From 5e5265b669d5ae5770ba226b4165d473c08c7142 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=96mer=20Sinan=20A=C4=9Facan?= <omeragacan@gmail.com>
Date: Tue, 4 Jul 2023 15:40:36 +0200
Subject: [PATCH] More tests

---
 protoc_plugin/test/message_set_test.dart | 115 +++++++++++++++++------
 1 file changed, 87 insertions(+), 28 deletions(-)

diff --git a/protoc_plugin/test/message_set_test.dart b/protoc_plugin/test/message_set_test.dart
index 8fd64e32..d83ec3c8 100644
--- a/protoc_plugin/test/message_set_test.dart
+++ b/protoc_plugin/test/message_set_test.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:typed_data';
+
 import 'package:fixnum/fixnum.dart';
 import 'package:protobuf/protobuf.dart';
 import 'package:test/test.dart';
@@ -144,55 +146,58 @@ void main() {
     // Generate a message set encoding using unknown fields. Message set item
     // will have extra tags.
 
-    final itemFieldGroup = UnknownFieldSet();
+    final encoded = encodeMessageSetWithExtraItemTags(Encoding.group);
+
+    final registry = ExtensionRegistry()..add(TestMessage.ext1);
+    final decodedMsg = MessageSet.fromBuffer(encoded, registry);
+    final extensionValue =
+        decodedMsg.getExtension(TestMessage.ext1) as ExtensionMessage1;
+
+    expect(extensionValue.a, 123456);
+    expect(extensionValue.b, 'test');
+    expect(decodedMsg.unknownFields.isEmpty, true);
+  });
+
+  test('Ignore extra tags in items (length delimited encoding)', () {
+    // Same as above, but tests length delimited encoding.
 
-    // Invalid field with tag 1.
-    itemFieldGroup.addField(
-        1, UnknownFieldSetField()..addLengthDelimited([1, 2, 3]));
+    final encoded = encodeMessageSetWithExtraItemTags(Encoding.lengthDelimited);
 
-    // Extension field.
-    itemFieldGroup.addField(
-        3,
-        UnknownFieldSetField()
-          ..addLengthDelimited((ExtensionMessage1()
-                ..a = 123456
-                ..b = 'test')
-              .writeToBuffer()));
+    final registry = ExtensionRegistry()..add(TestMessage.ext1);
+    final decodedMsg = MessageSet.fromBuffer(encoded, registry);
+    final extensionValue =
+        decodedMsg.getExtension(TestMessage.ext1) as ExtensionMessage1;
 
-    // Invalid field with tag 3.
-    itemFieldGroup.addField(
-        4, UnknownFieldSetField()..addVarint(Int64(123456)));
+    expect(extensionValue.a, 123456);
+    expect(extensionValue.b, 'test');
+    expect(decodedMsg.unknownFields.isEmpty, true);
+  });
 
-    // Type id field.
-    itemFieldGroup.addField(
-        2, UnknownFieldSetField()..addVarint(Int64(1758024)));
+  test('Ignore invalid tags in repeated items', () {
+    // Extra fields other than `repeated Item items = 1` in the outer message.
 
     final messageSetUnknownFields = UnknownFieldSet();
     messageSetUnknownFields.addField(
-        1, UnknownFieldSetField()..addGroup(itemFieldGroup));
+        2, UnknownFieldSetField()..addVarint(Int64(987)));
 
     final messageSetEncoded = CodedBufferWriter();
     messageSetUnknownFields.writeToCodedBufferWriter(messageSetEncoded);
 
     final encoded = (Empty()
           ..unknownFields.addField(
-              1,
+              123,
               UnknownFieldSetField()
                 ..lengthDelimited.add(messageSetEncoded.toBuffer())))
         .writeToBuffer();
 
     final registry = ExtensionRegistry()..add(TestMessage.ext1);
     final msg = TestMessage.fromBuffer(encoded, registry);
-    final extensionValue =
-        msg.info.getExtension(TestMessage.ext1) as ExtensionMessage1;
-
-    expect(extensionValue.a, 123456);
-    expect(extensionValue.b, 'test');
-    expect(msg.unknownFields.isEmpty, true);
+    expect(msg.info.hasExtension(TestMessage.ext1), false);
   });
 
-  test('Ignore invalid tags in repeated items', () {
-    // Extra fields other than `repeated Item items = 1` in the outer message.
+  test('Encode message set as length prefixed', () {
+    // Message sets are generally encoded as groups, but we support length
+    // delimited as well.
 
     final messageSetUnknownFields = UnknownFieldSet();
     messageSetUnknownFields.addField(
@@ -213,3 +218,57 @@ void main() {
     expect(msg.info.hasExtension(TestMessage.ext1), false);
   });
 }
+
+enum Encoding {
+  lengthDelimited,
+  group,
+}
+
+/// Generate a message set encoding with one extension. Extension will have
+/// extra tags.
+Uint8List encodeMessageSetWithExtraItemTags(Encoding encoding) {
+  final itemFieldGroup = UnknownFieldSet();
+
+  // Invalid field with tag 1.
+  itemFieldGroup.addField(
+      1, UnknownFieldSetField()..addLengthDelimited([1, 2, 3]));
+
+  // Extension field.
+  itemFieldGroup.addField(
+      3,
+      UnknownFieldSetField()
+        ..addLengthDelimited((ExtensionMessage1()
+              ..a = 123456
+              ..b = 'test')
+            .writeToBuffer()));
+
+  // Invalid field with tag 3.
+  itemFieldGroup.addField(4, UnknownFieldSetField()..addVarint(Int64(123456)));
+
+  // Type id field.
+  itemFieldGroup.addField(2, UnknownFieldSetField()..addVarint(Int64(1758024)));
+
+  final messageSet = Empty();
+  final messageSetUnknownFields = messageSet.unknownFields;
+
+  switch (encoding) {
+    case Encoding.lengthDelimited:
+      final writer = CodedBufferWriter();
+      itemFieldGroup.writeToCodedBufferWriter(writer);
+      messageSetUnknownFields.addField(
+          1, UnknownFieldSetField()..addLengthDelimited(writer.toBuffer()));
+      break;
+    case Encoding.group:
+      messageSetUnknownFields.addField(
+          1, UnknownFieldSetField()..addGroup(itemFieldGroup));
+      break;
+  }
+
+  messageSetUnknownFields.addField(
+      1, UnknownFieldSetField()..addGroup(itemFieldGroup));
+
+  final messageSetEncoded = CodedBufferWriter();
+  messageSetUnknownFields.writeToCodedBufferWriter(messageSetEncoded);
+
+  return messageSet.writeToBuffer();
+}