to escape the Boxed Integer cache.
+}
+
+message TestReservedFields {
+  reserved 2, 15, 9 to 11;
+
+  reserved bar, baz;
+}
+
+enum TestReservedEnumFields {
+  UNKNOWN = 0;
+
+  reserved 2, 15, 9 to 11;
+
+  reserved bar, baz;
 }
 
 message TestAllExtensions {
@@ -185,108 +329,397 @@
 
 extend TestAllExtensions {
   // Singular
-  optional    int32 optional_int32_extension    =  1;
-  optional    int64 optional_int64_extension    =  2;
-  optional   uint32 optional_uint32_extension   =  3;
-  optional   uint64 optional_uint64_extension   =  4;
-  optional   sint32 optional_sint32_extension   =  5;
-  optional   sint64 optional_sint64_extension   =  6;
-  optional  fixed32 optional_fixed32_extension  =  7;
-  optional  fixed64 optional_fixed64_extension  =  8;
-  optional sfixed32 optional_sfixed32_extension =  9;
-  optional sfixed64 optional_sfixed64_extension = 10;
-  optional    float optional_float_extension    = 11;
-  optional   double optional_double_extension   = 12;
-  optional     bool optional_bool_extension     = 13;
-  optional   string optional_string_extension   = 14;
-  optional    bytes optional_bytes_extension    = 15;
+  int32 optional_int32_extension = 1;
+  int64 optional_int64_extension = 2;
+  uint32 optional_uint32_extension = 3;
+  uint64 optional_uint64_extension = 4;
+  sint32 optional_sint32_extension = 5;
+  sint64 optional_sint64_extension = 6;
+  fixed32 optional_fixed32_extension = 7;
+  fixed64 optional_fixed64_extension = 8;
+  sfixed32 optional_sfixed32_extension = 9;
+  sfixed64 optional_sfixed64_extension = 10;
+  float optional_float_extension = 11;
+  double optional_double_extension = 12;
+  bool optional_bool_extension = 13;
+  string optional_string_extension = 14;
+  bytes optional_bytes_extension = 15;
+  OptionalGroup_extension optionalgroup_extension = 16 [
+    features.message_encoding = DELIMITED
+  ];
 
-  optional group OptionalGroup_extension = 16 {
-    optional int32 a = 17;
-  }
+  TestAllTypes.NestedMessage optional_nested_message_extension = 18;
+  ForeignMessage optional_foreign_message_extension = 19;
+  proto2_unittest_import.ImportMessage optional_import_message_extension = 20;
+  TestAllTypes.NestedEnum optional_nested_enum_extension = 21;
+  ForeignEnum optional_foreign_enum_extension = 22;
+  proto2_unittest_import.ImportEnum optional_import_enum_extension = 23;
+  string optional_string_piece_extension = 24 [
+    ctype = STRING_PIECE
+  ];
 
-  optional TestAllTypes.NestedMessage optional_nested_message_extension = 18;
-  optional ForeignMessage optional_foreign_message_extension = 19;
-  optional protobuf_unittest_import.ImportMessage
-    optional_import_message_extension = 20;
+  // TODO: ctype=CORD is not supported for extension. Add
+  // ctype=CORD option back after it is supported.
+  string optional_cord_extension = 25;
+  bytes optional_bytes_cord_extension = 86;
 
-  optional TestAllTypes.NestedEnum optional_nested_enum_extension = 21;
-  optional ForeignEnum optional_foreign_enum_extension = 22;
-  optional protobuf_unittest_import.ImportEnum
-    optional_import_enum_extension = 23;
+  proto2_unittest_import.PublicImportMessage
+      optional_public_import_message_extension = 26;
+  TestAllTypes.NestedMessage optional_lazy_message_extension = 27 [
+    lazy = true
+  ];
 
-  optional string optional_string_piece_extension = 24 [ctype=STRING_PIECE];
-  optional string optional_cord_extension = 25 [ctype=CORD];
+  TestAllTypes.NestedMessage optional_unverified_lazy_message_extension = 28 [
+    unverified_lazy = true
+  ];
 
   // Repeated
-  repeated    int32 repeated_int32_extension    = 31;
-  repeated    int64 repeated_int64_extension    = 32;
-  repeated   uint32 repeated_uint32_extension   = 33;
-  repeated   uint64 repeated_uint64_extension   = 34;
-  repeated   sint32 repeated_sint32_extension   = 35;
-  repeated   sint64 repeated_sint64_extension   = 36;
-  repeated  fixed32 repeated_fixed32_extension  = 37;
-  repeated  fixed64 repeated_fixed64_extension  = 38;
+  repeated int32 repeated_int32_extension = 31;
+  repeated int64 repeated_int64_extension = 32;
+  repeated uint32 repeated_uint32_extension = 33;
+  repeated uint64 repeated_uint64_extension = 34;
+  repeated sint32 repeated_sint32_extension = 35;
+  repeated sint64 repeated_sint64_extension = 36;
+  repeated fixed32 repeated_fixed32_extension = 37;
+  repeated fixed64 repeated_fixed64_extension = 38;
   repeated sfixed32 repeated_sfixed32_extension = 39;
   repeated sfixed64 repeated_sfixed64_extension = 40;
-  repeated    float repeated_float_extension    = 41;
-  repeated   double repeated_double_extension   = 42;
-  repeated     bool repeated_bool_extension     = 43;
-  repeated   string repeated_string_extension   = 44;
-  repeated    bytes repeated_bytes_extension    = 45;
-
-  repeated group RepeatedGroup_extension = 46 {
-    optional int32 a = 47;
-  }
+  repeated float repeated_float_extension = 41;
+  repeated double repeated_double_extension = 42;
+  repeated bool repeated_bool_extension = 43;
+  repeated string repeated_string_extension = 44;
+  repeated bytes repeated_bytes_extension = 45;
+  repeated RepeatedGroup_extension repeatedgroup_extension = 46 [
+    features.message_encoding = DELIMITED
+  ];
 
   repeated TestAllTypes.NestedMessage repeated_nested_message_extension = 48;
   repeated ForeignMessage repeated_foreign_message_extension = 49;
-  repeated protobuf_unittest_import.ImportMessage
-    repeated_import_message_extension = 50;
-
+  repeated proto2_unittest_import.ImportMessage
+      repeated_import_message_extension = 50;
   repeated TestAllTypes.NestedEnum repeated_nested_enum_extension = 51;
   repeated ForeignEnum repeated_foreign_enum_extension = 52;
-  repeated protobuf_unittest_import.ImportEnum
-    repeated_import_enum_extension = 53;
+  repeated proto2_unittest_import.ImportEnum repeated_import_enum_extension = 53;
+  repeated string repeated_string_piece_extension = 54 [
+    ctype = STRING_PIECE
+  ];
 
-  repeated string repeated_string_piece_extension = 54 [ctype=STRING_PIECE];
-  repeated string repeated_cord_extension = 55 [ctype=CORD];
+  // TODO: ctype=CORD is not supported for extension. Add
+  // ctype=CORD option back after it is supported.
+  repeated string repeated_cord_extension = 55;
+  repeated TestAllTypes.NestedMessage repeated_lazy_message_extension = 57 [
+    lazy = true
+  ];
 
   // Singular with defaults
-  optional    int32 default_int32_extension    = 61 [default =  41    ];
-  optional    int64 default_int64_extension    = 62 [default =  42    ];
-  optional   uint32 default_uint32_extension   = 63 [default =  43    ];
-  optional   uint64 default_uint64_extension   = 64 [default =  44    ];
-  optional   sint32 default_sint32_extension   = 65 [default = -45    ];
-  optional   sint64 default_sint64_extension   = 66 [default =  46    ];
-  optional  fixed32 default_fixed32_extension  = 67 [default =  47    ];
-  optional  fixed64 default_fixed64_extension  = 68 [default =  48    ];
-  optional sfixed32 default_sfixed32_extension = 69 [default =  49    ];
-  optional sfixed64 default_sfixed64_extension = 70 [default = -50    ];
-  optional    float default_float_extension    = 71 [default =  51.5  ];
-  optional   double default_double_extension   = 72 [default =  52e3  ];
-  optional     bool default_bool_extension     = 73 [default = true   ];
-  optional   string default_string_extension   = 74 [default = "hello"];
-  optional    bytes default_bytes_extension    = 75 [default = "world"];
+  int32 default_int32_extension = 61 [
+    default = 41
+  ];
 
-  optional TestAllTypes.NestedEnum
-    default_nested_enum_extension = 81 [default = BAR];
-  optional ForeignEnum
-    default_foreign_enum_extension = 82 [default = FOREIGN_BAR];
-  optional protobuf_unittest_import.ImportEnum
-    default_import_enum_extension = 83 [default = IMPORT_BAR];
+  int64 default_int64_extension = 62 [
+    default = 42
+  ];
 
-  optional string default_string_piece_extension = 84 [ctype=STRING_PIECE,
-                                                       default="abc"];
-  optional string default_cord_extension = 85 [ctype=CORD, default="123"];
+  uint32 default_uint32_extension = 63 [
+    default = 43
+  ];
+
+  uint64 default_uint64_extension = 64 [
+    default = 44
+  ];
+
+  sint32 default_sint32_extension = 65 [
+    default = -45
+  ];
+
+  sint64 default_sint64_extension = 66 [
+    default = 46
+  ];
+
+  fixed32 default_fixed32_extension = 67 [
+    default = 47
+  ];
+
+  fixed64 default_fixed64_extension = 68 [
+    default = 48
+  ];
+
+  sfixed32 default_sfixed32_extension = 69 [
+    default = 49
+  ];
+
+  sfixed64 default_sfixed64_extension = 70 [
+    default = -50
+  ];
+
+  float default_float_extension = 71 [
+    default = 51.5
+  ];
+
+  double default_double_extension = 72 [
+    default = 5.2e4
+  ];
+
+  bool default_bool_extension = 73 [
+    default = true
+  ];
+
+  string default_string_extension = 74 [
+    default = "hello"
+  ];
+
+  bytes default_bytes_extension = 75 [
+    default = "world"
+  ];
+
+  TestAllTypes.NestedEnum default_nested_enum_extension = 81 [
+    default = BAR
+  ];
+
+  ForeignEnum default_foreign_enum_extension = 82 [
+    default = FOREIGN_BAR
+  ];
+
+  proto2_unittest_import.ImportEnum default_import_enum_extension = 83 [
+    default = IMPORT_BAR
+  ];
+
+  string default_string_piece_extension = 84 [
+    ctype = STRING_PIECE,
+    default = "abc"
+  ];
+
+  // TODO: ctype=CORD is not supported for extension. Add
+  // ctype=CORD option back after it is supported.
+  string default_cord_extension = 85 [
+    default = "123"
+  ];
+
+  // For oneof test
+  uint32 oneof_uint32_extension = 111;
+  TestAllTypes.NestedMessage oneof_nested_message_extension = 112;
+  string oneof_string_extension = 113;
+  bytes oneof_bytes_extension = 114;
+
+  string optional_utf8_string_extension = 115 [
+    features.utf8_validation = VERIFY
+  ];
+  repeated string repeated_utf8_string_extension = 116 [
+    features.utf8_validation = VERIFY
+  ];
+
+  // Singular message containing required fields; used to test initialization.
+  TestRequired required_message_extension = 117;
+}
+
+message OptionalGroup_extension {
+  int32 a = 17;
+}
+
+message RepeatedGroup_extension {
+  int32 a = 47;
+}
+
+message TestMixedFieldsAndExtensions {
+  int32 a = 1;
+  repeated fixed32 b = 3;
+
+  extensions 2, 4;
+
+  extend TestMixedFieldsAndExtensions {
+    int32 c = 2;
+    repeated fixed32 d = 4;
+  }
+}
+
+message TestGroup {
+  message OptionalGroup {
+    int32 a = 17;
+    int32 zz = 89;  // fast table size must be at least 16, for this
+                    // field to be parsed by the fast parser, since
+                    // 89 - 17 = 72 is a multiple of 8.
+  }
+
+  OptionalGroup optionalgroup = 16 [
+    features.message_encoding = DELIMITED
+  ];
+
+  ForeignEnum optional_foreign_enum = 22;
+}
+
+message TestGroupExtension {
+  extensions 1 to max;
 }
 
 message TestNestedExtension {
   extend TestAllExtensions {
     // Check for bug where string extensions declared in tested scope did not
     // compile.
-    optional string test = 1002 [default="test"];
+    string test = 1002 [
+      default = "test"
+    ];
+
+    // Used to test if generated extension name is correct when there are
+    // underscores.
+    string nested_string_extension = 1003;
   }
+
+  extend TestGroupExtension {
+    OptionalGroup_extension optionalgroup_extension = 16 [
+      features.message_encoding = DELIMITED
+    ];
+
+    ForeignEnum optional_foreign_enum_extension = 22;
+  }
+
+  message OptionalGroup_extension {
+    int32 a = 17;
+  }
+}
+
+message TestChildExtension {
+  string a = 1;
+  string b = 2;
+  TestAllExtensions optional_extension = 3;
+}
+
+// Emulates wireformat data of TestChildExtension with dynamic extension
+// (DynamicExtension).
+message TestChildExtensionData {
+  message NestedTestAllExtensionsData {
+    message NestedDynamicExtensions {
+      int32 a = 1;
+      int32 b = 2;
+    }
+
+    NestedDynamicExtensions dynamic = 409707008;
+  }
+
+  string a = 1;
+  string b = 2;
+  NestedTestAllExtensionsData optional_extension = 3;
+}
+
+message TestNestedChildExtension {
+  int32 a = 1;
+  TestChildExtension child = 2;
+}
+
+// Emulates wireformat data of TestNestedChildExtension with dynamic extension
+// (DynamicExtension).
+message TestNestedChildExtensionData {
+  int32 a = 1;
+  TestChildExtensionData child = 2;
+}
+
+// Required and closed enum fields are considered unknown fields if the value is
+// not valid. We need to make sure it functions as expected.
+message TestRequiredEnum {
+  ForeignEnum required_enum = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  // A dummy optional field.
+  int32 a = 2;
+}
+
+// Required and open enum accepts invalid enum values.
+enum ForeignOpenEnum {
+  option features.enum_type = OPEN;
+
+  FOREIGN_OPEN_UNKNOWN = 0;
+  FOREIGN_OPEN_FOO = 4;
+  FOREIGN_OPEN_BAR = 5;
+  FOREIGN_OPEN_BAZ = 6;
+  FOREIGN_OPEN_BAX = 32;  // (1 << 32) to generate a 64b bitmask would be
+                          // incorrect.
+}
+
+message TestRequiredOpenEnum {
+  ForeignOpenEnum required_enum = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  // A dummy optional field.
+  int32 a = 2;
+}
+
+// TestRequiredEnum + using enum values that won't fit to 64 bitmask.
+message TestRequiredEnumNoMask {
+  enum NestedEnum {
+    UNSPECIFIED = 0;
+    FOO = 2;
+    BAR = 100;
+    BAZ = -1; // Intentionally negative.
+  }
+
+  NestedEnum required_enum = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  // A dummy optional field.
+  int32 a = 2;
+}
+
+message TestRequiredEnumMulti {
+  enum NestedEnum {
+    UNSPECIFIED = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 100;
+  }
+
+  // Intentionally placed in descending field number to force sorting in closed
+  // enum verification.
+  NestedEnum required_enum_4 = 4 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  int32 a_3 = 3;
+  NestedEnum required_enum_2 = 2 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  ForeignEnum required_enum_1 = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+}
+
+message TestRequiredNoMaskMulti {
+  enum NestedEnum {
+    UNSPECIFIED = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 100;
+  }
+
+  // Intentionally placed in descending field number to force sorting in closed
+  // enum verification. Also, using large field numbers to use tag only
+  // matching for required fields.
+  fixed32 required_fixed32_80 = 80 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  fixed32 required_fixed32_70 = 70 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  NestedEnum required_enum_64 = 64 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  NestedEnum required_enum_4 = 4 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  int32 a_3 = 3;
+  NestedEnum required_enum_2 = 2 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  ForeignEnum required_enum_1 = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
 }
 
 // We have separate messages for testing required fields because it's
@@ -295,59 +728,100 @@
 // required filed because the code output is basically identical to
 // optional fields for all types.
 message TestRequired {
-  required int32 a = 1;
-  optional int32 dummy2 = 2;
-  required int32 b = 3;
+  int32 a = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  int32 dummy2 = 2;
+  int32 b = 3 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
 
   extend TestAllExtensions {
-    optional TestRequired single = 1000;
-    repeated TestRequired multi  = 1001;
+    TestRequired single = 1000;
+    repeated TestRequired multi = 1001;
   }
 
   // Pad the field count to 32 so that we can test that IsInitialized()
   // properly checks multiple elements of has_bits_.
-  optional int32 dummy4  =  4;
-  optional int32 dummy5  =  5;
-  optional int32 dummy6  =  6;
-  optional int32 dummy7  =  7;
-  optional int32 dummy8  =  8;
-  optional int32 dummy9  =  9;
-  optional int32 dummy10 = 10;
-  optional int32 dummy11 = 11;
-  optional int32 dummy12 = 12;
-  optional int32 dummy13 = 13;
-  optional int32 dummy14 = 14;
-  optional int32 dummy15 = 15;
-  optional int32 dummy16 = 16;
-  optional int32 dummy17 = 17;
-  optional int32 dummy18 = 18;
-  optional int32 dummy19 = 19;
-  optional int32 dummy20 = 20;
-  optional int32 dummy21 = 21;
-  optional int32 dummy22 = 22;
-  optional int32 dummy23 = 23;
-  optional int32 dummy24 = 24;
-  optional int32 dummy25 = 25;
-  optional int32 dummy26 = 26;
-  optional int32 dummy27 = 27;
-  optional int32 dummy28 = 28;
-  optional int32 dummy29 = 29;
-  optional int32 dummy30 = 30;
-  optional int32 dummy31 = 31;
-  optional int32 dummy32 = 32;
+  int32 dummy4 = 4;
+  int32 dummy5 = 5;
+  int32 dummy6 = 6;
+  int32 dummy7 = 7;
+  int32 dummy8 = 8;
+  int32 dummy9 = 9;
+  int32 dummy10 = 10;
+  int32 dummy11 = 11;
+  int32 dummy12 = 12;
+  int32 dummy13 = 13;
+  int32 dummy14 = 14;
+  int32 dummy15 = 15;
+  int32 dummy16 = 16;
+  int32 dummy17 = 17;
+  int32 dummy18 = 18;
+  int32 dummy19 = 19;
+  int32 dummy20 = 20;
+  int32 dummy21 = 21;
+  int32 dummy22 = 22;
+  int32 dummy23 = 23;
+  int32 dummy24 = 24;
+  int32 dummy25 = 25;
+  int32 dummy26 = 26;
+  int32 dummy27 = 27;
+  int32 dummy28 = 28;
+  int32 dummy29 = 29;
+  int32 dummy30 = 30;
+  int32 dummy31 = 31;
+  int32 dummy32 = 32;
+  int32 c = 33 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
 
-  required int32 c = 33;
+  // Add an optional child message to make this non-trivial for go/pdlazy.
+  ForeignMessage optional_foreign = 34;
+
+  map<string, TestRequired> map_field = 35;
 }
 
 message TestRequiredForeign {
-  optional TestRequired optional_message = 1;
+  TestRequired optional_message = 1;
   repeated TestRequired repeated_message = 2;
-  optional int32 dummy = 3;
+  int32 dummy = 3;
+
+  // Missing required fields must not affect verification of child messages.
+  NestedTestAllTypes optional_lazy_message = 4 [
+    lazy = true
+  ];
+}
+
+message TestRequiredMessage {
+  TestRequired optional_message = 1;
+  repeated TestRequired repeated_message = 2;
+  TestRequired required_message = 3 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+}
+
+message TestRequiredLazyMessage {
+  TestRequired child = 1 [lazy = true];
+  TestRequiredLazyMessage recurse = 2 [lazy = true];
+}
+
+message TestNestedRequiredForeign {
+  TestNestedRequiredForeign child = 1;
+  TestRequiredForeign payload = 2;
+  int32 dummy = 3;
+
+  // optional message to test required closed enum.
+  TestRequiredEnum required_enum = 5;
+  TestRequiredEnumNoMask required_enum_no_mask = 6;
+  TestRequiredEnumMulti required_enum_multi = 7;
+  TestRequiredNoMaskMulti required_no_mask = 9;
 }
 
 // Test that we can use NestedMessage from outside TestAllTypes.
 message TestForeignNested {
-  optional TestAllTypes.NestedMessage foreign_nested = 1;
+  TestAllTypes.NestedMessage foreign_nested = 1;
 }
 
 // TestEmptyMessage is used to test unknown field support.
@@ -360,6 +834,17 @@
   extensions 1 to max;
 }
 
+// Needed for a Python test.
+message TestPickleNestedMessage {
+  message NestedMessage {
+    int32 bb = 1;
+
+    message NestedNestedMessage {
+      int32 cc = 1;
+    }
+  }
+}
+
 message TestMultipleExtensionRanges {
   extensions 42;
   extensions 4143 to 4243;
@@ -370,35 +855,112 @@
 message TestReallyLargeTagNumber {
   // The largest possible tag number is 2^28 - 1, since the wire format uses
   // three bits to communicate wire type.
-  optional int32 a = 1;
-  optional int32 bb = 268435455;
+  int32 a = 1;
+  int32 bb = 268435455;
 }
 
 message TestRecursiveMessage {
-  optional TestRecursiveMessage a = 1;
-  optional int32 i = 2;
+  TestRecursiveMessage a = 1;
+  int32 i = 2;
 }
 
 // Test that mutual recursion works.
 message TestMutualRecursionA {
-  optional TestMutualRecursionB bb = 1;
+  message SubMessage {
+    TestMutualRecursionB b = 1;
+  }
+
+  TestMutualRecursionB bb = 1;
+
+  message SubGroup {
+    SubMessage sub_message = 3; // Needed because of bug in javatest
+    TestAllTypes not_in_this_scc = 4;
+  }
+
+  SubGroup subgroup = 2 [
+    features.message_encoding = DELIMITED
+  ];
+
+  message SubGroupR {
+    TestAllTypes payload = 6;
+  }
+
+  repeated SubGroupR subgroupr = 5 [
+    features.message_encoding = DELIMITED
+  ];
 }
 
 message TestMutualRecursionB {
-  optional TestMutualRecursionA a = 1;
-  optional int32 optional_int32 = 2;
+  TestMutualRecursionA a = 1;
+  int32 optional_int32 = 2;
+}
+
+message TestIsInitialized {
+  message SubMessage {
+    message SubGroup {
+      int32 i = 2 [
+        features.field_presence = LEGACY_REQUIRED
+      ];
+    }
+
+    SubGroup subgroup = 1 [
+      features.message_encoding = DELIMITED
+    ];
+  }
+
+  SubMessage sub_message = 1;
 }
 
 // Test that groups have disjoint field numbers from their siblings and
-// parents.  This is NOT possible in proto1; only proto2.  When attempting
+// parents.  This is NOT possible in proto1; only google.protobuf.  When attempting
 // to compile with proto1, this will emit an error; so we only include it
-// in protobuf_unittest_proto.
-message TestDupFieldNumber {                        // NO_PROTO1
-  optional int32 a = 1;                             // NO_PROTO1
-  optional group Foo = 2 { optional int32 a = 1; }  // NO_PROTO1
-  optional group Bar = 3 { optional int32 a = 1; }  // NO_PROTO1
-}                                                   // NO_PROTO1
+// in proto2_unittest_proto.
+message TestDupFieldNumber {// NO_PROTO1
+  int32 a = 1; // NO_PROTO1
+  message Foo { // NO_PROTO1
+    int32 a = 1; // NO_PROTO1
+  } // NO_PROTO1
+  Foo foo = 2 [features.message_encoding = DELIMITED]; // NO_PROTO1
+  message Bar { // NO_PROTO1
+    int32 a = 1; // NO_PROTO1
+  } // NO_PROTO1
+  Bar bar = 3 [features.message_encoding = DELIMITED]; // NO_PROTO1
+} // NO_PROTO1
 
+// Additional messages for testing lazy fields.
+message TestEagerMessage {
+  TestAllTypes sub_message = 1 [
+    lazy = false
+  ];
+}
+
+message TestLazyMessage {
+  TestAllTypes sub_message = 1 [
+    lazy = true
+  ];
+}
+
+message TestLazyRequiredEnum {
+  TestRequiredOpenEnum optional_required_open_enum = 1 [lazy = true];
+  TestRequiredEnum optional_required_enum = 2 [lazy = true];
+  TestRequiredEnumNoMask optional_required_enum_no_mask = 3 [lazy = true];
+  TestRequiredEnumMulti optional_required_enum_multi = 4 [lazy = true];
+  TestRequiredNoMaskMulti optional_required_no_mask = 5 [lazy = true];
+}
+
+message TestLazyMessageRepeated {
+  repeated TestLazyMessage repeated_message = 1;
+}
+
+message TestEagerMaybeLazy {
+  message NestedMessage {
+    TestPackedTypes packed = 1;
+  }
+
+  TestAllTypes message_foo = 1;
+  TestAllTypes message_bar = 2;
+  NestedMessage message_baz = 3;
+}
 
 // Needed for a Python test.
 message TestNestedMessageHasBits {
@@ -406,9 +968,9 @@
     repeated int32 nestedmessage_repeated_int32 = 1;
     repeated ForeignMessage nestedmessage_repeated_foreignmessage = 2;
   }
-  optional NestedMessage optional_nested_message = 1;
-}
 
+  NestedMessage optional_nested_message = 1;
+}
 
 // Test an enum that has multiple values with the same number.
 enum TestEnumWithDupValue {
@@ -435,126 +997,510 @@
 // Test message with CamelCase field names.  This violates Protocol Buffer
 // standard style.
 message TestCamelCaseFieldNames {
-  optional int32 PrimitiveField = 1;
-  optional string StringField = 2;
-  optional ForeignEnum EnumField = 3;
-  optional ForeignMessage MessageField = 4;
-  optional string StringPieceField = 5 [ctype=STRING_PIECE];
-  optional string CordField = 6 [ctype=CORD];
+  int32 PrimitiveField = 1;
+  string StringField = 2;
+  ForeignEnum EnumField = 3;
+  ForeignMessage MessageField = 4;
+  string StringPieceField = 5 [
+    ctype = STRING_PIECE
+  ];
+
+  string CordField = 6 [
+    ctype = CORD
+  ];
 
   repeated int32 RepeatedPrimitiveField = 7;
   repeated string RepeatedStringField = 8;
   repeated ForeignEnum RepeatedEnumField = 9;
   repeated ForeignMessage RepeatedMessageField = 10;
-  repeated string RepeatedStringPieceField = 11 [ctype=STRING_PIECE];
-  repeated string RepeatedCordField = 12 [ctype=CORD];
-}
+  repeated string RepeatedStringPieceField = 11 [
+    ctype = STRING_PIECE
+  ];
 
+  repeated string RepeatedCordField = 12 [
+    ctype = CORD
+  ];
+}
 
 // We list fields out of order, to ensure that we're using field number and not
 // field index to determine serialization order.
 message TestFieldOrderings {
-  optional string my_string = 11;
-  extensions 2 to 10;
-  optional int64 my_int = 1;
-  extensions 12 to 100;
-  optional float my_float = 101;
-}
+  string my_string = 11;
 
+  extensions 2 to 10;
+
+  int64 my_int = 1;
+
+  extensions 12 to 100;
+
+  float my_float = 101;
+
+  message NestedMessage {
+    int64 oo = 2;
+
+    // The field name "b" fails to compile in proto1 because it conflicts with
+    // a local variable named "b" in one of the generated methods.  Doh.
+    // This file needs to compile in proto1 to test backwards-compatibility.
+    int32 bb = 1;
+  }
+
+  NestedMessage optional_nested_message = 200;
+}
 
 extend TestFieldOrderings {
-  optional string my_extension_string = 50;
-  optional int32 my_extension_int = 5;
+  string my_extension_string = 50;
+  int32 my_extension_int = 5;
 }
 
+message TestExtensionOrderings1 {
+  extend TestFieldOrderings {
+    TestExtensionOrderings1 test_ext_orderings1 = 13;
+  }
+
+  string my_string = 1;
+}
+
+message TestExtensionOrderings2 {
+  extend TestFieldOrderings {
+    TestExtensionOrderings2 test_ext_orderings2 = 12;
+  }
+
+  message TestExtensionOrderings3 {
+    extend TestFieldOrderings {
+      TestExtensionOrderings3 test_ext_orderings3 = 14;
+    }
+
+    string my_string = 1;
+  }
+
+  string my_string = 1;
+}
 
 message TestExtremeDefaultValues {
-  optional bytes escaped_bytes = 1 [default = "\0\001\a\b\f\n\r\t\v\\\'\"\xfe"];
-  optional uint32 large_uint32 = 2 [default = 0xFFFFFFFF];
-  optional uint64 large_uint64 = 3 [default = 0xFFFFFFFFFFFFFFFF];
-  optional  int32 small_int32  = 4 [default = -0x7FFFFFFF];
-  optional  int64 small_int64  = 5 [default = -0x7FFFFFFFFFFFFFFF];
+  bytes escaped_bytes = 1 [
+    default =
+        "\0\001\a\b\f\n\r\t\v\\\'\"\xfe"
+  ];
+
+  uint32 large_uint32 = 2 [
+    default = 0xFFFFFFFF
+  ];
+
+  uint64 large_uint64 = 3 [
+    default = 0xFFFFFFFFFFFFFFFF
+  ];
+
+  int32 small_int32 = 4 [
+    default = -0x7FFFFFFF
+  ];
+
+  int64 small_int64 = 5 [
+    default = -0x7FFFFFFFFFFFFFFF
+  ];
+
+  int32 really_small_int32 = 21 [
+    default = -0x80000000
+  ];
+
+  int64 really_small_int64 = 22 [
+    default = -0x8000000000000000
+  ];
 
   // The default value here is UTF-8 for "\u1234".  (We could also just type
   // the UTF-8 text directly into this text file rather than escape it, but
   // lots of people use editors that would be confused by this.)
-  optional string utf8_string = 6 [default = "\341\210\264"];
+  string utf8_string = 6 [
+    default = "\341\210\264"
+  ];
 
   // Tests for single-precision floating-point values.
-  optional float zero_float = 7 [default = 0];
-  optional float one_float = 8 [default = 1];
-  optional float small_float = 9 [default = 1.5];
-  optional float negative_one_float = 10 [default = -1];
-  optional float negative_float = 11 [default = -1.5];
+  float zero_float = 7 [
+    default = 0
+  ];
+
+  float one_float = 8 [
+    default = 1
+  ];
+
+  float small_float = 9 [
+    default = 1.5
+  ];
+
+  float negative_one_float = 10 [
+    default = -1
+  ];
+
+  float negative_float = 11 [
+    default = -1.5
+  ];
+
   // Using exponents
-  optional float large_float = 12 [default = 2E8];
-  optional float small_negative_float = 13 [default = -8e-28];
+  float large_float = 12 [
+    default = 2e8
+  ];
+
+  float small_negative_float = 13 [
+    default = -8e-28
+  ];
 
   // Text for nonfinite floating-point values.
-  optional double inf_double = 14 [default = inf];
-  optional double neg_inf_double = 15 [default = -inf];
-  optional double nan_double = 16 [default = nan];
-  optional float inf_float = 17 [default = inf];
-  optional float neg_inf_float = 18 [default = -inf];
-  optional float nan_float = 19 [default = nan];
+  double inf_double = 14 [
+    default = inf
+  ];
+
+  double neg_inf_double = 15 [
+    default = -inf
+  ];
+
+  double nan_double = 16 [
+    default = nan
+  ];
+
+  float inf_float = 17 [
+    default = inf
+  ];
+
+  float neg_inf_float = 18 [
+    default = -inf
+  ];
+
+  float nan_float = 19 [
+    default = nan
+  ];
 
   // Tests for C++ trigraphs.
   // Trigraphs should be escaped in C++ generated files, but they should not be
   // escaped for other languages.
   // Note that in .proto file, "\?" is a valid way to escape ? in string
   // literals.
-  optional string cpp_trigraph = 20 [default = "? \? ?? \?? \??? ??/ ?\?-"];
+  string cpp_trigraph = 20 [
+    default = "? \? ?? \?? \??? ??/ ?\?-"
+  ];
+
+  // String defaults containing the character '\000'
+  string string_with_zero = 23 [
+    default = "hel\000lo"
+  ];
+
+  bytes bytes_with_zero = 24 [
+    default = "wor\000ld"
+  ];
+
+  string string_piece_with_zero = 25 [
+    ctype = STRING_PIECE,
+    default = "ab\000c"
+  ];
+
+  string cord_with_zero = 26 [
+    ctype = CORD,
+    default = "12\0003"
+  ];
+
+  string replacement_string = 27 [
+    default = "${unknown}"
+  ];
 }
 
 message SparseEnumMessage {
-  optional TestSparseEnum sparse_enum = 1;
+  TestSparseEnum sparse_enum = 1;
 }
 
 // Test String and Bytes: string is for valid UTF-8 strings
 message OneString {
-  optional string data = 1;
+  string data = 1;
+}
+
+message MoreString {
+  repeated string data = 1;
 }
 
 message OneBytes {
-  optional bytes data = 1;
+  bytes data = 1;
+}
+
+message MoreBytes {
+  repeated bytes data = 1;
+}
+
+message ManyOptionalString {
+  string str1 = 1;
+  string str2 = 2;
+  string str3 = 3;
+  string str4 = 4;
+  string str5 = 5;
+  string str6 = 6;
+  string str7 = 7;
+  string str8 = 8;
+  string str9 = 9;
+  string str10 = 10;
+  string str11 = 11;
+  string str12 = 12;
+  string str13 = 13;
+  string str14 = 14;
+  string str15 = 15;
+  string str16 = 16;
+  string str17 = 17;
+  string str18 = 18;
+  string str19 = 19;
+  string str20 = 20;
+  string str21 = 21;
+  string str22 = 22;
+  string str23 = 23;
+  string str24 = 24;
+  string str25 = 25;
+  string str26 = 26;
+  string str27 = 27;
+  string str28 = 28;
+  string str29 = 29;
+  string str30 = 30;
+  string str31 = 31;
+  string str32 = 32;
+}
+
+// Test int32, uint32, int64, uint64, and bool are all compatible
+message Int32Message {
+  int32 data = 1;
+}
+
+message Uint32Message {
+  uint32 data = 1;
+}
+
+message Int64Message {
+  int64 data = 1;
+}
+
+message Uint64Message {
+  uint64 data = 1;
+}
+
+message BoolMessage {
+  bool data = 1;
+}
+
+// Test oneofs.
+message TestOneof {
+  oneof foo {
+    int32 foo_int = 1;
+    string foo_string = 2;
+    TestAllTypes foo_message = 3;
+    FooGroup foogroup = 4 [
+      features.message_encoding = DELIMITED
+    ];
+  }
+
+  message FooGroup {
+    int32 a = 5;
+    string b = 6;
+  }
+}
+
+message TestOneofBackwardsCompatible {
+  int32 foo_int = 1;
+  string foo_string = 2;
+  TestAllTypes foo_message = 3;
+
+  message FooGroup {
+    int32 a = 5;
+    string b = 6;
+  }
+
+  FooGroup foogroup = 4 [
+    features.message_encoding = DELIMITED
+  ];
+}
+
+message TestOneof2 {
+  oneof foo {
+    int32 foo_int = 1;
+    string foo_string = 2;
+    string foo_cord = 3 [
+      ctype = CORD
+    ];
+
+    string foo_string_piece = 4 [
+      ctype = STRING_PIECE
+    ];
+
+    bytes foo_bytes = 5;
+    NestedEnum foo_enum = 6;
+    NestedMessage foo_message = 7;
+    FooGroup foogroup = 8 [
+      features.message_encoding = DELIMITED
+    ];
+
+    NestedMessage foo_lazy_message = 11 [
+      lazy = true
+    ];
+
+    bytes foo_bytes_cord = 30 [
+      ctype = CORD
+    ];
+  }
+
+  message FooGroup {
+    int32 a = 9;
+    string b = 10;
+  }
+
+  oneof bar {
+    int32 bar_int = 12 [
+      default = 5
+    ];
+
+    string bar_string = 13 [
+      default = "STRING"
+    ];
+
+    string bar_cord = 14 [
+      ctype = CORD,
+      default = "CORD"
+    ];
+
+    string bar_string_piece = 15 [
+      ctype = STRING_PIECE,
+      default = "SPIECE"
+    ];
+
+    bytes bar_bytes = 16 [
+      default = "BYTES"
+    ];
+
+    NestedEnum bar_enum = 17 [
+      default = BAR
+    ];
+
+    string bar_string_with_empty_default = 20 [
+      default = ""
+    ];
+
+    string bar_cord_with_empty_default = 21 [
+      ctype = CORD,
+      default = ""
+    ];
+
+    string bar_string_piece_with_empty_default = 22 [
+      ctype = STRING_PIECE,
+      default = ""
+    ];
+
+    bytes bar_bytes_with_empty_default = 23 [
+      default = ""
+    ];
+  }
+
+  int32 baz_int = 18;
+  string baz_string = 19 [
+    default = "BAZ"
+  ];
+
+  message NestedMessage {
+    int64 moo_int = 1;
+    repeated int32 corge_int = 2;
+    NestedMessage child = 3;
+  }
+
+  enum NestedEnum {
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+  }
+}
+
+message TestRequiredOneof {
+  oneof foo {
+    int32 foo_int = 1;
+    string foo_string = 2;
+    NestedMessage foo_message = 3;
+    NestedMessage foo_lazy_message = 4 [
+      lazy = true
+    ];
+  }
+
+  message NestedMessage {
+    double required_double = 1 [
+      features.field_presence = LEGACY_REQUIRED
+    ];
+  }
 }
 
 // Test messages for packed fields
 
 message TestPackedTypes {
-  repeated    int32 packed_int32    =  90 [packed = true];
-  repeated    int64 packed_int64    =  91 [packed = true];
-  repeated   uint32 packed_uint32   =  92 [packed = true];
-  repeated   uint64 packed_uint64   =  93 [packed = true];
-  repeated   sint32 packed_sint32   =  94 [packed = true];
-  repeated   sint64 packed_sint64   =  95 [packed = true];
-  repeated  fixed32 packed_fixed32  =  96 [packed = true];
-  repeated  fixed64 packed_fixed64  =  97 [packed = true];
-  repeated sfixed32 packed_sfixed32 =  98 [packed = true];
-  repeated sfixed64 packed_sfixed64 =  99 [packed = true];
-  repeated    float packed_float    = 100 [packed = true];
-  repeated   double packed_double   = 101 [packed = true];
-  repeated     bool packed_bool     = 102 [packed = true];
-  repeated ForeignEnum packed_enum  = 103 [packed = true];
+  repeated int32 packed_int32 = 90 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated int64 packed_int64 = 91 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated uint32 packed_uint32 = 92 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated uint64 packed_uint64 = 93 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sint32 packed_sint32 = 94 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sint64 packed_sint64 = 95 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated fixed32 packed_fixed32 = 96 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated fixed64 packed_fixed64 = 97 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sfixed32 packed_sfixed32 = 98 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sfixed64 packed_sfixed64 = 99 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated float packed_float = 100 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated double packed_double = 101 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated bool packed_bool = 102 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated ForeignEnum packed_enum = 103 [
+    features.repeated_field_encoding = PACKED
+  ];
 }
 
 // A message with the same fields as TestPackedTypes, but without packing. Used
 // to test packed <-> unpacked wire compatibility.
 message TestUnpackedTypes {
-  repeated    int32 unpacked_int32    =  90 [packed = false];
-  repeated    int64 unpacked_int64    =  91 [packed = false];
-  repeated   uint32 unpacked_uint32   =  92 [packed = false];
-  repeated   uint64 unpacked_uint64   =  93 [packed = false];
-  repeated   sint32 unpacked_sint32   =  94 [packed = false];
-  repeated   sint64 unpacked_sint64   =  95 [packed = false];
-  repeated  fixed32 unpacked_fixed32  =  96 [packed = false];
-  repeated  fixed64 unpacked_fixed64  =  97 [packed = false];
-  repeated sfixed32 unpacked_sfixed32 =  98 [packed = false];
-  repeated sfixed64 unpacked_sfixed64 =  99 [packed = false];
-  repeated    float unpacked_float    = 100 [packed = false];
-  repeated   double unpacked_double   = 101 [packed = false];
-  repeated     bool unpacked_bool     = 102 [packed = false];
-  repeated ForeignEnum unpacked_enum  = 103 [packed = false];
+  repeated int32 unpacked_int32 = 90;
+  repeated int64 unpacked_int64 = 91;
+  repeated uint32 unpacked_uint32 = 92;
+  repeated uint64 unpacked_uint64 = 93;
+  repeated sint32 unpacked_sint32 = 94;
+  repeated sint64 unpacked_sint64 = 95;
+  repeated fixed32 unpacked_fixed32 = 96;
+  repeated fixed64 unpacked_fixed64 = 97;
+  repeated sfixed32 unpacked_sfixed32 = 98;
+  repeated sfixed64 unpacked_sfixed64 = 99;
+  repeated float unpacked_float = 100;
+  repeated double unpacked_double = 101;
+  repeated bool unpacked_bool = 102;
+  repeated ForeignEnum unpacked_enum = 103;
 }
 
 message TestPackedExtensions {
@@ -562,20 +1508,82 @@
 }
 
 extend TestPackedExtensions {
-  repeated    int32 packed_int32_extension    =  90 [packed = true];
-  repeated    int64 packed_int64_extension    =  91 [packed = true];
-  repeated   uint32 packed_uint32_extension   =  92 [packed = true];
-  repeated   uint64 packed_uint64_extension   =  93 [packed = true];
-  repeated   sint32 packed_sint32_extension   =  94 [packed = true];
-  repeated   sint64 packed_sint64_extension   =  95 [packed = true];
-  repeated  fixed32 packed_fixed32_extension  =  96 [packed = true];
-  repeated  fixed64 packed_fixed64_extension  =  97 [packed = true];
-  repeated sfixed32 packed_sfixed32_extension =  98 [packed = true];
-  repeated sfixed64 packed_sfixed64_extension =  99 [packed = true];
-  repeated    float packed_float_extension    = 100 [packed = true];
-  repeated   double packed_double_extension   = 101 [packed = true];
-  repeated     bool packed_bool_extension     = 102 [packed = true];
-  repeated ForeignEnum packed_enum_extension  = 103 [packed = true];
+  repeated int32 packed_int32_extension = 90 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated int64 packed_int64_extension = 91 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated uint32 packed_uint32_extension = 92 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated uint64 packed_uint64_extension = 93 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sint32 packed_sint32_extension = 94 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sint64 packed_sint64_extension = 95 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated fixed32 packed_fixed32_extension = 96 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated fixed64 packed_fixed64_extension = 97 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sfixed32 packed_sfixed32_extension = 98 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated sfixed64 packed_sfixed64_extension = 99 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated float packed_float_extension = 100 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated double packed_double_extension = 101 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated bool packed_bool_extension = 102 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated ForeignEnum packed_enum_extension = 103 [
+    features.repeated_field_encoding = PACKED
+  ];
+}
+
+message TestUnpackedExtensions {
+  extensions 1 to max;
+}
+
+extend TestUnpackedExtensions {
+  repeated int32 unpacked_int32_extension = 90;
+  repeated int64 unpacked_int64_extension = 91;
+  repeated uint32 unpacked_uint32_extension = 92;
+  repeated uint64 unpacked_uint64_extension = 93;
+  repeated sint32 unpacked_sint32_extension = 94;
+  repeated sint64 unpacked_sint64_extension = 95;
+  repeated fixed32 unpacked_fixed32_extension = 96;
+  repeated fixed64 unpacked_fixed64_extension = 97;
+  repeated sfixed32 unpacked_sfixed32_extension = 98;
+  repeated sfixed64 unpacked_sfixed64_extension = 99;
+  repeated float unpacked_float_extension = 100;
+  repeated double unpacked_double_extension = 101;
+  repeated bool unpacked_bool_extension = 102;
+  repeated ForeignEnum unpacked_enum_extension = 103;
 }
 
 // Used by ExtensionSetTest/DynamicExtensions.  The test actually builds
@@ -587,19 +1595,27 @@
     DYNAMIC_BAR = 2201;
     DYNAMIC_BAZ = 2202;
   }
+
   message DynamicMessageType {
-    optional int32 dynamic_field = 2100;
+    int32 dynamic_field = 2100;
   }
 
-  optional fixed32 scalar_extension = 2000;
-  optional ForeignEnum enum_extension = 2001;
-  optional DynamicEnumType dynamic_enum_extension = 2002;
-
-  optional ForeignMessage message_extension = 2003;
-  optional DynamicMessageType dynamic_message_extension = 2004;
-
+  fixed32 scalar_extension = 2000;
+  ForeignEnum enum_extension = 2001;
+  DynamicEnumType dynamic_enum_extension = 2002;
+  ForeignMessage message_extension = 2003;
+  DynamicMessageType dynamic_message_extension = 2004;
   repeated string repeated_extension = 2005;
-  repeated sint32 packed_extension = 2006 [packed = true];
+  repeated sint32 packed_extension = 2006 [
+    features.repeated_field_encoding = PACKED
+  ];
+}
+
+message TestRepeatedString {
+  repeated string repeated_string1 = 1;
+  repeated string repeated_string2 = 2;
+  repeated bytes repeated_bytes11 = 11;
+  repeated bytes repeated_bytes12 = 12;
 }
 
 message TestRepeatedScalarDifferentTagSizes {
@@ -607,28 +1623,1088 @@
   // used in order to get a tag of the right size; all of the repeated fields
   // in TestAllTypes didn't trigger the check.
   repeated fixed32 repeated_fixed32 = 12;
+
   // Check for a varint type, just for good measure.
-  repeated int32   repeated_int32   = 13;
+  repeated int32 repeated_int32 = 13;
 
   // These have two-byte tags.
   repeated fixed64 repeated_fixed64 = 2046;
-  repeated int64   repeated_int64   = 2047;
+  repeated int64 repeated_int64 = 2047;
 
   // Three byte tags.
-  repeated float   repeated_float   = 262142;
-  repeated uint64  repeated_uint64  = 262143;
+  repeated float repeated_float = 262142;
+  repeated uint64 repeated_uint64 = 262143;
 }
 
+// Test that if an optional or required message/group field appears multiple
+// times in the input, they need to be merged.
+message TestParsingMerge {
+  // RepeatedFieldsGenerator defines matching field types as TestParsingMerge,
+  // except that all fields are repeated. In the tests, we will serialize the
+  // RepeatedFieldsGenerator to bytes, and parse the bytes to TestParsingMerge.
+  // Repeated fields in RepeatedFieldsGenerator are expected to be merged into
+  // the corresponding required/optional fields in TestParsingMerge.
+  message RepeatedFieldsGenerator {
+    repeated TestAllTypes field1 = 1;
+    repeated TestAllTypes field2 = 2;
+    repeated TestAllTypes field3 = 3;
+
+    message Group1 {
+      TestAllTypes field1 = 11;
+    }
+
+    repeated Group1 group1 = 10 [
+      features.message_encoding = DELIMITED
+    ];
+
+    message Group2 {
+      TestAllTypes field1 = 21;
+    }
+
+    repeated Group2 group2 = 20 [
+      features.message_encoding = DELIMITED
+    ];
+
+    repeated TestAllTypes ext1 = 1000;
+    repeated TestAllTypes ext2 = 1001;
+  }
+
+  TestAllTypes required_all_types = 1 [
+    features.field_presence = LEGACY_REQUIRED
+  ];
+
+  TestAllTypes optional_all_types = 2;
+  repeated TestAllTypes repeated_all_types = 3;
+
+  message OptionalGroup {
+    TestAllTypes optional_group_all_types = 11;
+  }
+
+  OptionalGroup optionalgroup = 10 [
+    features.message_encoding = DELIMITED
+  ];
+
+  message RepeatedGroup {
+    TestAllTypes repeated_group_all_types = 21;
+  }
+
+  repeated RepeatedGroup repeatedgroup = 20 [
+    features.message_encoding = DELIMITED
+  ];
+
+  extensions 1000 to max;
+
+  extend TestParsingMerge {
+    TestAllTypes optional_ext = 1000;
+    repeated TestAllTypes repeated_ext = 1001;
+  }
+}
+
+// Test that the correct exception is thrown by parseFrom in a corner case
+// involving merging, extensions, and required fields.
+message TestMergeException {
+  TestAllExtensions all_extensions = 1;
+}
+
+message TestCommentInjectionMessage {
+  // */ <- This should not close the generated doc comment
+  string a = 1 [
+    default = "*/ <- Neither should this."
+  ];
+}
+
+// Used to check that the c++ code generator re-orders messages to reduce
+// padding.
+message TestMessageSize {
+  bool m1 = 1;
+  int64 m2 = 2;
+  bool m3 = 3;
+  string m4 = 4;
+  int32 m5 = 5;
+  int64 m6 = 6;
+}
+
+message OpenEnumMessage {
+  enum TestEnum {
+    option features.enum_type = OPEN;
+
+    UNKNOWN = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+  }
+
+  TestEnum opt_open = 1;
+
+  ForeignEnum opt_closed = 2;
+  repeated TestEnum repeated_open = 3;
+
+  repeated ForeignEnum repeated_closed = 4;
+}
+
+// Tests eager verification of a lazy message field.
+message TestEagerlyVerifiedLazyMessage {
+  message LazyMessage {
+    bytes bytes_field = 1;
+  }
+  LazyMessage lazy_message = 1 [lazy = true];
+}
 
 // Test that RPC services work.
-message FooRequest  {}
-message FooResponse {}
+message FooRequest {
+}
+
+message FooResponse {
+}
+
+message FooClientMessage {
+}
+
+message FooServerMessage {
+}
 
 service TestService {
   rpc Foo(FooRequest) returns (FooResponse);
+
   rpc Bar(BarRequest) returns (BarResponse);
 }
 
+message BarRequest {
+}
 
-message BarRequest  {}
-message BarResponse {}
+message BarResponse {
+}
+
+message TestJsonName {
+  int32 field_name1 = 1;
+  int32 fieldName2 = 2;
+  int32 FieldName3 = 3;
+  int32 _field_name4 = 4;
+  int32 FIELD_NAME5 = 5;
+  int32 field_name6 = 6 [
+    json_name = "@type"
+  ];
+
+  int32 fieldname7 = 7;
+}
+
+message TestHugeFieldNumbers {
+  int32 optional_int32 = 536870000;
+  int32 fixed_32 = 536870001;
+  repeated int32 repeated_int32 = 536870002;
+  repeated int32 packed_int32 = 536870003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  ForeignEnum optional_enum = 536870004;
+  string optional_string = 536870005;
+  bytes optional_bytes = 536870006;
+  ForeignMessage optional_message = 536870007;
+
+  message OptionalGroup {
+    int32 group_a = 536870009;
+  }
+
+  OptionalGroup optionalgroup = 536870008 [
+    features.message_encoding = DELIMITED
+  ];
+
+  map<string, string> string_string_map = 536870010;
+
+  oneof oneof_field {
+    uint32 oneof_uint32 = 536870011;
+    TestAllTypes oneof_test_all_types = 536870012;
+    string oneof_string = 536870013;
+    bytes oneof_bytes = 536870014;
+  }
+
+  bool optional_bool = 536870015;
+  int64 optional_int64 = 536870016;
+  float optional_float = 536870017;
+  double optional_double = 536870018;
+  string optional_utf8_string = 536870019 [
+    features.utf8_validation = VERIFY
+  ];
+  string optional_cord = 536870020 [
+    ctype=CORD, features.utf8_validation = VERIFY
+  ];
+  string optional_string_piece = 536870021 [
+    ctype=STRING_PIECE, features.utf8_validation = VERIFY
+  ];
+
+  extensions 536860000 to 536869999 [
+    declaration = {
+      number: 536860000
+      full_name: ".proto2_unittest.test_all_types"
+      type: ".proto2_unittest.TestAllTypes"
+    }
+  ];
+}
+
+extend TestHugeFieldNumbers {
+  TestAllTypes test_all_types = 536860000;
+}
+
+message TestExtensionInsideTable {
+  int32 field1 = 1;
+  int32 field2 = 2;
+  int32 field3 = 3;
+  int32 field4 = 4;
+
+  extensions 5;
+
+  int32 field6 = 6;
+  int32 field7 = 7;
+  int32 field8 = 8;
+  int32 field9 = 9;
+  int32 field10 = 10;
+}
+
+extend TestExtensionInsideTable {
+  int32 test_extension_inside_table_extension = 5;
+}
+
+// NOTE: Intentionally nested to mirror go/glep.
+message TestNestedGroupExtensionOuter {
+  message Layer1OptionalGroup {
+    message Layer2RepeatedGroup {
+      extensions 3
+      //  NOTE: extension metadata is not supported due to targets such as
+      //  `//google/protobuf_legacy_opensource/src:shell_scripts_test`,
+      //  eee https://screenshot.googleplex.com/Axz2QD8nxjdpyFF
+      // [metadata = {
+      //  NOTE: can't write type there due to some clever build gen code at
+      //  http://google3/google/protobuf/BUILD;l=1247;rcl=411090862
+      //  type: "proto2_unittest.TestNestedGroupExtensionInnerExtension",
+      //  name: "inner",
+      //  }]
+      ;
+
+      string another_field = 6;
+    }
+
+    repeated Layer2RepeatedGroup layer2repeatedgroup = 2 [
+      features.message_encoding = DELIMITED
+    ];
+
+    message Layer2AnotherOptionalRepeatedGroup {
+      string but_why_tho = 5;
+    }
+
+    repeated Layer2AnotherOptionalRepeatedGroup
+        layer2anotheroptionalrepeatedgroup = 4 [
+          features.message_encoding = DELIMITED
+        ];
+  }
+
+  Layer1OptionalGroup layer1optionalgroup = 1 [
+    features.message_encoding = DELIMITED
+  ];
+}
+
+message TestNestedGroupExtensionInnerExtension {
+  string inner_name = 1;
+}
+
+extend TestNestedGroupExtensionOuter.Layer1OptionalGroup.Layer2RepeatedGroup {
+  TestNestedGroupExtensionInnerExtension inner = 3;
+}
+
+enum VeryLargeEnum {
+  ENUM_LABEL_DEFAULT = 0;
+  ENUM_LABEL_1 = 1;
+  ENUM_LABEL_2 = 2;
+  ENUM_LABEL_3 = 3;
+  ENUM_LABEL_4 = 4;
+  ENUM_LABEL_5 = 5;
+  ENUM_LABEL_6 = 6;
+  ENUM_LABEL_7 = 7;
+  ENUM_LABEL_8 = 8;
+  ENUM_LABEL_9 = 9;
+  ENUM_LABEL_10 = 10;
+  ENUM_LABEL_11 = 11;
+  ENUM_LABEL_12 = 12;
+  ENUM_LABEL_13 = 13;
+  ENUM_LABEL_14 = 14;
+  ENUM_LABEL_15 = 15;
+  ENUM_LABEL_16 = 16;
+  ENUM_LABEL_17 = 17;
+  ENUM_LABEL_18 = 18;
+  ENUM_LABEL_19 = 19;
+  ENUM_LABEL_20 = 20;
+  ENUM_LABEL_21 = 21;
+  ENUM_LABEL_22 = 22;
+  ENUM_LABEL_23 = 23;
+  ENUM_LABEL_24 = 24;
+  ENUM_LABEL_25 = 25;
+  ENUM_LABEL_26 = 26;
+  ENUM_LABEL_27 = 27;
+  ENUM_LABEL_28 = 28;
+  ENUM_LABEL_29 = 29;
+  ENUM_LABEL_30 = 30;
+  ENUM_LABEL_31 = 31;
+  ENUM_LABEL_32 = 32;
+  ENUM_LABEL_33 = 33;
+  ENUM_LABEL_34 = 34;
+  ENUM_LABEL_35 = 35;
+  ENUM_LABEL_36 = 36;
+  ENUM_LABEL_37 = 37;
+  ENUM_LABEL_38 = 38;
+  ENUM_LABEL_39 = 39;
+  ENUM_LABEL_40 = 40;
+  ENUM_LABEL_41 = 41;
+  ENUM_LABEL_42 = 42;
+  ENUM_LABEL_43 = 43;
+  ENUM_LABEL_44 = 44;
+  ENUM_LABEL_45 = 45;
+  ENUM_LABEL_46 = 46;
+  ENUM_LABEL_47 = 47;
+  ENUM_LABEL_48 = 48;
+  ENUM_LABEL_49 = 49;
+  ENUM_LABEL_50 = 50;
+  ENUM_LABEL_51 = 51;
+  ENUM_LABEL_52 = 52;
+  ENUM_LABEL_53 = 53;
+  ENUM_LABEL_54 = 54;
+  ENUM_LABEL_55 = 55;
+  ENUM_LABEL_56 = 56;
+  ENUM_LABEL_57 = 57;
+  ENUM_LABEL_58 = 58;
+  ENUM_LABEL_59 = 59;
+  ENUM_LABEL_60 = 60;
+  ENUM_LABEL_61 = 61;
+  ENUM_LABEL_62 = 62;
+  ENUM_LABEL_63 = 63;
+  ENUM_LABEL_64 = 64;
+  ENUM_LABEL_65 = 65;
+  ENUM_LABEL_66 = 66;
+  ENUM_LABEL_67 = 67;
+  ENUM_LABEL_68 = 68;
+  ENUM_LABEL_69 = 69;
+  ENUM_LABEL_70 = 70;
+  ENUM_LABEL_71 = 71;
+  ENUM_LABEL_72 = 72;
+  ENUM_LABEL_73 = 73;
+  ENUM_LABEL_74 = 74;
+  ENUM_LABEL_75 = 75;
+  ENUM_LABEL_76 = 76;
+  ENUM_LABEL_77 = 77;
+  ENUM_LABEL_78 = 78;
+  ENUM_LABEL_79 = 79;
+  ENUM_LABEL_80 = 80;
+  ENUM_LABEL_81 = 81;
+  ENUM_LABEL_82 = 82;
+  ENUM_LABEL_83 = 83;
+  ENUM_LABEL_84 = 84;
+  ENUM_LABEL_85 = 85;
+  ENUM_LABEL_86 = 86;
+  ENUM_LABEL_87 = 87;
+  ENUM_LABEL_88 = 88;
+  ENUM_LABEL_89 = 89;
+  ENUM_LABEL_90 = 90;
+  ENUM_LABEL_91 = 91;
+  ENUM_LABEL_92 = 92;
+  ENUM_LABEL_93 = 93;
+  ENUM_LABEL_94 = 94;
+  ENUM_LABEL_95 = 95;
+  ENUM_LABEL_96 = 96;
+  ENUM_LABEL_97 = 97;
+  ENUM_LABEL_98 = 98;
+  ENUM_LABEL_99 = 99;
+  ENUM_LABEL_100 = 100;
+}
+
+message TestExtensionRangeSerialize {
+  int32 foo_one = 1;
+
+  extensions 2;
+  extensions 3 to 4;
+
+  int32 foo_two = 6;
+  int32 foo_three = 7;
+
+  extensions 9 to 10;
+
+  int32 foo_four = 13;
+
+  extensions 15 to 15;
+  extensions 17 to 17;
+  extensions 19 to 19;
+
+  extend TestExtensionRangeSerialize {
+    int32 bar_one = 2;
+    int32 bar_two = 4;
+    int32 bar_three = 10;
+    int32 bar_four = 15;
+    int32 bar_five = 19;
+  }
+}
+
+message TestVerifyInt32Simple {
+  int32 optional_int32_1 = 1;
+  int32 optional_int32_2 = 2;
+  int32 optional_int32_63 = 63;
+  int32 optional_int32_64 = 64;
+}
+
+message TestVerifyInt32 {
+  int32 optional_int32_1 = 1;
+  int32 optional_int32_2 = 2;
+  int32 optional_int32_63 = 63;
+  int32 optional_int32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyMostlyInt32 {
+  int64 optional_int64_30 = 30;
+  int32 optional_int32_1 = 1;
+  int32 optional_int32_2 = 2;
+  int32 optional_int32_3 = 3;
+  int32 optional_int32_4 = 4;
+  int32 optional_int32_63 = 63;
+  int32 optional_int32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyMostlyInt32BigFieldNumber {
+  int64 optional_int64_30 = 30;
+  int32 optional_int32_300 = 300;
+  int32 optional_int32_1 = 1;
+  int32 optional_int32_2 = 2;
+  int32 optional_int32_3 = 3;
+  int32 optional_int32_4 = 4;
+  int32 optional_int32_63 = 63;
+  int32 optional_int32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyUint32Simple {
+  uint32 optional_uint32_1 = 1;
+  uint32 optional_uint32_2 = 2;
+  uint32 optional_uint32_63 = 63;
+  uint32 optional_uint32_64 = 64;
+}
+
+message TestVerifyUint32 {
+  uint32 optional_uint32_1 = 1;
+  uint32 optional_uint32_2 = 2;
+  uint32 optional_uint32_63 = 63;
+  uint32 optional_uint32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyOneUint32 {
+  uint32 optional_uint32_1 = 1;
+  int32 optional_int32_2 = 2;
+  int32 optional_int32_63 = 63;
+  int32 optional_int32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyOneInt32BigFieldNumber {
+  int32 optional_int32_65 = 65;
+  int64 optional_int64_1 = 1;
+  int64 optional_int64_2 = 2;
+  int64 optional_int64_63 = 63;
+  int64 optional_int64_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyInt32BigFieldNumber {
+  int32 optional_int32_1000 = 1000;
+  int32 optional_int32_65 = 65;
+  int32 optional_int32_1 = 1;
+  int32 optional_int32_2 = 2;
+  int32 optional_int32_63 = 63;
+  int32 optional_int32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyUint32BigFieldNumber {
+  uint32 optional_uint32_1000 = 1000;
+  uint32 optional_uint32_65 = 65;
+  uint32 optional_uint32_1 = 1;
+  uint32 optional_uint32_2 = 2;
+  uint32 optional_uint32_63 = 63;
+  uint32 optional_uint32_64 = 64;
+  TestAllTypes optional_all_types = 9;
+  repeated TestAllTypes repeated_all_types = 10;
+}
+
+message TestVerifyBigFieldNumberUint32 {
+  message Nested {
+    uint32 optional_uint32_5000 = 5000;
+    uint32 optional_uint32_1000 = 1000;
+    uint32 optional_uint32_66 = 66;
+    uint32 optional_uint32_65 = 65;
+    uint32 optional_uint32_1 = 1;
+    uint32 optional_uint32_2 = 2;
+    uint32 optional_uint32_63 = 63;
+    uint32 optional_uint32_64 = 64;
+    Nested optional_nested = 9;
+    repeated Nested repeated_nested = 10;
+  }
+
+  Nested optional_nested = 1;
+}
+
+// This message contains different kind of enums to exercise the different
+// parsers in table-driven.
+message EnumParseTester {
+  enum SeqSmall0 {
+    SEQ_SMALL_0_DEFAULT = 0;
+    SEQ_SMALL_0_1 = 1;
+    SEQ_SMALL_0_2 = 2;
+  }
+
+  SeqSmall0 optional_seq_small_0_lowfield = 1;
+  SeqSmall0 optional_seq_small_0_midfield = 1001;
+  SeqSmall0 optional_seq_small_0_hifield = 1000001;
+  repeated SeqSmall0 repeated_seq_small_0_lowfield = 2;
+  repeated SeqSmall0 repeated_seq_small_0_midfield = 1002;
+  repeated SeqSmall0 repeated_seq_small_0_hifield = 1000002;
+  repeated SeqSmall0 packed_seq_small_0_lowfield = 3 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated SeqSmall0 packed_seq_small_0_midfield = 1003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated SeqSmall0 packed_seq_small_0_hifield = 1000003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  enum SeqSmall1 {
+    SEQ_SMALL_1_DEFAULT = 1;
+    SEQ_SMALL_1_2 = 2;
+    SEQ_SMALL_1_3 = 3;
+  }
+
+  SeqSmall1 optional_seq_small_1_lowfield = 4;
+  SeqSmall1 optional_seq_small_1_midfield = 1004;
+  SeqSmall1 optional_seq_small_1_hifield = 1000004;
+  repeated SeqSmall1 repeated_seq_small_1_lowfield = 5;
+  repeated SeqSmall1 repeated_seq_small_1_midfield = 1005;
+  repeated SeqSmall1 repeated_seq_small_1_hifield = 1000005;
+  repeated SeqSmall1 packed_seq_small_1_lowfield = 6 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated SeqSmall1 packed_seq_small_1_midfield = 1006 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated SeqSmall1 packed_seq_small_1_hifield = 1000006 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  enum SeqLarge {
+    SEQ_LARGE_DEFAULT = -1;
+    SEQ_LARGE_0 = 0;
+    SEQ_LARGE_1 = 1;
+    SEQ_LARGE_2 = 2;
+    SEQ_LARGE_3 = 3;
+    SEQ_LARGE_4 = 4;
+    SEQ_LARGE_5 = 5;
+    SEQ_LARGE_6 = 6;
+    SEQ_LARGE_7 = 7;
+    SEQ_LARGE_8 = 8;
+    SEQ_LARGE_9 = 9;
+    SEQ_LARGE_10 = 10;
+    SEQ_LARGE_11 = 11;
+    SEQ_LARGE_12 = 12;
+    SEQ_LARGE_13 = 13;
+    SEQ_LARGE_14 = 14;
+    SEQ_LARGE_15 = 15;
+    SEQ_LARGE_16 = 16;
+    SEQ_LARGE_17 = 17;
+    SEQ_LARGE_18 = 18;
+    SEQ_LARGE_19 = 19;
+    SEQ_LARGE_20 = 20;
+    SEQ_LARGE_21 = 21;
+    SEQ_LARGE_22 = 22;
+    SEQ_LARGE_23 = 23;
+    SEQ_LARGE_24 = 24;
+    SEQ_LARGE_25 = 25;
+    SEQ_LARGE_26 = 26;
+    SEQ_LARGE_27 = 27;
+    SEQ_LARGE_28 = 28;
+    SEQ_LARGE_29 = 29;
+    SEQ_LARGE_30 = 30;
+    SEQ_LARGE_31 = 31;
+    SEQ_LARGE_32 = 32;
+    SEQ_LARGE_33 = 33;
+  }
+
+  SeqLarge optional_seq_large_lowfield = 7;
+  SeqLarge optional_seq_large_midfield = 1007;
+  SeqLarge optional_seq_large_hifield = 1000007;
+  repeated SeqLarge repeated_seq_large_lowfield = 8;
+  repeated SeqLarge repeated_seq_large_midfield = 1008;
+  repeated SeqLarge repeated_seq_large_hifield = 1000008;
+  repeated SeqLarge packed_seq_large_lowfield = 9 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated SeqLarge packed_seq_large_midfield = 1009 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated SeqLarge packed_seq_large_hifield = 1000009 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  enum Arbitrary {
+    ARBITRARY_DEFAULT = -123123;
+    ARBITRARY_1 = -123;
+    ARBITRARY_2 = 213;
+    ARBITRARY_3 = 213213;
+    ARBITRARY_MIN = -2147483648;
+    ARBITRARY_MAX = 2147483647;
+  }
+
+  Arbitrary optional_arbitrary_lowfield = 10;
+  Arbitrary optional_arbitrary_midfield = 1010;
+  Arbitrary optional_arbitrary_hifield = 1000010;
+  repeated Arbitrary repeated_arbitrary_lowfield = 11;
+  repeated Arbitrary repeated_arbitrary_midfield = 1011;
+  repeated Arbitrary repeated_arbitrary_hifield = 1000011;
+  repeated Arbitrary packed_arbitrary_lowfield = 12 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated Arbitrary packed_arbitrary_midfield = 1012 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated Arbitrary packed_arbitrary_hifield = 1000012 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  extensions 2000000 to max;
+
+  extend EnumParseTester {
+    Arbitrary optional_arbitrary_ext = 2000000;
+    repeated Arbitrary repeated_arbitrary_ext = 2000001;
+    repeated Arbitrary packed_arbitrary_ext = 2000002 [
+      features.repeated_field_encoding = PACKED
+    ];
+  }
+
+  // An arbitrary field we can append to to break the runs of repeated fields.
+  int32 other_field = 99;
+}
+
+// This message contains different kind of bool fields to exercise the different
+// parsers in table-drived.
+message BoolParseTester {
+  bool optional_bool_lowfield = 1;
+  bool optional_bool_midfield = 1001;
+  bool optional_bool_hifield = 1000001;
+  repeated bool repeated_bool_lowfield = 2;
+  repeated bool repeated_bool_midfield = 1002;
+  repeated bool repeated_bool_hifield = 1000002;
+  repeated bool packed_bool_lowfield = 3 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated bool packed_bool_midfield = 1003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated bool packed_bool_hifield = 1000003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  extensions 2000000 to max;
+
+  extend BoolParseTester {
+    bool optional_bool_ext = 2000000;
+    repeated bool repeated_bool_ext = 2000001;
+    repeated bool packed_bool_ext = 2000002 [
+      features.repeated_field_encoding = PACKED
+    ];
+  }
+
+  // An arbitrary field we can append to to break the runs of repeated fields.
+  int32 other_field = 99;
+}
+
+message Int32ParseTester {
+  int32 optional_int32_lowfield = 1;
+  int32 optional_int32_midfield = 1001;
+  int32 optional_int32_hifield = 1000001;
+  repeated int32 repeated_int32_lowfield = 2;
+  repeated int32 repeated_int32_midfield = 1002;
+  repeated int32 repeated_int32_hifield = 1000002;
+  repeated int32 packed_int32_lowfield = 3 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated int32 packed_int32_midfield = 1003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated int32 packed_int32_hifield = 1000003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  extensions 2000000 to max;
+
+  extend Int32ParseTester {
+    int32 optional_int32_ext = 2000000;
+    repeated int32 repeated_int32_ext = 2000001;
+    repeated int32 packed_int32_ext = 2000002 [
+      features.repeated_field_encoding = PACKED
+    ];
+  }
+
+  // An arbitrary field we can append to to break the runs of repeated fields.
+  int32 other_field = 99;
+}
+
+message Int64ParseTester {
+  int64 optional_int64_lowfield = 1;
+  int64 optional_int64_midfield = 1001;
+  int64 optional_int64_hifield = 1000001;
+  repeated int64 repeated_int64_lowfield = 2;
+  repeated int64 repeated_int64_midfield = 1002;
+  repeated int64 repeated_int64_hifield = 1000002;
+  repeated int64 packed_int64_lowfield = 3 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated int64 packed_int64_midfield = 1003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  repeated int64 packed_int64_hifield = 1000003 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  extensions 2000000 to max;
+
+  extend Int64ParseTester {
+    int64 optional_int64_ext = 2000000;
+    repeated int64 repeated_int64_ext = 2000001;
+    repeated int64 packed_int64_ext = 2000002 [
+      features.repeated_field_encoding = PACKED
+    ];
+  }
+
+  // An arbitrary field we can append to to break the runs of repeated fields.
+  int32 other_field = 99;
+}
+
+message InlinedStringIdxRegressionProto {
+  // We mix data to make sure aux ids and inlined string idx do not match.
+  // aux_idx == inlined_string_idx == 1
+  string str1 = 1;
+
+  // aux_idx == 2
+  InlinedStringIdxRegressionProto sub = 2;
+
+  // aux_idx == 3, inlined_string_idx == 2
+  string str2 = 3;
+
+  // aux_idx == 4, inlined_string_idx == 3
+  bytes str3 = 4;
+}
+
+message StringParseTester {
+  string optional_string_lowfield = 1;
+  string optional_string_midfield = 1001;
+  string optional_string_hifield = 1000001;
+  repeated string repeated_string_lowfield = 2;
+  repeated string repeated_string_midfield = 1002;
+  repeated string repeated_string_hifield = 1000002;
+
+  extensions 2000000 to max;
+
+  extend StringParseTester {
+    string optional_string_ext = 2000000;
+    repeated string repeated_string_ext = 2000001;
+  }
+}
+
+message BadFieldNames {
+  int32 OptionalInt32 = 1;
+  int32 for = 2;
+}
+
+message TestNestedMessageRedaction {
+  string optional_unredacted_nested_string = 1;
+  string optional_redacted_nested_string = 2 [
+    debug_redact = true
+  ];
+}
+
+message RedactedFields {
+  string optional_redacted_string = 1 [
+    debug_redact = true
+  ];
+
+  string optional_unredacted_string = 2;
+  repeated string repeated_redacted_string = 3 [
+    debug_redact = true
+  ];
+
+  repeated string repeated_unredacted_string = 4;
+  TestNestedMessageRedaction optional_redacted_message = 5 [
+    debug_redact = true
+  ];
+
+  TestNestedMessageRedaction optional_unredacted_message = 6;
+  repeated TestNestedMessageRedaction repeated_redacted_message = 7 [
+    debug_redact = true
+  ];
+
+  repeated TestNestedMessageRedaction repeated_unredacted_message = 8;
+  map<string, string> map_redacted_string = 9 [
+    debug_redact = true
+  ];
+
+  map<string, string> map_unredacted_string = 10;
+  string optional_redacted_false_string = 11 [
+    debug_redact = false
+  ];
+
+  extensions 20 to 30;
+}
+
+extend RedactedFields {
+  string redacted_extension = 20 [
+    debug_redact = true
+  ];
+}
+
+message TestString {
+  string optional_string = 1;
+}
+
+message TestCord {
+  bytes optional_bytes_cord = 1 [
+    ctype = CORD
+  ];
+
+  bytes optional_bytes_cord_default = 2 [
+    ctype = CORD,
+    default = "hello"
+  ];
+}
+
+message TestPackedEnumSmallRange {
+  enum NestedEnum {
+    UNSPECIFIED = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+  }
+
+  repeated NestedEnum vals = 1 [
+    features.repeated_field_encoding = PACKED
+  ];
+}
+
+message EnumsForBenchmark {
+  enum Flat {
+    A0 = 0;
+    A1 = 1;
+    A2 = 2;
+    A3 = 3;
+    A4 = 4;
+    A5 = 5;
+    A6 = 6;
+    A7 = 7;
+    A8 = 8;
+    A9 = 9;
+    A10 = 10;
+    A11 = 11;
+    A12 = 12;
+    A13 = 13;
+    A14 = 14;
+    A15 = 15;
+  }
+
+  // Has a few holes, bitmap can be used.
+  enum AlmostFlat {
+    B0 = 0;
+    B1 = 1;
+    B2 = 2;
+    B3 = 3;
+    B5 = 5;
+    B6 = 6;
+    B7 = 7;
+    B8 = 8;
+    B9 = 9;
+    B11 = 11;
+    B12 = 12;
+    B13 = 13;
+    B14 = 14;
+    B15 = 15;
+    B17 = 17;
+    B19 = 19;
+  }
+
+  enum Sparse {
+    C536 = 536;
+    C8387 = 8387;
+    C9673 = 9673;
+    C10285 = 10285;
+    C13318 = 13318;
+    C15963 = 15963;
+    C16439 = 16439;
+    C18197 = 18197;
+    C19430 = 19430;
+    C20361 = 20361;
+    C20706 = 20706;
+    C21050 = 21050;
+    C21906 = 21906;
+    C27265 = 27265;
+    C30109 = 30109;
+    C31670 = 31670;
+  }
+}
+
+message TestMessageWithManyRepeatedPtrFields {
+  repeated string repeated_string_1 = 1;
+  repeated string repeated_string_2 = 2;
+  repeated string repeated_string_3 = 3;
+  repeated string repeated_string_4 = 4;
+  repeated string repeated_string_5 = 5;
+  repeated string repeated_string_6 = 6;
+  repeated string repeated_string_7 = 7;
+  repeated string repeated_string_8 = 8;
+  repeated string repeated_string_9 = 9;
+  repeated string repeated_string_10 = 10;
+  repeated string repeated_string_11 = 11;
+  repeated string repeated_string_12 = 12;
+  repeated string repeated_string_13 = 13;
+  repeated string repeated_string_14 = 14;
+  repeated string repeated_string_15 = 15;
+  repeated string repeated_string_16 = 16;
+  repeated string repeated_string_17 = 17;
+  repeated string repeated_string_18 = 18;
+  repeated string repeated_string_19 = 19;
+  repeated string repeated_string_20 = 20;
+  repeated string repeated_string_21 = 21;
+  repeated string repeated_string_22 = 22;
+  repeated string repeated_string_23 = 23;
+  repeated string repeated_string_24 = 24;
+  repeated string repeated_string_25 = 25;
+  repeated string repeated_string_26 = 26;
+  repeated string repeated_string_27 = 27;
+  repeated string repeated_string_28 = 28;
+  repeated string repeated_string_29 = 29;
+  repeated string repeated_string_30 = 30;
+  repeated string repeated_string_31 = 31;
+  repeated string repeated_string_32 = 32;
+}
+
+message MessageCreatorZeroInit {
+  int32 i = 1;
+  double d = 2;
+  MessageCreatorZeroInit m = 3;
+
+  oneof one {
+    string os = 10;
+    string oc = 11 [
+      ctype = CORD
+    ];
+
+    fixed64 of = 12;
+    MessageCreatorZeroInit ol = 13 [
+      lazy = true
+    ];
+  }
+}
+
+message MessageCreatorMemcpy {
+  string s = 1;
+  repeated int32 i = 2 [
+    features.repeated_field_encoding = PACKED
+  ];
+
+  MessageCreatorMemcpy m = 3 [
+    lazy = true
+  ];
+
+  map<int32, int32> m2 = 4;
+}
+
+message MessageCreatorFunc {
+  // This one is ArenaDtorNeeds::kRequired so we must run the constructor.
+  string c = 3 [
+    ctype = CORD
+  ];
+}
+
+message FastParseTableCompression {
+  int32 important_field_1 = 1;
+  int32 important_field_2 = 2;
+  int32 unimportant_field_3 = 3;
+  int32 unimportant_field_4 = 4;
+  int32 unimportant_field_5 = 5;
+  reserved 6, 7, 8;
+
+  int32 unimportant_field_9 = 9;
+  reserved 10;
+  int32 important_field_11 = 11;
+  int32 unimportant_field_12 = 12;
+  reserved 13;
+  int32 important_field_14 = 14;
+  int32 unimportant_field_15 = 15;
+  reserved 16;
+}
+
+message TestMessageForMove_Small {
+  int32 a = 1;
+  int32 b = 2;
+}
+
+message TestMessageForMove_Large {
+  int32 a1 = 1;
+  int32 a2 = 2;
+  int32 a3 = 3;
+  int32 a4 = 4;
+  int32 a5 = 5;
+  int32 a6 = 6;
+  int32 a7 = 7;
+  int32 a8 = 8;
+  int32 a9 = 9;
+  repeated int32 a11 = 11;
+  repeated int32 a12 = 12;
+  repeated int32 a13 = 13;
+  repeated int32 a14 = 14;
+  repeated int32 a15 = 15;
+  repeated int32 a16 = 16;
+  repeated int32 a17 = 17;
+  repeated int32 a18 = 18;
+  repeated int32 a19 = 19;
+  string s101 = 101;
+  string s102 = 102;
+  string s103 = 103;
+  string s104 = 104;
+  string s105 = 105;
+  string s106 = 106;
+  string s107 = 107;
+  string s108 = 108;
+  string s109 = 109;
+  repeated string s111 = 111;
+  repeated string s112 = 112;
+  repeated string s113 = 113;
+  repeated string s114 = 114;
+  repeated string s115 = 115;
+  repeated string s116 = 116;
+  repeated string s117 = 117;
+  repeated string s118 = 118;
+  repeated string s119 = 119;
+}
diff --git a/protoc_plugin/test/protos/google/protobuf/unittest_import.proto b/protoc_plugin/test/protos/google/protobuf/unittest_import.proto
index 936fd34..41abd76 100644
--- a/protoc_plugin/test/protos/google/protobuf/unittest_import.proto
+++ b/protoc_plugin/test/protos/google/protobuf/unittest_import.proto
@@ -17,7 +17,7 @@
 // that the generated code doesn't depend on being in the proto2 namespace.
 // In test_util.h we do
 // "using namespace unittest_import = proto2_unittest_import".
-package protobuf_unittest_import;
+package proto2_unittest_import;
 
 option optimize_for = SPEED;
 option cc_enable_arenas = true;
diff --git a/protoc_plugin/test/protos/google/protobuf/unittest_import_public.proto b/protoc_plugin/test/protos/google/protobuf/unittest_import_public.proto
index ff42814..34701fe 100644
--- a/protoc_plugin/test/protos/google/protobuf/unittest_import_public.proto
+++ b/protoc_plugin/test/protos/google/protobuf/unittest_import_public.proto
@@ -9,7 +9,7 @@
 
 syntax = "proto2";
 
-package protobuf_unittest_import;
+package proto2_unittest_import;
 
 option java_package = "com.google.protobuf.test";
 
diff --git a/protoc_plugin/test/protos/google/protobuf/unittest_optimize_for.proto b/protoc_plugin/test/protos/google/protobuf/unittest_optimize_for.proto
index 0ac952b..147fa4e 100644
--- a/protoc_plugin/test/protos/google/protobuf/unittest_optimize_for.proto
+++ b/protoc_plugin/test/protos/google/protobuf/unittest_optimize_for.proto
@@ -1,32 +1,9 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
 //
-// 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.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
 
 // Author: kenton@google.com (Kenton Varda)
 //  Based on original Protocol Buffers design by
@@ -36,9 +13,9 @@
 
 syntax = "proto2";
 
-import "google/protobuf/unittest.proto";
+package proto2_unittest;
 
-package protobuf_unittest;
+import "google/protobuf/unittest.proto";
 
 option optimize_for = CODE_SIZE;
 
@@ -52,6 +29,11 @@
     optional int32 test_extension = 1234;
     optional TestRequiredOptimizedForSize test_extension2 = 1235;
   }
+
+  oneof foo {
+    int32 integer_field = 2;
+    string string_field = 3;
+  }
 }
 
 message TestRequiredOptimizedForSize {
diff --git a/protoc_plugin/test/protos/multiple_files_test.proto b/protoc_plugin/test/protos/multiple_files_test.proto
index 81010ca..9fc4e7e 100644
--- a/protoc_plugin/test/protos/multiple_files_test.proto
+++ b/protoc_plugin/test/protos/multiple_files_test.proto
@@ -1,72 +1,57 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
 //
-// 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.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
 
 // Author: kenton@google.com (Kenton Varda)
 //
 // A proto file which tests the java_multiple_files option.
 
-syntax = "proto2";
-
-package protobuf_unittest;
+edition = "2023";
 
 // Some generic_services option(s) added automatically.
 // See:  http://go/proto2-generic-services-default
-option java_generic_services = true;   // auto-added
+package proto2_unittest;
 
+import "google/protobuf/descriptor.proto";
 import "google/protobuf/unittest.proto";
 
+option features.enum_type = CLOSED;
+option java_generic_services = true;  // auto-added
 option java_multiple_files = true;
 option java_outer_classname = "MultipleFilesTestProto";
 
 message MessageWithNoOuter {
   message NestedMessage {
-    optional int32 i = 1;
+    int32 i = 1;
   }
+
   enum NestedEnum {
     BAZ = 3;
   }
-  optional NestedMessage nested = 1;
+
+  NestedMessage nested = 1;
   repeated TestAllTypes foreign = 2;
-  optional NestedEnum nested_enum = 3;
-  optional EnumWithNoOuter foreign_enum = 4;
+  NestedEnum nested_enum = 3;
+  EnumWithNoOuter foreign_enum = 4;
+}
+
+extend google.protobuf.EnumValueOptions {
+  int32 enum_value_option = 7654321;
 }
 
 enum EnumWithNoOuter {
-  FOO = 1;
+  FOO = 1 [(enum_value_option) = 12345];
+
   BAR = 2;
 }
 
 service ServiceWithNoOuter {
-  rpc Foo(MessageWithNoOuter) returns(TestAllTypes);
+  rpc Foo(MessageWithNoOuter) returns (TestAllTypes);
 }
 
 extend TestAllExtensions {
-  optional int32 extension_with_outer = 1234567;
+  int32 extension_with_outer = 1234567;
 }
diff --git a/protoc_plugin/test/src/test_util.dart b/protoc_plugin/test/src/test_util.dart
index a48c2df..c846556 100644
--- a/protoc_plugin/test/src/test_util.dart
+++ b/protoc_plugin/test/src/test_util.dart
@@ -40,7 +40,7 @@
   expect(message.hasExtension(Unittest.optionalStringExtension), isTrue);
   expect(message.hasExtension(Unittest.optionalBytesExtension), isTrue);
 
-  expect(message.hasExtension(Unittest.optionalGroupExtension), isTrue);
+  expect(message.hasExtension(Unittest.optionalgroupExtension), isTrue);
   expect(message.hasExtension(Unittest.optionalNestedMessageExtension), isTrue);
   expect(
     message.hasExtension(Unittest.optionalForeignMessageExtension),
@@ -48,7 +48,7 @@
   );
   expect(message.hasExtension(Unittest.optionalImportMessageExtension), isTrue);
 
-  expect(message.getExtension(Unittest.optionalGroupExtension).hasA(), isTrue);
+  expect(message.getExtension(Unittest.optionalgroupExtension).hasA(), isTrue);
   expect(
     message.getExtension(Unittest.optionalNestedMessageExtension).hasBb(),
     isTrue,
@@ -94,7 +94,7 @@
     '116'.codeUnits,
   );
 
-  expect(message.getExtension(Unittest.optionalGroupExtension).a, 117);
+  expect(message.getExtension(Unittest.optionalgroupExtension).a, 117);
   expect(message.getExtension(Unittest.optionalNestedMessageExtension).bb, 118);
   expect(message.getExtension(Unittest.optionalForeignMessageExtension).c, 119);
   expect(message.getExtension(Unittest.optionalImportMessageExtension).d, 120);
@@ -133,7 +133,7 @@
   expect(message.getExtension(Unittest.repeatedStringExtension).length, 2);
   expect(message.getExtension(Unittest.repeatedBytesExtension).length, 2);
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension).length, 2);
+  expect(message.getExtension(Unittest.repeatedgroupExtension).length, 2);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension).length,
     2,
@@ -187,7 +187,7 @@
     '216'.codeUnits,
   );
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension)[0].a, 217);
+  expect(message.getExtension(Unittest.repeatedgroupExtension)[0].a, 217);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension)[0].bb,
     218,
@@ -251,7 +251,7 @@
     '316'.codeUnits,
   );
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension)[1].a, 317);
+  expect(message.getExtension(Unittest.repeatedgroupExtension)[1].a, 317);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension)[1].bb,
     318,
@@ -358,12 +358,12 @@
   expect(message.hasOptionalString(), isTrue);
   expect(message.hasOptionalBytes(), isTrue);
 
-  expect(message.hasOptionalGroup(), isTrue);
+  expect(message.hasOptionalgroup(), isTrue);
   expect(message.hasOptionalNestedMessage(), isTrue);
   expect(message.hasOptionalForeignMessage(), isTrue);
   expect(message.hasOptionalImportMessage(), isTrue);
 
-  expect(message.optionalGroup.hasA(), isTrue);
+  expect(message.optionalgroup.hasA(), isTrue);
   expect(message.optionalNestedMessage.hasBb(), isTrue);
   expect(message.optionalForeignMessage.hasC(), isTrue);
   expect(message.optionalImportMessage.hasD(), isTrue);
@@ -391,7 +391,7 @@
   expect(message.optionalString, '115');
   expect(message.optionalBytes, '116'.codeUnits);
 
-  expect(message.optionalGroup.a, 117);
+  expect(message.optionalgroup.a, 117);
   expect(message.optionalNestedMessage.bb, 118);
   expect(message.optionalForeignMessage.c, 119);
   expect(message.optionalImportMessage.d, 120);
@@ -421,7 +421,7 @@
   expect(message.repeatedString.length, 2);
   expect(message.repeatedBytes.length, 2);
 
-  expect(message.repeatedGroup.length, 2);
+  expect(message.repeatedgroup.length, 2);
   expect(message.repeatedNestedMessage.length, 2);
   expect(message.repeatedForeignMessage.length, 2);
   expect(message.repeatedImportMessage.length, 2);
@@ -448,7 +448,7 @@
   expect(message.repeatedString[0], '215');
   expect(message.repeatedBytes[0], '216'.codeUnits);
 
-  expect(message.repeatedGroup[0].a, 217);
+  expect(message.repeatedgroup[0].a, 217);
   expect(message.repeatedNestedMessage[0].bb, 218);
   expect(message.repeatedForeignMessage[0].c, 219);
   expect(message.repeatedImportMessage[0].d, 220);
@@ -476,7 +476,7 @@
   expect(message.repeatedString[1], '315');
   expect(message.repeatedBytes[1], '316'.codeUnits);
 
-  expect(message.repeatedGroup[1].a, 317);
+  expect(message.repeatedgroup[1].a, 317);
   expect(message.repeatedNestedMessage[1].bb, 318);
   expect(message.repeatedForeignMessage[1].c, 319);
   expect(message.repeatedImportMessage[1].d, 320);
@@ -555,7 +555,7 @@
   expect(message.hasOptionalString(), isFalse);
   expect(message.hasOptionalBytes(), isFalse);
 
-  expect(message.hasOptionalGroup(), isFalse);
+  expect(message.hasOptionalgroup(), isFalse);
   expect(message.hasOptionalNestedMessage(), isFalse);
   expect(message.hasOptionalForeignMessage(), isFalse);
   expect(message.hasOptionalImportMessage(), isFalse);
@@ -585,12 +585,12 @@
   expect(message.optionalBytes, <int>[]);
 
   // Embedded messages should also be clear.
-  expect(message.optionalGroup.hasA(), isFalse);
+  expect(message.optionalgroup.hasA(), isFalse);
   expect(message.optionalNestedMessage.hasBb(), isFalse);
   expect(message.optionalForeignMessage.hasC(), isFalse);
   expect(message.optionalImportMessage.hasD(), isFalse);
 
-  expect(message.optionalGroup.a, 0);
+  expect(message.optionalgroup.a, 0);
   expect(message.optionalNestedMessage.bb, 0);
   expect(message.optionalForeignMessage.c, 0);
   expect(message.optionalImportMessage.d, 0);
@@ -620,7 +620,7 @@
   expect(message.repeatedString.length, 0);
   expect(message.repeatedBytes.length, 0);
 
-  expect(message.repeatedGroup.length, 0);
+  expect(message.repeatedgroup.length, 0);
   expect(message.repeatedNestedMessage.length, 0);
   expect(message.repeatedForeignMessage.length, 0);
   expect(message.repeatedImportMessage.length, 0);
@@ -698,7 +698,7 @@
   expect(message.hasExtension(Unittest.optionalStringExtension), isFalse);
   expect(message.hasExtension(Unittest.optionalBytesExtension), isFalse);
 
-  expect(message.hasExtension(Unittest.optionalGroupExtension), isFalse);
+  expect(message.hasExtension(Unittest.optionalgroupExtension), isFalse);
   expect(
     message.hasExtension(Unittest.optionalNestedMessageExtension),
     isFalse,
@@ -737,7 +737,7 @@
   expect(message.getExtension(Unittest.optionalBytesExtension), <int>[]);
 
   // Embedded messages should also be clear.
-  expect(message.getExtension(Unittest.optionalGroupExtension).hasA(), isFalse);
+  expect(message.getExtension(Unittest.optionalgroupExtension).hasA(), isFalse);
   expect(
     message.getExtension(Unittest.optionalNestedMessageExtension).hasBb(),
     isFalse,
@@ -751,7 +751,7 @@
     isFalse,
   );
 
-  expect(message.getExtension(Unittest.optionalGroupExtension).a, 0);
+  expect(message.getExtension(Unittest.optionalgroupExtension).a, 0);
   expect(message.getExtension(Unittest.optionalNestedMessageExtension).bb, 0);
   expect(message.getExtension(Unittest.optionalForeignMessageExtension).c, 0);
   expect(message.getExtension(Unittest.optionalImportMessageExtension).d, 0);
@@ -790,7 +790,7 @@
   expect(message.getExtension(Unittest.repeatedStringExtension).length, 0);
   expect(message.getExtension(Unittest.repeatedBytesExtension).length, 0);
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension).length, 0);
+  expect(message.getExtension(Unittest.repeatedgroupExtension).length, 0);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension).length,
     0,
@@ -827,7 +827,7 @@
   expect(message.getExtension(Unittest.repeatedStringExtension).length, 0);
   expect(message.getExtension(Unittest.repeatedBytesExtension).length, 0);
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension).length, 0);
+  expect(message.getExtension(Unittest.repeatedgroupExtension).length, 0);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension).length,
     0,
@@ -1050,7 +1050,7 @@
   expect(message.hasExtension(Unittest.optionalStringExtension), isTrue);
   expect(message.hasExtension(Unittest.optionalBytesExtension), isTrue);
 
-  expect(message.hasExtension(Unittest.optionalGroupExtension), isTrue);
+  expect(message.hasExtension(Unittest.optionalgroupExtension), isTrue);
   expect(message.hasExtension(Unittest.optionalNestedMessageExtension), isTrue);
   expect(
     message.hasExtension(Unittest.optionalForeignMessageExtension),
@@ -1058,7 +1058,7 @@
   );
   expect(message.hasExtension(Unittest.optionalImportMessageExtension), isTrue);
 
-  expect(message.getExtension(Unittest.optionalGroupExtension).hasA(), isTrue);
+  expect(message.getExtension(Unittest.optionalgroupExtension).hasA(), isTrue);
   expect(
     message.getExtension(Unittest.optionalNestedMessageExtension).hasBb(),
     isTrue,
@@ -1104,7 +1104,7 @@
     '116'.codeUnits,
   );
 
-  expect(message.getExtension(Unittest.optionalGroupExtension).a, 117);
+  expect(message.getExtension(Unittest.optionalgroupExtension).a, 117);
   expect(message.getExtension(Unittest.optionalNestedMessageExtension).bb, 118);
   expect(message.getExtension(Unittest.optionalForeignMessageExtension).c, 119);
   expect(message.getExtension(Unittest.optionalImportMessageExtension).d, 120);
@@ -1143,7 +1143,7 @@
   expect(message.getExtension(Unittest.repeatedStringExtension).length, 2);
   expect(message.getExtension(Unittest.repeatedBytesExtension).length, 2);
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension).length, 2);
+  expect(message.getExtension(Unittest.repeatedgroupExtension).length, 2);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension).length,
     2,
@@ -1197,7 +1197,7 @@
     '216'.codeUnits,
   );
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension)[0].a, 217);
+  expect(message.getExtension(Unittest.repeatedgroupExtension)[0].a, 217);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension)[0].bb,
     218,
@@ -1261,7 +1261,7 @@
     '516'.codeUnits,
   );
 
-  expect(message.getExtension(Unittest.repeatedGroupExtension)[1].a, 517);
+  expect(message.getExtension(Unittest.repeatedgroupExtension)[1].a, 517);
   expect(
     message.getExtension(Unittest.repeatedNestedMessageExtension)[1].bb,
     518,
@@ -1372,7 +1372,7 @@
   expect(message.repeatedString.length, 2);
   expect(message.repeatedBytes.length, 2);
 
-  expect(message.repeatedGroup.length, 2);
+  expect(message.repeatedgroup.length, 2);
   expect(message.repeatedNestedMessage.length, 2);
   expect(message.repeatedForeignMessage.length, 2);
   expect(message.repeatedImportMessage.length, 2);
@@ -1399,7 +1399,7 @@
   expect(message.repeatedString[0], '215');
   expect(message.repeatedBytes[0], '216'.codeUnits);
 
-  expect(message.repeatedGroup[0].a, 217);
+  expect(message.repeatedgroup[0].a, 217);
   expect(message.repeatedNestedMessage[0].bb, 218);
   expect(message.repeatedForeignMessage[0].c, 219);
   expect(message.repeatedImportMessage[0].d, 220);
@@ -1428,7 +1428,7 @@
   expect(message.repeatedString[1], '515');
   expect(message.repeatedBytes[1], '516'.codeUnits);
 
-  expect(message.repeatedGroup[1].a, 517);
+  expect(message.repeatedgroup[1].a, 517);
   expect(message.repeatedNestedMessage[1].bb, 518);
   expect(message.repeatedForeignMessage[1].c, 519);
   expect(message.repeatedImportMessage[1].d, 520);
@@ -1547,7 +1547,7 @@
 
   msg = RepeatedGroup_extension();
   msg.a = 517;
-  message.getExtension(Unittest.repeatedGroupExtension)[1] = msg;
+  message.getExtension(Unittest.repeatedgroupExtension)[1] = msg;
 
   msg = TestAllTypes_NestedMessage();
   msg.bb = 518;
@@ -1593,7 +1593,7 @@
 
   final repeatedGroup = TestAllTypes_RepeatedGroup();
   repeatedGroup.a = 517;
-  message.repeatedGroup[1] = repeatedGroup;
+  message.repeatedgroup[1] = repeatedGroup;
 
   final optionalNestedMessage = TestAllTypes_NestedMessage();
   optionalNestedMessage.bb = 518;
@@ -1638,7 +1638,7 @@
 
   final msg = OptionalGroup_extension();
   msg.a = 117;
-  message.setExtension(Unittest.optionalGroupExtension, msg);
+  message.setExtension(Unittest.optionalgroupExtension, msg);
 
   final msg2 = TestAllTypes_NestedMessage();
   msg2.bb = 118;
@@ -1688,7 +1688,7 @@
 
   final msg5 = RepeatedGroup_extension();
   msg5.a = 217;
-  message.addExtension(Unittest.repeatedGroupExtension, msg5);
+  message.addExtension(Unittest.repeatedgroupExtension, msg5);
 
   final msg6 = TestAllTypes_NestedMessage();
   msg6.bb = 218;
@@ -1737,7 +1737,7 @@
 
   final msg9 = RepeatedGroup_extension();
   msg9.a = 317;
-  message.addExtension(Unittest.repeatedGroupExtension, msg9);
+  message.addExtension(Unittest.repeatedgroupExtension, msg9);
 
   final msg10 = TestAllTypes_NestedMessage();
   msg10.bb = 318;
@@ -1821,9 +1821,9 @@
   message.optionalString = '115';
   message.optionalBytes = '116'.codeUnits;
 
-  final optionalGroup = TestAllTypes_OptionalGroup();
-  optionalGroup.a = 117;
-  message.optionalGroup = optionalGroup;
+  final optionalgroup = TestAllTypes_OptionalGroup();
+  optionalgroup.a = 117;
+  message.optionalgroup = optionalgroup;
 
   final optionalNestedMessage = TestAllTypes_NestedMessage();
   optionalNestedMessage.bb = 118;
@@ -1864,7 +1864,7 @@
 
   var repeatedGroup = TestAllTypes_RepeatedGroup();
   repeatedGroup.a = 217;
-  message.repeatedGroup.add(repeatedGroup);
+  message.repeatedgroup.add(repeatedGroup);
 
   var repeatedNested = TestAllTypes_NestedMessage();
   repeatedNested.bb = 218;
@@ -1904,7 +1904,7 @@
 
   repeatedGroup = TestAllTypes_RepeatedGroup();
   repeatedGroup.a = 317;
-  message.repeatedGroup.add(repeatedGroup);
+  message.repeatedgroup.add(repeatedGroup);
 
   repeatedNested = TestAllTypes_NestedMessage();
   repeatedNested.bb = 318;
diff --git a/protoc_plugin/test/unknown_field_set_test.dart b/protoc_plugin/test/unknown_field_set_test.dart
index 75b1bac..20cc5de 100644
--- a/protoc_plugin/test/unknown_field_set_test.dart
+++ b/protoc_plugin/test/unknown_field_set_test.dart
@@ -82,7 +82,7 @@
     expect(group.hasField(tagNumberA), isTrue);
     expect(
       group.getField(tagNumberA)!.varints[0],
-      expect64(testAllTypes.optionalGroup.a),
+      expect64(testAllTypes.optionalgroup.a),
     );
   });