action: Add dialog to markNarrowAsRead for CombinedFeedNarrow view

A confirm ActionDialog is added to prevent accidentally marking many
messages as read in a non-conversation view.

Also, adjust existing MarkAsReadWidget tests to account for the
added confirmation dialog.

Fixes: #1858

Author: chungwwei

lib/widgets/actions.dart

@@ -32,6 +32,17 @@ abstract final class ZulipAction {
   static Future<void> markNarrowAsRead(BuildContext context, Narrow narrow) async {
     final zulipLocalizations = ZulipLocalizations.of(context);
 
+    if (narrow is CombinedFeedNarrow) {
+      final didConfirm = showSuggestedActionDialog(context: context,
+        title: zulipLocalizations.markAllAsReadConfirmationDialogTitle,
+        message: zulipLocalizations.markAllAsReadConfirmationDialogMessage,
+        actionButtonText: zulipLocalizations.markAllAsReadConfirmationDialogAction,
+      );
+
+      if (await didConfirm.result != true) return;
+      if (!context.mounted) return;
+    }
+
     final didPass = await updateMessageFlagsStartingFromAnchor(
       context: context,
       // Include `is:unread` in the narrow.  That has a database index, so

test/widgets/actions_test.dart

@@ -108,9 +108,7 @@ void main() {
           processedCount: 11, updatedCount: 3,
           firstProcessedId: null, lastProcessedId: null,
           foundOldest: true, foundNewest: true).toJson());
-        final future = ZulipAction.markNarrowAsRead(context, narrow);
-        await tester.pump(Duration.zero);
-        await future;
+        await confirmToMarkNarrowAsRead(tester: tester, context: context, narrow: narrow);
         check(connection.lastRequest).isA<http.Request>()
           ..method.equals('POST')
           ..url.path.equals('/api/v1/messages/flags/narrow')
@@ -134,9 +132,7 @@ void main() {
           processedCount: 11, updatedCount: 3,
           firstProcessedId: null, lastProcessedId: null,
           foundOldest: true, foundNewest: true).toJson());
-        final future = ZulipAction.markNarrowAsRead(context, narrow);
-        await tester.pump(Duration.zero);
-        await future;
+        await confirmToMarkNarrowAsRead(tester: tester, context: context, narrow: narrow);
         check(store.unreads.oldUnreadsMissing).isFalse();
       });
     });

test/widgets/message_list_test.dart

@@ -1171,6 +1171,9 @@ void main() {
           firstProcessedId: null, lastProcessedId: null,
           foundOldest: true, foundNewest: true).toJson());
         await tester.tap(find.byType(MarkAsReadWidget));
+        await tester.pump();
+        final (confirmButton, _) = checkConfirmDialog(tester);
+        await tester.tap(find.byWidget(confirmButton));
         await tester.pumpAndSettle();
         check(store.unreads.oldUnreadsMissing).isFalse();
       });
@@ -1184,6 +1187,9 @@ void main() {
 
         connection.prepare(httpException: http.ClientException('Oops'));
         await tester.tap(find.byType(MarkAsReadWidget));
+        await tester.pump();
+        final (confirmButton, _) = checkConfirmDialog(tester);
+        await tester.tap(find.byWidget(confirmButton));
         await tester.pumpAndSettle();
         checkErrorDialog(tester,
           expectedTitle: zulipLocalizations.errorMarkAsReadFailedTitle,