ui: Distinguish isBot: true users with a bot marker

Fixes: zulip#156

Author: sm-sayedi

lib/widgets/message_list.dart

@@ -897,6 +897,8 @@ class MessageWithPossibleSender extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final message = item.message;
+    final messageSender =
+      PerAccountStoreWidget.of(context).users[message.senderId];
 
     Widget? senderRow;
     if (item.showSender) {
@@ -926,6 +928,10 @@ class MessageWithPossibleSender extends StatelessWidget {
                       ).merge(weightVariableTextStyle(context, wght: 600,
                                 wghtIfPlatformRequestsBold: 900)),
                       overflow: TextOverflow.ellipsis)),
+                  if (messageSender?.isBot ?? false) ...[
+                    const SizedBox(width: 8),
+                    const Icon(ZulipIcons.bot, size: 18, color: Colors.grey),
+                  ],
                 ]))),
           const SizedBox(width: 4),
           Text(time,

test/example_data.dart

@@ -60,6 +60,7 @@ User user({
   String? email,
   String? fullName,
   bool? isActive,
+  bool? isBot,
   String? avatarUrl,
   Map<int, ProfileFieldUserData>? profileData,
 }) {
@@ -74,7 +75,7 @@ User user({
     isAdmin: false,
     isGuest: false,
     isBillingAdmin: false,
-    isBot: false,
+    isBot: isBot ?? false,
     botType: null,
     botOwnerId: null,
     role: UserRole.member,

test/widgets/message_list_test.dart

@@ -30,6 +30,7 @@ import '../model/unreads_checks.dart';
 import '../stdlib_checks.dart';
 import '../test_images.dart';
 import 'content_checks.dart';
+import 'content_test.dart';
 import 'dialog_checks.dart';
 
 void main() {
@@ -44,6 +45,7 @@ void main() {
     int? messageCount,
     List<Message>? messages,
     List<ZulipStream>? streams,
+    List<User>? users,
     List<Subscription>? subscriptions,
     UnreadMessagesSnapshot? unreadMsgs,
   }) async {
@@ -56,6 +58,7 @@ void main() {
 
     // prepare message list data
     store.addUser(eg.selfUser);
+    store.addUsers(users ?? []);
     assert((messageCount == null) != (messages == null));
     messages ??= List.generate(messageCount!, (index) {
       return eg.streamMessage(sender: eg.selfUser);
@@ -484,6 +487,22 @@ void main() {
 
       debugNetworkImageHttpClientProvider = null;
     });
+
+    testWidgets('Bot user is distinguished by showing an icon', (tester) async {
+      prepareBoringImageHttpClient();
+
+      final users = List.generate(3, (index) => eg.user(isBot: index == 0));
+
+      await setupMessageListPage(
+        tester,
+        messages: users.map((user) => eg.streamMessage(sender: user)).toList(),
+        users: users,
+      );
+
+      tester.widget(find.byIcon(ZulipIcons.bot));
+
+      debugNetworkImageHttpClientProvider = null;
+    });
   });
 
   group('Starred messages', () {