Merge PR #1583: optimize extension API loading

# Conflicts:
#	ui/flutter/lib/features/extensions/presentation/widgets/extension_detail_view.dart

ui/flutter/lib/api/gopeed_site_api.dart

@@ -11,6 +11,8 @@ class GopeedSiteApi {
   static final instance = GopeedSiteApi._();
 
   static const _host = 'gopeed.com';
+  final _storePages = <String, ({StoreExtensionPage page, DateTime expires})>{};
+  final _storeRequests = <String, Future<StoreExtensionPage>>{};
 
   Future<List<dynamic>> getReleases({int perPage = 10}) async {
     final json = await _getJson('/api/releases', queryParameters: {'per_page': perPage.clamp(1, 100).toString()});
@@ -26,20 +28,52 @@ class GopeedSiteApi {
     StoreExtensionSort sort = StoreExtensionSort.stars,
     StoreSortOrder order = StoreSortOrder.desc,
     String? query,
+    bool forceRefresh = false,
   }) async {
-    final json = await _getJson(
-      '/api/extensions',
-      queryParameters: {
-        'page': page.toString(),
-        'limit': limit.clamp(1, 100).toString(),
-        'sort': sort.name,
-        'order': order.name,
-        if (query != null && query.trim().isNotEmpty) 'q': query.trim(),
-      },
-    );
+    final params = {
+      'page': page.toString(),
+      'limit': limit.clamp(1, 100).toString(),
+      'sort': sort.name,
+      'order': order.name,
+      'view': 'summary',
+      if (query != null && query.trim().isNotEmpty) 'q': query.trim(),
+    };
+    final key = Uri.https(_host, '/api/extensions', params).toString();
+    final now = DateTime.now();
+    _storePages.removeWhere((_, entry) => !now.isBefore(entry.expires));
+    final cached = _storePages[key];
+    if (!forceRefresh && cached != null) return cached.page;
+    final pending = _storeRequests[key];
+    if (pending != null) return pending;
+    final request = _fetchStorePage(params);
+    _storeRequests[key] = request;
+    try {
+      final result = await request;
+      if (_storePages.length >= 32) _storePages.remove(_storePages.keys.first);
+      _storePages[key] = (page: result, expires: DateTime.now().add(const Duration(minutes: 2)));
+      return result;
+    } finally {
+      _storeRequests.remove(key);
+    }
+  }
+
+  Future<StoreExtensionPage> _fetchStorePage(Map<String, String> params) async {
+    final json = await _getJson('/api/extensions', queryParameters: params);
     return StoreExtensionPage.fromJson(json as Map<String, dynamic>);
   }
 
+  Future<StoreExtension> getExtension(String id, {String? version}) async {
+    final json = await _getJsonUri(
+      Uri(
+        scheme: 'https',
+        host: _host,
+        pathSegments: ['api', 'extensions', id],
+        queryParameters: {if (version != null && version.isNotEmpty) 'version': version},
+      ),
+    );
+    return StoreExtension.fromJson(json as Map<String, dynamic>);
+  }
+
   Future<void> reportExtensionInstall(String id) async {
     final uri = Uri.https(_host, '/api/extensions/install');
     await proxyRequest(
@@ -49,8 +83,11 @@ class GopeedSiteApi {
     );
   }
 
-  Future<dynamic> _getJson(String path, {Map<String, String>? queryParameters}) async {
-    final uri = Uri.https(_host, path, queryParameters);
+  Future<dynamic> _getJson(String path, {Map<String, String>? queryParameters}) {
+    return _getJsonUri(Uri.https(_host, path, queryParameters));
+  }
+
+  Future<dynamic> _getJsonUri(Uri uri) async {
     final Response<String> response = await proxyRequest(uri.toString());
     if (response.data == null || response.data!.isEmpty) {
       throw Exception('Empty response from $uri');

ui/flutter/lib/api/model/store_extension.dart

@@ -64,6 +64,7 @@ class StoreExtension {
   final List<String> topics;
   final DateTime? createdAt;
   final DateTime? updatedAt;
+  final bool hasDetails;
 
   StoreExtension({
     required this.id,
@@ -84,6 +85,7 @@ class StoreExtension {
     required this.topics,
     this.createdAt,
     this.updatedAt,
+    this.hasDetails = true,
   });
 
   factory StoreExtension.fromJson(Map<String, dynamic> json) {
@@ -106,6 +108,7 @@ class StoreExtension {
       topics: _parseTopics(json['topics']),
       createdAt: _parseDate(json['createdAt']),
       updatedAt: _parseDate(json['updatedAt']),
+      hasDetails: json.containsKey('readme'),
     );
   }
 

ui/flutter/lib/features/extensions/application/extensions_controller.dart

@@ -3,13 +3,13 @@ import 'dart:collection';
 
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
-import '../../../api/gopeed_site_api.dart';
 import '../../../api/model/extension.dart';
 import '../../../api/model/install_extension.dart';
 import '../../../api/model/store_extension.dart';
 import '../../../api/model/switch_extension.dart';
 import '../../../api/model/update_extension_settings.dart';
 import '../../../core/capabilities/app_capabilities.dart';
+import 'store_extension_details_provider.dart';
 
 final extensionsControllerProvider = AsyncNotifierProvider<ExtensionsController, ExtensionsState>(
   ExtensionsController.new,
@@ -121,63 +121,81 @@ class ExtensionsState {
 class ExtensionsController extends AsyncNotifier<ExtensionsState> {
   static const manualInstallBusyKey = '__manual_install__';
   int _devModeCount = 0;
+  int _installedRevision = 0;
+  int _storeRevision = 0;
+  Future<void>? _updateCheck;
+  bool _checkUpdatesAgain = false;
 
   @override
-  Future<ExtensionsState> build() async {
-    var next = const ExtensionsState(loadingInstalled: true, loadingStore: true);
+  Future<ExtensionsState> build() => _loadInitialData();
+
+  Future<ExtensionsState> _loadInitialData({bool forceRefresh = false}) async {
+    final next = _current.copyWith(loadingInstalled: true, loadingStore: true);
     state = AsyncValue.data(next);
-    final installed = await _loadInstalled(refreshUpdates: true, current: next);
-    next = state.value ?? installed;
-    await _refreshStore(current: next);
-    return state.value ?? next;
+    await Future.wait([
+      _loadInstalled(refreshUpdates: true, current: next),
+      _refreshStore(current: _current, forceRefresh: forceRefresh),
+    ]);
+    return ref.mounted ? _current : next;
   }
 
   Future<void> loadInitialData() async {
-    state = const AsyncValue.loading();
-    state = AsyncValue.data(await build());
+    await _loadInitialData(forceRefresh: true);
   }
 
   Future<void> loadInstalled({bool refreshUpdates = false}) async {
+    if (!ref.mounted) return;
     await _loadInstalled(refreshUpdates: refreshUpdates, current: _current.copyWith(loadingInstalled: true));
   }
 
   Future<void> refreshStore() async {
-    await _refreshStore(current: _current.copyWith(loadingStore: true));
+    await _refreshStore(current: _current.copyWith(loadingStore: true), forceRefresh: true);
   }
 
   Future<void> loadMoreStore() async {
     final current = _current;
     final pagination = current.storePagination;
     if (pagination == null || !pagination.hasNext || current.loadingMoreStore) return;
+    final revision = _storeRevision;
     state = AsyncValue.data(current.copyWith(loadingMoreStore: true));
     try {
-      final page = await GopeedSiteApi.instance.getExtensions(
-        page: pagination.page + 1,
-        limit: pagination.limit,
-        sort: current.storeSort,
-        query: current.storeQuery,
-      );
+      final page = await ref
+          .read(gopeedSiteApiProvider)
+          .getExtensions(
+            page: pagination.page + 1,
+            limit: pagination.limit,
+            sort: current.storeSort,
+            query: current.storeQuery,
+          );
+      if (!ref.mounted || revision != _storeRevision) return;
       state = AsyncValue.data(
         _current.copyWith(
-          storeExtensions: [..._current.storeExtensions, ...page.data],
+          // Cached pages can briefly overlap when stars/install counts change.
+          storeExtensions: {
+            for (final extension in _current.storeExtensions) extension.id: extension,
+            for (final extension in page.data) extension.id: extension,
+          }.values.toList(),
           storePagination: page.pagination,
           loadingMoreStore: false,
         ),
       );
     } catch (_) {
+      if (!ref.mounted || revision != _storeRevision) return;
       state = AsyncValue.data(_current.copyWith(loadingMoreStore: false));
       rethrow;
     }
   }
 
   Future<void> searchStore(String query) async {
+    if (query.trim() == _current.storeQuery) return;
     state = AsyncValue.data(_current.copyWith(storeQuery: query.trim()));
-    await refreshStore();
+    await _refreshStore(current: _current);
   }
 
   Future<void> changeSort(StoreExtensionSort sort) async {
+    if (sort == _current.storeSort) return;
     state = AsyncValue.data(_current.copyWith(storeSort: sort));
-    await refreshStore();
+    await _refreshStore(current: _current);
   }
 
   void changeFilter(ExtensionListFilter filter) {
@@ -257,23 +275,43 @@ class ExtensionsController extends AsyncNotifier<ExtensionsState> {
     });
   }
 
-  Future<void> checkUpdate() async {
-    final flags = <String, String>{};
-    for (final ext in _current.installedExtensions) {
-      try {
-        final resp = await ref.read(gopeedServiceProvider).upgradeCheckExtension(ext.identity);
-        if (resp.newVersion.isNotEmpty) {
-          flags[ext.identity] = resp.newVersion;
+  Future<void> checkUpdate() {
+    if (!ref.mounted) return Future.value();
+    _checkUpdatesAgain = true;
+    // Installation/refresh can request a fresh scan while one is running.
+    // Coalesce those requests instead of launching overlapping Git operations.
+    return _updateCheck ??= _runUpdateChecks().whenComplete(() => _updateCheck = null);
+  }
+
+  Future<void> _runUpdateChecks() async {
+    final service = ref.read(gopeedServiceProvider);
+    while (ref.mounted && _checkUpdatesAgain) {
+      _checkUpdatesAgain = false;
+      final revision = _installedRevision;
+      final installed = List<Extension>.of(_current.installedExtensions);
+      final flags = <String, String>{};
+      for (final ext in installed) {
+        if (!ref.mounted) return;
+        if (revision != _installedRevision) break;
+        try {
+          final resp = await service.upgradeCheckExtension(ext.identity);
+          if (!ref.mounted) return;
+          if (revision != _installedRevision) break;
+          if (resp.newVersion.isNotEmpty) flags[ext.identity] = resp.newVersion;
+        } catch (_) {
+          // A failed update check must never prevent loading the store.
         }
-      } catch (_) {}
+      }
+      if (ref.mounted && revision == _installedRevision) {
+        state = AsyncValue.data(_current.copyWith(updateFlags: flags));
+      }
     }
-    state = AsyncValue.data(_current.copyWith(updateFlags: flags));
   }
 
   void tryOpenDevMode() {
     if (_devModeCount == 0) {
       Future.delayed(const Duration(seconds: 2), () {
-        if (_current.devMode) return;
+        if (!ref.mounted || _current.devMode) return;
         _devModeCount = 0;
       });
     }
@@ -286,26 +324,40 @@ class ExtensionsController extends AsyncNotifier<ExtensionsState> {
   ExtensionsState get _current => state.value ?? const ExtensionsState();
 
   Future<ExtensionsState> _loadInstalled({required bool refreshUpdates, required ExtensionsState current}) async {
+    final revision = ++_installedRevision;
     state = AsyncValue.data(current.copyWith(loadingInstalled: true));
     final installed = await ref.read(gopeedServiceProvider).getExtensions();
+    if (!ref.mounted) return current;
+    if (revision != _installedRevision) return _current;
     state = AsyncValue.data(_current.copyWith(installedExtensions: installed, loadingInstalled: false));
     if (refreshUpdates) {
-      await checkUpdate();
+      unawaited(checkUpdate());
     }
     return _current;
   }
 
-  Future<void> _refreshStore({required ExtensionsState current}) async {
-    state = AsyncValue.data(current.copyWith(loadingStore: true));
-    final page = await GopeedSiteApi.instance.getExtensions(
-      page: 1,
-      limit: 20,
-      sort: _current.storeSort,
-      query: _current.storeQuery,
-    );
-    state = AsyncValue.data(
-      _current.copyWith(storeExtensions: page.data, storePagination: page.pagination, loadingStore: false),
-    );
+  Future<void> _refreshStore({required ExtensionsState current, bool forceRefresh = false}) async {
+    final revision = ++_storeRevision;
+    state = AsyncValue.data(current.copyWith(loadingStore: true, loadingMoreStore: false));
+    try {
+      final page = await ref
+          .read(gopeedSiteApiProvider)
+          .getExtensions(
+            page: 1,
+            limit: 20,
+            sort: current.storeSort,
+            query: current.storeQuery,
+            forceRefresh: forceRefresh,
+          );
+      if (!ref.mounted || revision != _storeRevision) return;
+      state = AsyncValue.data(
+        _current.copyWith(storeExtensions: page.data, storePagination: page.pagination, loadingStore: false),
+      );
+    } catch (_) {
+      if (!ref.mounted || revision != _storeRevision) return;
+      state = AsyncValue.data(_current.copyWith(loadingStore: false));
+      rethrow;
+    }
   }
 
   Future<void> _runBusy(String id, Future<void> Function() action) async {
@@ -314,12 +366,15 @@ class ExtensionsController extends AsyncNotifier<ExtensionsState> {
     try {
       await action();
     } finally {
-      final busy = Set<String>.of(_current.busyExtensionIds)..remove(id);
-      state = AsyncValue.data(_current.copyWith(busyExtensionIds: busy));
+      if (ref.mounted) {
+        final busy = Set<String>.of(_current.busyExtensionIds)..remove(id);
+        state = AsyncValue.data(_current.copyWith(busyExtensionIds: busy));
+      }
     }
   }
 
   void _bumpStoreInstallCount(String id) {
+    if (!ref.mounted) return;
     final current = _current;
     final index = current.storeExtensions.indexWhere((e) => e.id == id);
     if (index < 0) return;
@@ -344,14 +399,17 @@ class ExtensionsController extends AsyncNotifier<ExtensionsState> {
       topics: ext.topics,
       createdAt: ext.createdAt,
       updatedAt: ext.updatedAt,
+      hasDetails: ext.hasDetails,
     );
     state = AsyncValue.data(current.copyWith(storeExtensions: updated));
   }
 
   void _reportInstallSafe(String id) {
+    if (!ref.mounted) return;
+    final siteApi = ref.read(gopeedSiteApiProvider);
     unawaited(() async {
       try {
-        await GopeedSiteApi.instance.reportExtensionInstall(id);
+        await siteApi.reportExtensionInstall(id);
       } catch (_) {}
     }());
   }

ui/flutter/lib/features/extensions/application/store_extension_details_provider.dart

@@ -0,0 +1,25 @@
+import 'dart:async';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../api/gopeed_site_api.dart';
+import '../../../api/model/store_extension.dart';
+
+final gopeedSiteApiProvider = Provider<GopeedSiteApi>((ref) => GopeedSiteApi.instance);
+
+typedef StoreExtensionDetailsKey = ({String id, String version});
+
+// A shared future deduplicates drawer/page requests. Successful details survive
+// closing the view, while failures can be retried and new versions get a new key.
+final storeExtensionDetailsProvider = FutureProvider.autoDispose.family<StoreExtension, StoreExtensionDetailsKey>((
+  ref,
+  key,
+) async {
+  final extension = await ref.watch(gopeedSiteApiProvider).getExtension(key.id, version: key.version);
+  if (ref.mounted) {
+    final keepAlive = ref.keepAlive();
+    final expiry = Timer(const Duration(minutes: 30), keepAlive.close);
+    ref.onDispose(expiry.cancel);
+  }
+  return extension;
+});

ui/flutter/lib/features/extensions/presentation/widgets/extension_detail_view.dart

@@ -19,6 +19,7 @@ import '../../../../shared/widgets/app_toast.dart';
 import '../../../../shared/widgets/detail/app_detail_surface.dart';
 import '../../../../util/util.dart';
 import '../../application/extensions_controller.dart';
+import '../../application/store_extension_details_provider.dart';
 import 'extension_icon.dart';
 import 'extension_update_dialog.dart';
 import 'extension_update_status.dart';
@@ -63,7 +64,13 @@ class ExtensionDetailView extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final palette = AppPalette.of(context);
     final state = ref.watch(extensionsControllerProvider).value;
-    final current = state?.findItem(item.id) ?? item;
+    final summary = state?.findItem(item.id) ?? item;
+    final summaryStore = summary.store;
+    final detailKey = summaryStore == null || summaryStore.hasDetails
+        ? null
+        : (id: summaryStore.id, version: summaryStore.version);
+    final details = detailKey == null ? null : ref.watch(storeExtensionDetailsProvider(detailKey));
+    final current = ExtensionListItem(installed: summary.installed, store: details?.value ?? summaryStore);
     final installed = current.installed;
     final store = current.store;
     final busy = state?.busyExtensionIds.contains(current.id) ?? false;
@@ -116,7 +123,7 @@ class ExtensionDetailView extends ConsumerWidget {
                         'v${current.version}',
                         style: TextStyle(color: palette.textMuted, fontSize: 11.5, fontWeight: FontWeight.w600),
                       ),
-                      if (store != null) _ExtensionStats(store: store),
+                      if (summaryStore != null) _ExtensionStats(store: summaryStore),
                     ],
                   ),
                 ],
@@ -164,6 +171,21 @@ class ExtensionDetailView extends ConsumerWidget {
               ),
           ],
         ),
+        if (details?.isLoading == true)
+          const Padding(
+            key: ValueKey('extension-details-loading'),
+            padding: EdgeInsets.only(top: 24),
+            child: Center(child: shad.CircularProgressIndicator()),
+          ),
+        if (details?.hasError == true && detailKey != null)
+          Padding(
+            padding: const EdgeInsets.only(top: 24),
+            child: shad.SecondaryButton(
+              key: const ValueKey('extension-details-retry'),
+              onPressed: () => ref.invalidate(storeExtensionDetailsProvider(detailKey)),
+              child: Text(context.l10n.retry),
+            ),
+          ),
         if (store != null) ...[SizedBox(height: mobile ? 24 : 28), _ExtensionReadme(item: current, mobile: mobile)],
       ],
     );
@@ -206,6 +228,7 @@ class _ExtensionReadmeState extends State<_ExtensionReadme> {
     final previous = oldWidget.item.installed;
     final current = widget.item.installed;
     if (previous?.identity != current?.identity ||
+        oldWidget.item.id != widget.item.id ||
         previous?.devMode != current?.devMode ||
         previous?.devPath != current?.devPath ||
         oldWidget.item.store?.readme != widget.item.store?.readme) {

ui/flutter/test/api/gopeed_site_api_test.dart

@@ -0,0 +1,78 @@
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:dio/dio.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gopeed/api/api.dart' as api;
+import 'package:gopeed/api/gopeed_site_api.dart';
+import 'package:gopeed/core/network/gopeed/gopeed_transport.dart';
+
+void main() {
+  test('summary requests are shared and cached; explicit refresh requests fresh data', () async {
+    final pending = Completer<Response<String>>();
+    final transport = _Transport()..onProxy = (_) => pending.future;
+    api.setTransportForTesting(transport);
+    final site = GopeedSiteApi.instance;
+    final first = site.getExtensions(query: 'cache-test', forceRefresh: true);
+    final second = site.getExtensions(query: 'cache-test');
+    expect(transport.urls.length, 1);
+    expect(Uri.parse(transport.urls.single).queryParameters['view'], 'summary');
+    pending.complete(
+      _response({
+        'data': [
+          {'id': 'test'},
+        ],
+      }),
+    );
+    expect((await first).data.single.hasDetails, isFalse);
+    await second;
+    await site.getExtensions(query: 'cache-test');
+    expect(transport.urls.length, 1);
+    await site.getExtensions(query: 'cache-test', forceRefresh: true);
+    expect(transport.urls.length, 2);
+  });
+
+  test('failed lists are not cached', () async {
+    final transport = _Transport()..onProxy = (_) => Future.error(StateError('offline'));
+    api.setTransportForTesting(transport);
+    final site = GopeedSiteApi.instance;
+    await expectLater(site.getExtensions(query: 'error-test'), throwsStateError);
+    transport.onProxy = (_) async => _response({
+      'data': [
+        {'id': 'recovered'},
+      ],
+    });
+    expect((await site.getExtensions(query: 'error-test')).data.single.id, 'recovered');
+    expect(transport.urls.length, 2);
+  });
+
+  test('detail IDs are encoded once and a null README is still loaded detail', () async {
+    final transport = _Transport()..onProxy = (_) async => _response({'id': '开发者@name', 'readme': null});
+    api.setTransportForTesting(transport);
+    final result = await GopeedSiteApi.instance.getExtension('开发者@name', version: '1.2.3');
+    final uri = Uri.parse(transport.urls.single);
+    expect(uri.pathSegments, ['api', 'extensions', '开发者@name']);
+    expect(uri.queryParameters['version'], '1.2.3');
+    expect(result.hasDetails, isTrue);
+  });
+}
+
+Response<String> _response(Map<String, dynamic> json) => Response(
+  requestOptions: RequestOptions(path: '/test'),
+  data: jsonEncode(json),
+  statusCode: 200,
+);
+
+class _Transport implements GopeedTransport {
+  final urls = <String>[];
+  Future<Response<String>> Function(String) onProxy = (_) async => _response({'data': []});
+
+  @override
+  Future<Response<String>> proxyRequest(String uri, {dynamic data, Options? options}) {
+    urls.add(uri);
+    return onProxy(uri);
+  }
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}

ui/flutter/test/features/extensions/application/extensions_controller_test.dart

@@ -0,0 +1,234 @@
+import 'dart:async';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gopeed/api/gopeed_site_api.dart';
+import 'package:gopeed/api/model/extension.dart';
+import 'package:gopeed/api/model/store_extension.dart';
+import 'package:gopeed/api/model/update_check_extension_resp.dart';
+import 'package:gopeed/core/capabilities/app_capabilities.dart';
+import 'package:gopeed/core/capabilities/capability_rpc.dart';
+import 'package:gopeed/core/capabilities/gopeed_capability.dart';
+import 'package:gopeed/features/extensions/application/extensions_controller.dart';
+import 'package:gopeed/features/extensions/application/store_extension_details_provider.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  test('store loads while installed data and update checks are still pending', () async {
+    final installed = Completer<List<Extension>>();
+    final update = Completer<UpdateCheckExtensionResp>();
+    var updateCalls = 0;
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getExtensions, (_) => installed.future)
+      ..bind(GopeedMethods.checkExtensionUpdate, (_) {
+        updateCalls++;
+        return update.future;
+      });
+    final site = _SiteApi();
+    final container = _container(registry, site);
+    final subscription = container.listen(extensionsControllerProvider, (_, _) {});
+    addTearDown(subscription.close);
+
+    await _settle();
+    expect(site.listCalls, 1);
+    expect(container.read(extensionsControllerProvider).value?.storeExtensions.single.id, 'market');
+    expect(container.read(extensionsControllerProvider).value?.loadingStore, isFalse);
+    expect(updateCalls, 0);
+
+    installed.complete([_installed()]);
+    await _settle();
+    expect(updateCalls, 1);
+    expect(container.read(extensionsControllerProvider).value?.loadingInstalled, isFalse);
+    expect(container.read(extensionsControllerProvider).value?.storeExtensions.single.id, 'market');
+    update.complete(UpdateCheckExtensionResp(newVersion: '2.0.0'));
+    await _settle();
+    expect(container.read(extensionsControllerProvider).value?.updateFlags, {'gopeed@test': '2.0.0'});
+  });
+
+  test('a stale update scan cannot restore flags after installed data changes', () async {
+    var installed = [_installed()];
+    final update = Completer<UpdateCheckExtensionResp>();
+    var updateCalls = 0;
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getExtensions, (_) => installed)
+      ..bind(GopeedMethods.checkExtensionUpdate, (_) {
+        updateCalls++;
+        return update.future;
+      });
+    final container = _container(registry, _SiteApi());
+    final controller = container.read(extensionsControllerProvider.notifier);
+    await _settle();
+    final running = controller.checkUpdate();
+    expect(updateCalls, 1);
+    installed = [];
+    await controller.loadInstalled();
+    update.complete(UpdateCheckExtensionResp(newVersion: '2.0.0'));
+    await running;
+    expect(container.read(extensionsControllerProvider).value?.installedExtensions, isEmpty);
+    expect(container.read(extensionsControllerProvider).value?.updateFlags, isEmpty);
+  });
+
+  test('an update scan can finish after the controller is disposed', () async {
+    final update = Completer<UpdateCheckExtensionResp>();
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getExtensions, (_) => [_installed()])
+      ..bind(GopeedMethods.checkExtensionUpdate, (_) => update.future);
+    final container = _container(registry, _SiteApi());
+    final controller = container.read(extensionsControllerProvider.notifier);
+    await _settle();
+    final running = controller.checkUpdate();
+    container.dispose();
+    update.complete(UpdateCheckExtensionResp(newVersion: '2.0.0'));
+    await running;
+  });
+
+  test('old search results cannot replace a newer search', () async {
+    final old = Completer<StoreExtensionPage>();
+    final latest = Completer<StoreExtensionPage>();
+    final site = _SiteApi()
+      ..onList = (query) => switch (query) {
+        'old' => old.future,
+        'new' => latest.future,
+        _ => Future.value(_page('market')),
+      };
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getExtensions, (_) => <Extension>[]);
+    final container = _container(registry, site);
+    final controller = container.read(extensionsControllerProvider.notifier);
+    await _settle();
+    final first = controller.searchStore('old');
+    final second = controller.searchStore('new');
+    latest.complete(_page('new-result'));
+    await second;
+    old.complete(_page('old-result'));
+    await first;
+    final state = container.read(extensionsControllerProvider).value!;
+    expect(state.storeQuery, 'new');
+    expect(state.storeExtensions.single.id, 'new-result');
+    expect(state.loadingStore, isFalse);
+  });
+
+  test('overlapping cached pages do not duplicate an extension', () async {
+    final site = _SiteApi();
+    site.onList = (_) async => StoreExtensionPage.fromJson({
+      'data': [
+        {'id': 'market', 'version': '1.0.0'},
+        if (site.listCalls > 1) {'id': 'second', 'version': '1.0.0'},
+      ],
+      'pagination': {'page': site.listCalls, 'limit': 20, 'hasNext': site.listCalls == 1},
+    });
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getExtensions, (_) => <Extension>[]);
+    final container = _container(registry, site);
+    final controller = container.read(extensionsControllerProvider.notifier);
+    await _settle();
+    await controller.loadMoreStore();
+    expect(container.read(extensionsControllerProvider).value?.storeExtensions.map((e) => e.id), ['market', 'second']);
+  });
+
+  test('detail requests are shared, cache empty READMEs, and distinguish versions', () async {
+    final detail = Completer<StoreExtension>();
+    final site = _SiteApi()..onDetail = (_, _) => detail.future;
+    final container = ProviderContainer(overrides: [gopeedSiteApiProvider.overrideWithValue(site)]);
+    addTearDown(container.dispose);
+    const key = (id: 'market', version: '1.0.0');
+    final provider = storeExtensionDetailsProvider(key);
+    final subscription = container.listen(provider, (_, _) {});
+    final first = container.read(provider.future);
+    final second = container.read(provider.future);
+    expect(site.detailCalls, 1);
+    detail.complete(StoreExtension.fromJson({'id': 'market', 'version': '1.0.0', 'readme': null}));
+    expect((await first).hasDetails, isTrue);
+    await second;
+    subscription.close();
+    await _settle();
+    await container.read(provider.future);
+    expect(site.detailCalls, 1);
+    await container.read(storeExtensionDetailsProvider((id: 'market', version: '2.0.0')).future);
+    expect(site.detailCalls, 2);
+  });
+
+  test('failed details can be retried', () async {
+    final site = _SiteApi()..onDetail = (_, _) => Future.error(StateError('offline'));
+    final container = ProviderContainer(overrides: [gopeedSiteApiProvider.overrideWithValue(site)]);
+    addTearDown(container.dispose);
+    final provider = storeExtensionDetailsProvider((id: 'market', version: '1.0.0'));
+    final subscription = container.listen(provider, (_, _) {});
+    addTearDown(subscription.close);
+    await expectLater(container.read(provider.future), throwsStateError);
+    site.onDetail = (_, _) async => StoreExtension.fromJson({'id': 'market', 'readme': 'loaded'});
+    container.invalidate(provider);
+    expect((await container.read(provider.future)).readme, 'loaded');
+    expect(site.detailCalls, 2);
+  });
+}
+
+ProviderContainer _container(CapabilityRegistry registry, _SiteApi site) {
+  final container = ProviderContainer(
+    overrides: [
+      appCapabilitiesProvider.overrideWithValue(AppCapabilities(LocalCapabilityInvoker(registry))),
+      gopeedSiteApiProvider.overrideWithValue(site),
+    ],
+  );
+  addTearDown(container.dispose);
+  return container;
+}
+
+Future<void> _settle() async {
+  for (var i = 0; i < 5; i++) {
+    await Future<void>.delayed(Duration.zero);
+  }
+}
+
+StoreExtensionPage _page(String id) => StoreExtensionPage.fromJson({
+  'data': [
+    {'id': id, 'version': '1.0.0'},
+  ],
+  'pagination': {'page': 1, 'limit': 20, 'total': 1, 'totalPages': 1},
+});
+
+Extension _installed() => Extension(
+  identity: 'gopeed@test',
+  name: 'test',
+  author: 'gopeed',
+  title: 'Test',
+  description: '',
+  icon: '',
+  version: '1.0.0',
+  homepage: '',
+  repository: null,
+  disabled: false,
+  devMode: false,
+  devPath: '',
+);
+
+class _SiteApi implements GopeedSiteApi {
+  var listCalls = 0;
+  var detailCalls = 0;
+  Future<StoreExtensionPage> Function(String?) onList = (_) async => _page('market');
+  Future<StoreExtension> Function(String, String?) onDetail = (id, _) async =>
+      StoreExtension.fromJson({'id': id, 'readme': null});
+
+  @override
+  Future<StoreExtensionPage> getExtensions({
+    int page = 1,
+    int limit = 20,
+    StoreExtensionSort sort = StoreExtensionSort.stars,
+    StoreSortOrder order = StoreSortOrder.desc,
+    String? query,
+    bool forceRefresh = false,
+  }) {
+    listCalls++;
+    return onList(query);
+  }
+
+  @override
+  Future<StoreExtension> getExtension(String id, {String? version}) {
+    detailCalls++;
+    return onDetail(id, version);
+  }
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}

ui/flutter/test/features/extensions/presentation/widgets/extension_detail_loading_test.dart

@@ -0,0 +1,89 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gopeed/api/gopeed_site_api.dart';
+import 'package:gopeed/api/model/store_extension.dart';
+import 'package:gopeed/features/extensions/application/extensions_controller.dart';
+import 'package:gopeed/features/extensions/application/store_extension_details_provider.dart';
+import 'package:gopeed/features/extensions/presentation/widgets/extension_detail_view.dart';
+import 'package:gopeed/shared/theme/app_theme.dart';
+import 'package:shadcn_flutter/shadcn_flutter.dart' as shad;
+
+void main() {
+  for (final width in [390.0, 1024.0]) {
+    testWidgets('summary details load and can retry at width $width', (tester) async {
+      tester.view.physicalSize = Size(width, 844);
+      tester.view.devicePixelRatio = 1;
+      addTearDown(tester.view.resetPhysicalSize);
+      addTearDown(tester.view.resetDevicePixelRatio);
+      final pending = Completer<StoreExtension>();
+      final site = _DetailApi()..request = pending.future;
+      await tester.pumpWidget(
+        ProviderScope(
+          overrides: [
+            extensionsControllerProvider.overrideWith(_SummaryController.new),
+            gopeedSiteApiProvider.overrideWithValue(site),
+          ],
+          child: shad.ShadcnApp(
+            theme: AppTheme.light(),
+            materialTheme: AppTheme.materialLight(),
+            home: shad.Scaffold(
+              child: ExtensionDetailView(
+                item: ExtensionListItem(store: _summary()),
+                mobile: width < 600,
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pump();
+      expect(find.byKey(const ValueKey('extension-details-loading')), findsOneWidget);
+      expect(find.byKey(const ValueKey('extension-details-install')), findsOneWidget);
+      pending.completeError(StateError('offline'));
+      await tester.pump();
+      await tester.pump();
+      expect(find.byKey(const ValueKey('extension-details-retry')), findsOneWidget);
+      site.request = Future.value(
+        StoreExtension.fromJson({
+          'id': 'market',
+          'title': 'Market',
+          'version': '1.0.0',
+          'readme': '# Loaded details',
+          'homepage': 'https://example.com',
+        }),
+      );
+      await tester.tap(find.byKey(const ValueKey('extension-details-retry')));
+      await tester.pumpAndSettle();
+      expect(find.text('Loaded details'), findsOneWidget);
+      expect(find.byKey(const ValueKey('extension-details-homepage')), findsOneWidget);
+      expect(find.byKey(const ValueKey('extension-details-retry')), findsNothing);
+      expect(tester.takeException(), isNull);
+      await tester.pumpWidget(const SizedBox.shrink());
+      await tester.pump();
+    });
+  }
+}
+
+StoreExtension _summary() => StoreExtension.fromJson({
+  'id': 'market',
+  'title': 'Market',
+  'version': '1.0.0',
+  'repoUrl': 'https://github.com/test/repo',
+});
+
+class _SummaryController extends ExtensionsController {
+  @override
+  Future<ExtensionsState> build() async => ExtensionsState(storeExtensions: [_summary()]);
+}
+
+class _DetailApi implements GopeedSiteApi {
+  late Future<StoreExtension> request;
+
+  @override
+  Future<StoreExtension> getExtension(String id, {String? version}) => request;
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}