feat(chat): load older messages on scroll-to-top (history pagination) (v1.11.0+15)

Repository keeps one live Timeline per room and re-yields on its onUpdate callback (fires for both live events AND requestHistory), not just onSync which never fires for pagination. loadMoreMessages now paginates that same instance; added canLoadMore. Timeline widget requests older history when scrolled within 400px of the oldest end, guarded against re-entry, with a top loading spinner. Verified: widget test drives a drag-to-top and asserts loadMoreMessages fires; live smoke test confirms the onUpdate delivery path (reused by history) still shows new messages after the refactor. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-04 08:44:38 +10:00
parent f9c21fddc4
commit e4aa5277d7
6 changed files with 194 additions and 17 deletions
--- a/test/history_pagination_test.dart
+++ b/test/history_pagination_test.dart
@@ -0,0 +1,104 @@
+// Version: 1.0.0 | Created: 2026-07-04
+// Verifies the chat timeline requests older history when scrolled near the
+// top (oldest end) of the reverse list. Driven through the real widget tree
+// with a fake repository, since Playwright cannot scroll the CanvasKit surface.
+
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:matrix/matrix.dart';
+
+import 'package:m8chat_app/core/network/matrix_client.dart';
+import 'package:m8chat_app/features/chat/data/chat_repository.dart';
+import 'package:m8chat_app/features/chat/domain/message_model.dart';
+import 'package:m8chat_app/features/chat/presentation/chat_controller.dart';
+import 'package:m8chat_app/features/chat/presentation/chat_screen.dart';
+
+class _FakeChatRepository extends ChatRepository {
+  _FakeChatRepository() : super(client: Client('test-client'));
+
+  int loadMoreCalls = 0;
+  bool _hasMore = true;
+
+  @override
+  bool canLoadMore(String roomId) => _hasMore;
+
+  @override
+  Future<void> loadMoreMessages(String roomId) async {
+    loadMoreCalls++;
+    _hasMore = false; // one page then exhausted
+  }
+}
+
+void main() {
+  testWidgets('scrolling to the top requests older history once', (
+    tester,
+  ) async {
+    const roomId = '!paginate:server';
+    final base = DateTime(2026, 7, 4, 8);
+    final messages = [
+      for (var i = 40; i >= 1; i--)
+        MessageModel(
+          eventId: '\$e$i',
+          roomId: roomId,
+          senderId: '@me:server',
+          senderDisplayName: 'Me',
+          timestamp: base.add(Duration(seconds: i)),
+          type: MessageType.text,
+          body: 'Message $i',
+          isMine: true,
+        ),
+    ];
+
+    final repo = _FakeChatRepository();
+
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: [
+          matrixClientProvider.overrideWithValue(Client('test-client')),
+          chatRepositoryProvider.overrideWithValue(repo),
+          chatTimelineProvider(
+            roomId,
+          ).overrideWith((ref) => Stream.value(messages)),
+        ],
+        child: const MaterialApp(home: ChatScreen(roomId: roomId)),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(repo.loadMoreCalls, 0);
+
+    // Confirm the override is actually in effect.
+    final container = ProviderScope.containerOf(
+      tester.element(find.byType(ChatScreen)),
+    );
+    expect(identical(container.read(chatRepositoryProvider), repo), isTrue);
+
+    double offset() => tester
+        .state<ScrollableState>(find.byType(Scrollable).first)
+        .position
+        .pixels;
+    double maxExtent() => tester
+        .state<ScrollableState>(find.byType(Scrollable).first)
+        .position
+        .maxScrollExtent;
+
+    // Scroll up toward the oldest end (reverse list: drag content down).
+    await tester.drag(find.byType(ListView), const Offset(0, 3000));
+    await tester.pumpAndSettle();
+
+    expect(
+      offset(),
+      greaterThan(maxExtent() - 400),
+      reason:
+          'drag should have reached the oldest end (offset=${offset()}, '
+          'max=${maxExtent()})',
+    );
+
+    expect(
+      repo.loadMoreCalls,
+      greaterThan(0),
+      reason: 'reaching the top should request older history',
+    );
+  });
+}