feat: stack action

mobile/lib/domain/services/asset.service.dart

@@ -77,4 +77,22 @@ class AssetService {
     await _apiRepository.updateFavorite(remoteIds, isFavorite);
     await _remoteRepository.updateFavorite(remoteIds, isFavorite);
   }
+
+  Future<void> stack(String userId, List<String> remoteIds) async {
+    if (remoteIds.isEmpty) {
+      return;
+    }
+
+    final stack = await _apiRepository.stack(remoteIds);
+    await _remoteRepository.stack(userId, stack);
+  }
+
+  Future<void> unStack(List<String> stackIds) async {
+    if (stackIds.isEmpty) {
+      return;
+    }
+
+    await _remoteRepository.unStack(stackIds);
+    await _apiRepository.unStack(stackIds);
+  }
 }

mobile/lib/presentation/actions/favorite.action.dart

@@ -17,11 +17,9 @@ class FavoriteAction extends AssetAction<RemoteAsset> {
   String label(ActionScope scope) => shouldFavorite ? scope.context.t.favorite : scope.context.t.unfavorite;
 
   @override
-  Iterable<RemoteAsset> filter(ActionScope scope) => assets
-      .where(
-        (asset) => asset is RemoteAsset && asset.ownerId == scope.authUser.id && asset.isFavorite == !shouldFavorite,
-      )
-      .cast<RemoteAsset>();
+  Iterable<RemoteAsset> filter(ActionScope scope) => assets.whereType<RemoteAsset>().where(
+    (asset) => asset.ownerId == scope.authUser.id && asset.isFavorite == !shouldFavorite,
+  );
 
   @override
   bool isVisible(ActionScope scope) => filter(scope).isNotEmpty;

mobile/lib/presentation/actions/stack.action.dart

@@ -0,0 +1,44 @@
+import 'package:flutter/material.dart';
+import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
+import 'package:immich_mobile/generated/translations.g.dart';
+import 'package:immich_mobile/presentation/actions/action.dart';
+import 'package:immich_mobile/providers/infrastructure/asset.provider.dart';
+import 'package:immich_ui/immich_ui.dart';
+
+class StackAction extends AssetAction<RemoteAsset> {
+  final bool shouldStack;
+
+  StackAction({required super.assets})
+    : shouldStack = assets.any((asset) => asset is RemoteAsset && asset.stackId == null);
+
+  @override
+  IconData get icon => shouldStack ? Icons.filter_none_rounded : Icons.layers_clear_outlined;
+
+  @override
+  String label(ActionScope scope) => shouldStack ? scope.context.t.stack : scope.context.t.unstack;
+
+  @override
+  Iterable<RemoteAsset> filter(ActionScope scope) =>
+      assets.whereType<RemoteAsset>().where((asset) => asset.ownerId == scope.authUser.id);
+
+  @override
+  bool isVisible(ActionScope scope) => shouldStack ? filter(scope).length > 1 : filter(scope).isNotEmpty;
+
+  @override
+  Future<void> onAction(ActionScope scope) async {
+    final ActionScope(:ref) = scope;
+    final assets = filter(scope).toList(growable: false);
+    final service = ref.read(assetServiceProvider);
+
+    if (shouldStack) {
+      await service.stack(scope.authUser.id, assets.map((asset) => asset.id).toList(growable: false));
+    } else {
+      await service.unStack(assets.map((asset) => asset.stackId).nonNulls.toList(growable: false));
+    }
+
+    final message = shouldStack
+        ? StaticTranslations.instance.stacked_assets_count(count: assets.length)
+        : StaticTranslations.instance.unstacked_assets_count(count: assets.length);
+    snackbar.success(message);
+  }
+}

mobile/lib/presentation/widgets/action_buttons/stack_action_button.widget.dart

@@ -1,50 +0,0 @@
-import 'package:flutter/material.dart';
-import 'package:fluttertoast/fluttertoast.dart';
-import 'package:hooks_riverpod/hooks_riverpod.dart';
-import 'package:immich_mobile/constants/enums.dart';
-import 'package:immich_mobile/extensions/translate_extensions.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/base_action_button.widget.dart';
-import 'package:immich_mobile/providers/infrastructure/action.provider.dart';
-import 'package:immich_mobile/providers/timeline/multiselect.provider.dart';
-import 'package:immich_mobile/providers/user.provider.dart';
-import 'package:immich_mobile/widgets/common/immich_toast.dart';
-
-class StackActionButton extends ConsumerWidget {
-  final ActionSource source;
-
-  const StackActionButton({super.key, required this.source});
-
-  void _onTap(BuildContext context, WidgetRef ref) async {
-    if (!context.mounted) {
-      return;
-    }
-
-    final user = ref.watch(currentUserProvider);
-    if (user == null) {
-      throw Exception('User must be logged in to access stack action');
-    }
-
-    final result = await ref.read(actionProvider.notifier).stack(user.id, source);
-    ref.read(multiSelectProvider.notifier).reset();
-
-    final successMessage = 'stack_action_prompt'.t(context: context, args: {'count': result.count.toString()});
-
-    if (context.mounted) {
-      ImmichToast.show(
-        context: context,
-        msg: result.success ? successMessage : 'scaffold_body_error_occurred'.t(context: context),
-        gravity: ToastGravity.BOTTOM,
-        toastType: result.success ? ToastType.success : ToastType.error,
-      );
-    }
-  }
-
-  @override
-  Widget build(BuildContext context, WidgetRef ref) {
-    return BaseActionButton(
-      iconData: Icons.filter_none_rounded,
-      label: "stack".t(context: context),
-      onPressed: () => _onTap(context, ref),
-    );
-  }
-}

mobile/lib/presentation/widgets/action_buttons/unstack_action_button.widget.dart

@@ -1,48 +0,0 @@
-import 'package:flutter/material.dart';
-import 'package:fluttertoast/fluttertoast.dart';
-import 'package:hooks_riverpod/hooks_riverpod.dart';
-import 'package:immich_mobile/constants/enums.dart';
-import 'package:immich_mobile/extensions/translate_extensions.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/base_action_button.widget.dart';
-import 'package:immich_mobile/providers/infrastructure/action.provider.dart';
-import 'package:immich_mobile/providers/timeline/multiselect.provider.dart';
-import 'package:immich_mobile/widgets/common/immich_toast.dart';
-
-class UnStackActionButton extends ConsumerWidget {
-  final ActionSource source;
-  final bool iconOnly;
-  final bool menuItem;
-
-  const UnStackActionButton({super.key, required this.source, this.iconOnly = false, this.menuItem = false});
-
-  void _onTap(BuildContext context, WidgetRef ref) async {
-    if (!context.mounted) {
-      return;
-    }
-
-    final result = await ref.read(actionProvider.notifier).unStack(source);
-    ref.read(multiSelectProvider.notifier).reset();
-
-    final successMessage = 'unstack_action_prompt'.t(context: context, args: {'count': result.count.toString()});
-
-    if (context.mounted) {
-      ImmichToast.show(
-        context: context,
-        msg: result.success ? successMessage : 'scaffold_body_error_occurred'.t(context: context),
-        gravity: ToastGravity.BOTTOM,
-        toastType: result.success ? ToastType.success : ToastType.error,
-      );
-    }
-  }
-
-  @override
-  Widget build(BuildContext context, WidgetRef ref) {
-    return BaseActionButton(
-      iconData: Icons.layers_clear_outlined,
-      label: "unstack".t(context: context),
-      iconOnly: iconOnly,
-      menuItem: menuItem,
-      onPressed: () => _onTap(context, ref),
-    );
-  }
-}

mobile/lib/presentation/widgets/bottom_sheet/archive_bottom_sheet.widget.dart

@@ -5,6 +5,7 @@ import 'package:immich_mobile/constants/enums.dart';
 import 'package:immich_mobile/domain/models/album/album.model.dart';
 import 'package:immich_mobile/presentation/actions/action.widget.dart';
 import 'package:immich_mobile/presentation/actions/favorite.action.dart';
+import 'package:immich_mobile/presentation/actions/stack.action.dart';
 import 'package:immich_mobile/presentation/actions/timeline.action.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/delete_local_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/delete_permanent_action_button.widget.dart';
@@ -14,10 +15,8 @@ import 'package:immich_mobile/presentation/widgets/action_buttons/edit_location_
 import 'package:immich_mobile/presentation/widgets/action_buttons/move_to_lock_folder_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_link_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/stack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/trash_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/unarchive_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/unstack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/album/album_selector.widget.dart';
 import 'package:immich_mobile/presentation/widgets/bottom_sheet/base_bottom_sheet.widget.dart';
 import 'package:immich_mobile/providers/infrastructure/action.provider.dart';
@@ -77,7 +76,7 @@ class _ArchiveBottomSheetState extends ConsumerState<ArchiveBottomSheet> {
     }
 
     final assets = multiselect.selectedAssets.toList(growable: false);
-    final actions = [FavoriteAction(assets: assets)];
+    final actions = [FavoriteAction(assets: assets), StackAction(assets: assets)];
 
     return BaseBottomSheet(
       controller: sheetController,
@@ -97,8 +96,6 @@ class _ArchiveBottomSheetState extends ConsumerState<ArchiveBottomSheet> {
           const EditDateTimeActionButton(source: ActionSource.timeline),
           const EditLocationActionButton(source: ActionSource.timeline),
           const MoveToLockFolderActionButton(source: ActionSource.timeline),
-          if (multiselect.selectedAssets.length > 1) const StackActionButton(source: ActionSource.timeline),
-          if (multiselect.hasStacked) const UnStackActionButton(source: ActionSource.timeline),
         ],
         if (multiselect.hasMerged) const DeleteLocalActionButton(source: ActionSource.timeline),
       ],

mobile/lib/presentation/widgets/bottom_sheet/favorite_bottom_sheet.widget.dart

@@ -6,6 +6,7 @@ import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/extensions/translate_extensions.dart';
 import 'package:immich_mobile/presentation/actions/action.widget.dart';
 import 'package:immich_mobile/presentation/actions/favorite.action.dart';
+import 'package:immich_mobile/presentation/actions/stack.action.dart';
 import 'package:immich_mobile/presentation/actions/timeline.action.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/archive_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/delete_local_action_button.widget.dart';
@@ -16,9 +17,7 @@ import 'package:immich_mobile/presentation/widgets/action_buttons/edit_location_
 import 'package:immich_mobile/presentation/widgets/action_buttons/move_to_lock_folder_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_link_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/stack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/trash_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/unstack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/album/album_selector.widget.dart';
 import 'package:immich_mobile/presentation/widgets/bottom_sheet/base_bottom_sheet.widget.dart';
 import 'package:immich_mobile/providers/infrastructure/album.provider.dart';
@@ -68,7 +67,7 @@ class FavoriteBottomSheet extends ConsumerWidget {
     }
 
     final assets = multiselect.selectedAssets.toList(growable: false);
-    final actions = [FavoriteAction(assets: assets)];
+    final actions = [FavoriteAction(assets: assets), StackAction(assets: assets)];
 
     return BaseBottomSheet(
       initialChildSize: 0.4,
@@ -87,8 +86,6 @@ class FavoriteBottomSheet extends ConsumerWidget {
           const EditDateTimeActionButton(source: ActionSource.timeline),
           const EditLocationActionButton(source: ActionSource.timeline),
           const MoveToLockFolderActionButton(source: ActionSource.timeline),
-          if (multiselect.selectedAssets.length > 1) const StackActionButton(source: ActionSource.timeline),
-          if (multiselect.hasStacked) const UnStackActionButton(source: ActionSource.timeline),
         ],
         if (multiselect.hasMerged) const DeleteLocalActionButton(source: ActionSource.timeline),
       ],

mobile/lib/presentation/widgets/bottom_sheet/general_bottom_sheet.widget.dart

@@ -5,6 +5,7 @@ import 'package:immich_mobile/constants/enums.dart';
 import 'package:immich_mobile/domain/models/album/album.model.dart';
 import 'package:immich_mobile/presentation/actions/action.widget.dart';
 import 'package:immich_mobile/presentation/actions/asset_debug.action.dart';
+import 'package:immich_mobile/presentation/actions/stack.action.dart';
 import 'package:immich_mobile/presentation/actions/timeline.action.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/archive_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/bulk_tag_assets_action_button.widget.dart';
@@ -18,9 +19,7 @@ import 'package:immich_mobile/presentation/widgets/action_buttons/favorite_actio
 import 'package:immich_mobile/presentation/widgets/action_buttons/move_to_lock_folder_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_link_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/stack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/trash_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/unstack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/upload_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/album/album_selector.widget.dart';
 import 'package:immich_mobile/presentation/widgets/bottom_sheet/base_bottom_sheet.widget.dart';
@@ -84,7 +83,7 @@ class _GeneralBottomSheetState extends ConsumerState<GeneralBottomSheet> {
     }
 
     final assets = multiselect.selectedAssets.toList(growable: false);
-    final actions = [AssetDebugAction(assets: assets)];
+    final actions = [AssetDebugAction(assets: assets), StackAction(assets: assets)];
 
     return BaseBottomSheet(
       controller: sheetController,
@@ -107,8 +106,6 @@ class _GeneralBottomSheetState extends ConsumerState<GeneralBottomSheet> {
           const EditDateTimeActionButton(source: ActionSource.timeline),
           const EditLocationActionButton(source: ActionSource.timeline),
           const MoveToLockFolderActionButton(source: ActionSource.timeline),
-          if (multiselect.selectedAssets.length > 1) const StackActionButton(source: ActionSource.timeline),
-          if (multiselect.hasStacked) const UnStackActionButton(source: ActionSource.timeline),
           if (multiselect.onlyLocal || multiselect.hasMerged) const DeleteActionButton(source: ActionSource.timeline),
         ],
         if (multiselect.onlyLocal || multiselect.hasMerged)

mobile/lib/presentation/widgets/bottom_sheet/remote_album_bottom_sheet.widget.dart

@@ -5,6 +5,7 @@ import 'package:immich_mobile/domain/models/album/album.model.dart';
 import 'package:immich_mobile/extensions/translate_extensions.dart';
 import 'package:immich_mobile/presentation/actions/action.widget.dart';
 import 'package:immich_mobile/presentation/actions/favorite.action.dart';
+import 'package:immich_mobile/presentation/actions/stack.action.dart';
 import 'package:immich_mobile/presentation/actions/timeline.action.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/archive_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/delete_local_action_button.widget.dart';
@@ -17,9 +18,7 @@ import 'package:immich_mobile/presentation/widgets/action_buttons/remove_from_al
 import 'package:immich_mobile/presentation/widgets/action_buttons/set_album_cover.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_link_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/stack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/trash_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/unstack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/album/album_selector.widget.dart';
 import 'package:immich_mobile/presentation/widgets/bottom_sheet/base_bottom_sheet.widget.dart';
 import 'package:immich_mobile/providers/infrastructure/action.provider.dart';
@@ -86,7 +85,7 @@ class _RemoteAlbumBottomSheetState extends ConsumerState<RemoteAlbumBottomSheet>
     }
 
     final assets = multiselect.selectedAssets.toList(growable: false);
-    final actions = [FavoriteAction(assets: assets)];
+    final actions = [FavoriteAction(assets: assets), StackAction(assets: assets)];
 
     return BaseBottomSheet(
       controller: sheetController,
@@ -111,8 +110,6 @@ class _RemoteAlbumBottomSheetState extends ConsumerState<RemoteAlbumBottomSheet>
             const EditDateTimeActionButton(source: ActionSource.timeline),
             const EditLocationActionButton(source: ActionSource.timeline),
             const MoveToLockFolderActionButton(source: ActionSource.timeline),
-            if (multiselect.selectedAssets.length > 1) const StackActionButton(source: ActionSource.timeline),
-            if (multiselect.hasStacked) const UnStackActionButton(source: ActionSource.timeline),
           ],
         ],
         if (multiselect.hasMerged) const DeleteLocalActionButton(source: ActionSource.timeline),

mobile/lib/providers/timeline/multiselect.provider.dart

@@ -22,8 +22,6 @@ class MultiSelectState {
   bool get hasRemote =>
       selectedAssets.any((asset) => asset.storage == AssetState.remote || asset.storage == AssetState.merged);
 
-  bool get hasStacked => selectedAssets.any((asset) => asset is RemoteAsset && asset.stackId != null);
-
   bool get hasMerged => selectedAssets.any((asset) => asset.storage == AssetState.merged);
 
   bool get onlyLocal => selectedAssets.any((asset) => asset.storage == AssetState.local);

mobile/lib/utils/action_button.utils.dart

@@ -9,6 +9,7 @@ import 'package:immich_mobile/domain/services/timeline.service.dart';
 import 'package:immich_mobile/domain/utils/event_stream.dart';
 import 'package:immich_mobile/presentation/actions/action.widget.dart';
 import 'package:immich_mobile/presentation/actions/asset_debug.action.dart';
+import 'package:immich_mobile/presentation/actions/stack.action.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/archive_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/base_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/cast_action_button.widget.dart';
@@ -30,7 +31,6 @@ import 'package:immich_mobile/presentation/widgets/action_buttons/similar_photos
 import 'package:immich_mobile/presentation/widgets/action_buttons/slideshow_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/trash_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/unarchive_action_button.widget.dart';
-import 'package:immich_mobile/presentation/widgets/action_buttons/unstack_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/upload_action_button.widget.dart';
 import 'package:immich_mobile/routing/router.dart';
 
@@ -248,7 +248,7 @@ enum ActionButtonType {
         menuItem: menuItem,
       ),
       ActionButtonType.likeActivity => LikeActivityActionButton(iconOnly: iconOnly, menuItem: menuItem),
-      ActionButtonType.unstack => UnStackActionButton(source: context.source, iconOnly: iconOnly, menuItem: menuItem),
+      ActionButtonType.unstack => ActionMenuItemWidget(action: StackAction(assets: [context.asset])),
       ActionButtonType.openInBrowser => OpenInBrowserActionButton(
         remoteId: context.asset.remoteId!,
         origin: context.timelineOrigin,

mobile/test/unit/factories/remote_asset_factory.dart

@@ -5,7 +5,7 @@ import '../../utils.dart';
 class RemoteAssetFactory {
   const RemoteAssetFactory();
 
-  static RemoteAsset create({String? id, String? name, String? ownerId, bool isFavorite = false}) {
+  static RemoteAsset create({String? id, String? name, String? ownerId, bool isFavorite = false, String? stackId}) {
     id = TestUtils.uuid(id);
 
     return RemoteAsset(
@@ -17,6 +17,7 @@ class RemoteAssetFactory {
       createdAt: TestUtils.yesterday(),
       updatedAt: TestUtils.now(),
       isFavorite: isFavorite,
+      stackId: stackId,
       isEdited: false,
     );
   }

mobile/test/unit/mocks.dart

@@ -89,6 +89,8 @@ class ServiceMocks {
 
   void _stubAssetService() {
     when(asset.updateFavorite).thenAnswer((_) async {});
+    when(asset.stack).thenAnswer((_) async {});
+    when(asset.unStack).thenAnswer((_) async {});
   }
 }
 
@@ -167,6 +169,12 @@ extension type const UserServiceStub(MockUserService service) implements Stub<Mo
 extension type const AssetServiceStub(MockAssetService service) implements Stub<MockAssetService> {
   Future<void> Function() get updateFavorite =>
       () => service.updateFavorite(any(), any());
+
+  Future<void> Function() get stack =>
+      () => service.stack(any(), any());
+
+  Future<void> Function() get unStack =>
+      () => service.unStack(any());
 }
 
 extension type const NativeSyncApiStub(MockNativeSyncApi api) implements Stub<MockNativeSyncApi> {

mobile/test/unit/presentation/actions/stack_action_test.dart

@@ -0,0 +1,79 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
+import 'package:immich_mobile/presentation/actions/stack.action.dart';
+import 'package:mocktail/mocktail.dart';
+
+import '../../../domain/service.mock.dart';
+import '../../factories/remote_asset_factory.dart';
+import '../presentation_context.dart';
+
+void main() {
+  late PresentationContext context;
+  late MockAssetService assetService;
+
+  setUp(() async {
+    context = await PresentationContext.create();
+    assetService = context.service.asset.service;
+  });
+
+  tearDown(() {
+    context.dispose();
+  });
+
+  RemoteAsset owned({String? stackId}) => RemoteAssetFactory.create(ownerId: context.currentUser.id, stackId: stackId);
+
+  group('StackAction', () {
+    testWidgets('stacks the eligible owned assets', (tester) async {
+      final first = owned();
+      final second = owned();
+
+      await tester.pumpTestAction(context, StackAction(assets: [first, second]));
+
+      verify(() => assetService.stack(context.currentUser.id, [first.id, second.id])).called(1);
+    });
+
+    testWidgets('unstacks the eligible owned assets', (tester) async {
+      final asset = owned(stackId: 'stack');
+
+      await tester.pumpTestAction(context, StackAction(assets: [asset]));
+
+      verify(() => assetService.unStack(['stack'])).called(1);
+    });
+
+    testWidgets('prioritizes stack when mixed state', (tester) async {
+      final first = owned();
+      final second = owned(stackId: 'stack');
+
+      await tester.pumpTestAction(context, StackAction(assets: [first, second]));
+
+      verify(() => assetService.stack(context.currentUser.id, [first.id, second.id])).called(1);
+    });
+
+    testWidgets('ignores assets owned by someone else', (tester) async {
+      final mine = owned();
+      final other = owned();
+      final theirs = RemoteAssetFactory.create();
+
+      await tester.pumpTestAction(context, StackAction(assets: [mine, other, theirs]));
+
+      verify(() => assetService.stack(context.currentUser.id, [mine.id, other.id])).called(1);
+    });
+
+    testWidgets('unstacks every selected stack in a single call', (tester) async {
+      final first = owned(stackId: 'stack-1');
+      final second = owned(stackId: 'stack-2');
+
+      await tester.pumpTestAction(context, StackAction(assets: [first, second]));
+
+      verify(() => assetService.unStack(['stack-1', 'stack-2'])).called(1);
+    });
+
+    testWidgets('shows a confirmation snackbar on success', (tester) async {
+      await tester.pumpTestAction(context, StackAction(assets: [owned(), owned()]));
+      await tester.pumpUntilFound(find.byType(SnackBar));
+
+      expect(find.byType(SnackBar), findsOneWidget);
+    });
+  });
+}