model: Add Submessage.

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/api/model/model.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:json_annotation/json_annotation.dart';
 
 import 'events.dart';
@@ -481,7 +483,7 @@ sealed class Message {
   final String senderRealmStr;
   @JsonKey(name: 'subject')
   final String topic;
-  // final List<string> submessages; // TODO handle
+  final List<Submessage> submessages;
   final int timestamp;
   String get type;
 
@@ -528,6 +530,7 @@ sealed class Message {
     required this.senderId,
     required this.senderRealmStr,
     required this.topic,
+    required this.submessages,
     required this.timestamp,
     required this.flags,
     required this.matchContent,
@@ -570,6 +573,41 @@ enum MessageFlag {
   String toJson() => _$MessageFlagEnumMap[this]!;
 }
 
+/// https://zulip.com/api/get-messages#response
+@JsonSerializable(fieldRename: FieldRename.snake)
+class Submessage {
+  const Submessage({
+    required this.msgType,
+    required this.content,
+    required this.messageId,
+    required this.senderId,
+    required this.id,
+  });
+
+  @JsonKey(unknownEnumValue: SubmessageType.unknown)
+  final SubmessageType msgType;
+  /// JSON-encoded string representing any of the possible [WidgetData].
+  @JsonKey(readValue: _readContent)
+  final Object? content;
+  final int messageId;
+  final int senderId;
+  final int id;
+
+  static Object? _readContent(Map<Object?, Object?> json, String key) {
+    return (const JsonDecoder().convert(json[key] as String)) as Object?;
+  }
+
+  factory Submessage.fromJson(Map<String, dynamic> json) =>
+    _$SubmessageFromJson(json);
+
+  Map<String, dynamic> toJson() => _$SubmessageToJson(this);
+}
+
+enum SubmessageType {
+  widget,
+  unknown,
+}
+
 @JsonSerializable(fieldRename: FieldRename.snake)
 class StreamMessage extends Message {
   @override
@@ -595,6 +633,7 @@ class StreamMessage extends Message {
     required super.senderRealmStr,
     required super.topic,
     required super.timestamp,
+    required super.submessages,
     required super.flags,
     required super.matchContent,
     required super.matchTopic,
@@ -697,6 +736,7 @@ class DmMessage extends Message {
     required super.senderId,
     required super.senderRealmStr,
     required super.topic,
+    required super.submessages,
     required super.timestamp,
     required super.flags,
     required super.matchContent,

lib/api/model/model.g.dart

@@ -42,13 +42,22 @@ extension MessageChecks on Subject<Message> {
   Subject<int> get senderId => has((e) => e.senderId, 'senderId');
   Subject<String> get senderRealmStr => has((e) => e.senderRealmStr, 'senderRealmStr');
   Subject<String> get topic => has((e) => e.topic, 'topic');
+  Subject<List<Submessage>> get submessages => has((e) => e.submessages, 'submessages');
   Subject<int> get timestamp => has((e) => e.timestamp, 'timestamp');
   Subject<String> get type => has((e) => e.type, 'type');
   Subject<List<MessageFlag>> get flags => has((e) => e.flags, 'flags');
   Subject<String?> get matchContent => has((e) => e.matchContent, 'matchContent');
   Subject<String?> get matchTopic => has((e) => e.matchTopic, 'matchTopic');
 }
 
+extension SubMessageChecks on Subject<Submessage> {
+  Subject<SubmessageType> get msgType => has((e) => e.msgType, 'msgType');
+  Subject<Object?> get content => has((e) => e.content, 'content');
+  Subject<int> get messageId => has((e) => e.messageId, 'messageId');
+  Subject<int> get senderId => has((e) => e.senderId, 'senderId');
+  Subject<int> get id => has((e) => e.id, 'id');
+}
+
 extension ReactionsChecks on Subject<Reactions> {
   Subject<int> get total => has((e) => e.total, 'total');
   Subject<List<ReactionWithVotes>> get aggregated => has((e) => e.aggregated, 'aggregated');

test/api/model/model_checks.dart

@@ -149,6 +149,51 @@ void main() {
       check(m2).flags.deepEquals([MessageFlag.read, MessageFlag.unknown]);
     });
 
+    test('no crash on unrecognized submessage type', () {
+      final streamMessage = eg.streamMessage(sender: eg.selfUser);
+      final dmMessage = eg.dmMessage(from: eg.selfUser, to: [eg.otherUser]);
+      final submessage = {
+        'msg_type': 'unknown_widget',
+        'content': '',
+        'sender_id': eg.selfUser.userId,
+        'id': 1,
+      };
+
+      check(Message.fromJson(
+        (deepToJson(streamMessage) as Map<String, dynamic>)
+          ..['submessages'] = [submessage..['message_id'] = streamMessage.id],
+      )).submessages.single.msgType.equals(SubmessageType.unknown);
+
+      check(Message.fromJson(
+        (deepToJson(dmMessage) as Map<String, dynamic>)
+          ..['submessages'] = [submessage..['message_id'] = dmMessage.id],
+      )).submessages.single.msgType.equals(SubmessageType.unknown);
+    });
+
+    test('submessage content gets decoded from JSON', () {
+      final streamMessage = eg.streamMessage(sender: eg.selfUser);
+      final expected = {
+        'widget_type': 'poll',
+        'extra_data': {
+          'question': 'favorite letter',
+          'options': ['A', 'B', 'C'],
+        }
+      };
+      final submessage = {
+        'msg_type': 'unknown_widget',
+        'content': const JsonEncoder().convert(expected),
+        'message_id': streamMessage.id,
+        'sender_id': eg.selfUser.userId,
+        'id': 1,
+      };
+
+      check(Message.fromJson(
+        (deepToJson(streamMessage) as Map<String, dynamic>)
+          ..['submessages'] = [submessage]
+      )).submessages.single.content.isA<Map<String, Object?>>()
+        .deepEquals(expected);
+    });
+
     // Code relevant to messageEditState is tested separately in the
     // MessageEditState group.
   });