Add added_to_collection and collection_updated notification types (#38491)

app/javascript/mastodon/api_types/notifications.ts

@@ -3,6 +3,7 @@
 import type { AccountWarningAction } from 'mastodon/models/notification_group';
 
 import type { ApiAccountJSON } from './accounts';
+import type { ApiCollectionJSON } from './collections';
 import type { ApiReportJSON } from './reports';
 import type { ApiStatusJSON } from './statuses';
 
@@ -22,6 +23,8 @@ export const allNotificationTypes: NotificationType[] = [
   'moderation_warning',
   'severed_relationships',
   'annual_report',
+  'added_to_collection',
+  'collection_update',
 ];
 
 export type NotificationWithStatusType =
@@ -42,7 +45,9 @@ export type NotificationType =
   | 'severed_relationships'
   | 'admin.sign_up'
   | 'admin.report'
-  | 'annual_report';
+  | 'annual_report'
+  | 'added_to_collection'
+  | 'collection_update';
 
 export interface BaseNotificationJSON {
   id: string;
@@ -83,6 +88,26 @@ interface ReportNotificationJSON extends BaseNotificationJSON {
   report: ApiReportJSON;
 }
 
+interface AddedToCollectionNotificationGroupJSON extends BaseNotificationGroupJSON {
+  type: 'added_to_collection';
+  collection: ApiCollectionJSON;
+}
+
+interface AddedToCollectionNotificationJSON extends BaseNotificationJSON {
+  type: 'added_to_collection';
+  collection: ApiCollectionJSON;
+}
+
+interface CollectionUpdateNotificationGroupJSON extends BaseNotificationGroupJSON {
+  type: 'collection_update';
+  collection: ApiCollectionJSON;
+}
+
+interface CollectionUpdateNotificationJSON extends BaseNotificationJSON {
+  type: 'collection_update';
+  collection: ApiCollectionJSON;
+}
+
 type SimpleNotificationTypes = 'follow' | 'follow_request' | 'admin.sign_up';
 interface SimpleNotificationGroupJSON extends BaseNotificationGroupJSON {
   type: SimpleNotificationTypes;
@@ -146,7 +171,9 @@ export type ApiNotificationJSON =
   | ReportNotificationJSON
   | AccountRelationshipSeveranceNotificationJSON
   | NotificationWithStatusJSON
-  | ModerationWarningNotificationJSON;
+  | ModerationWarningNotificationJSON
+  | AddedToCollectionNotificationJSON
+  | CollectionUpdateNotificationJSON;
 
 export type ApiNotificationGroupJSON =
   | SimpleNotificationGroupJSON
@@ -154,7 +181,9 @@ export type ApiNotificationGroupJSON =
   | AccountRelationshipSeveranceNotificationGroupJSON
   | NotificationGroupWithStatusJSON
   | ModerationWarningNotificationGroupJSON
-  | AnnualReportNotificationGroupJSON;
+  | AnnualReportNotificationGroupJSON
+  | AddedToCollectionNotificationGroupJSON
+  | CollectionUpdateNotificationGroupJSON;
 
 export interface ApiNotificationGroupsResultJSON {
   accounts: ApiAccountJSON[];

app/javascript/mastodon/models/notification_group.ts

@@ -10,6 +10,8 @@ import type {
 } from 'mastodon/api_types/notifications';
 import type { ApiReportJSON } from 'mastodon/api_types/reports';
 
+import type { ApiCollectionJSON } from '../api_types/collections';
+
 // Maximum number of avatars displayed in a notification group
 // This corresponds to the max length of `group.sampleAccountIds`
 export const NOTIFICATIONS_GROUP_MAX_AVATARS = 8;
@@ -87,6 +89,15 @@ export interface NotificationGroupAdminReport extends BaseNotification<'admin.re
   report: Report;
 }
 
+type Collection = ApiCollectionJSON;
+export interface NotificationGroupAddedToCollection extends BaseNotification<'added_to_collection'> {
+  collection: Collection;
+}
+
+export interface NotificationGroupCollectionUpdate extends BaseNotification<'collection_update'> {
+  collection: Collection;
+}
+
 export type NotificationGroup =
   | NotificationGroupFavourite
   | NotificationGroupReblog
@@ -102,7 +113,9 @@ export type NotificationGroup =
   | NotificationGroupSeveredRelationships
   | NotificationGroupAdminSignUp
   | NotificationGroupAdminReport
-  | NotificationGroupAnnualReport;
+  | NotificationGroupAnnualReport
+  | NotificationGroupAddedToCollection
+  | NotificationGroupCollectionUpdate;
 
 function createReportFromJSON(reportJSON: ApiReportJSON): Report {
   const { target_account, ...report } = reportJSON;
@@ -249,6 +262,13 @@ export function createNotificationGroupFromNotificationJSON(
           notification.moderation_warning,
         ),
       };
+    case 'added_to_collection':
+    case 'collection_update':
+      return {
+        ...group,
+        type: notification.type,
+        collection: notification.collection,
+      };
     default:
       return {
         ...group,

app/lib/activitypub/activity/feature_request.rb

@@ -26,6 +26,7 @@ class ActivityPub::Activity::FeatureRequest < ActivityPub::Activity
       collection_item_attributes(:accepted)
     )
 
+    notify_local_user!(collection_item)
     queue_delivery!(collection_item, ActivityPub::AcceptFeatureRequestSerializer)
   end
 
@@ -52,6 +53,10 @@ class ActivityPub::Activity::FeatureRequest < ActivityPub::Activity
     { account: @featured_account, activity_uri: @json['id'], state: }
   end
 
+  def notify_local_user!(collection_item)
+    LocalNotificationWorker.perform_async(collection_item.account_id, collection_item.id, collection_item.class.name, 'added_to_collection')
+  end
+
   def queue_delivery!(collection_item, serializer)
     json = JSON.generate(serialize_payload(collection_item, serializer))
     ActivityPub::DeliveryWorker.perform_async(json, @featured_account.id, @account.inbox_url)

app/models/notification.rb

@@ -33,7 +33,7 @@ class Notification < ApplicationRecord
     'Quote' => :quote,
   }.freeze
 
-  # Please update app/javascript/api_types/notification.ts if you change this
+  # Please update app/javascript/mastodon/api_types/notifications.ts if you change this
   PROPERTIES = {
     mention: {
       filterable: true,
@@ -80,6 +80,12 @@ class Notification < ApplicationRecord
     quoted_update: {
       filterable: false,
     }.freeze,
+    added_to_collection: {
+      filterable: true,
+    }.freeze,
+    collection_update: {
+      filterable: false,
+    },
   }.freeze
 
   TYPES = PROPERTIES.keys.freeze
@@ -112,6 +118,8 @@ class Notification < ApplicationRecord
     belongs_to :account_warning, inverse_of: false
     belongs_to :generated_annual_report, inverse_of: false
     belongs_to :quote, inverse_of: :notification
+    belongs_to :collection_item, inverse_of: false # TODO: have an inverse?
+    belongs_to :collection, inverse_of: false # TODO: have an inverse?
   end
 
   validates :type, inclusion: { in: TYPES }
@@ -208,8 +216,10 @@ class Notification < ApplicationRecord
     case activity_type
     when 'Status'
       self.from_account_id = type == :quoted_update ? activity&.quote&.quoted_account_id : activity&.account_id
-    when 'Follow', 'Favourite', 'FollowRequest', 'Poll', 'Report', 'Quote'
+    when 'Follow', 'Favourite', 'FollowRequest', 'Poll', 'Report', 'Quote', 'Collection'
       self.from_account_id = activity&.account_id
+    when 'CollectionItem'
+      self.from_account_id = activity&.collection&.account_id
     when 'Mention'
       self.from_account_id = activity&.status&.account_id
     when 'Account'

app/serializers/rest/notification_group_serializer.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class REST::NotificationGroupSerializer < ActiveModel::Serializer
-  # Please update app/javascript/api_types/notification.ts when making changes to the attributes
+  # Please update app/javascript/mastodon/api_types/notifications.ts when making changes to the attributes
   attributes :group_key, :notifications_count, :type, :most_recent_notification_id
 
   attribute :page_min_id, if: :paginated?
@@ -14,6 +14,7 @@ class REST::NotificationGroupSerializer < ActiveModel::Serializer
   belongs_to :account_relationship_severance_event, key: :event, if: :relationship_severance_event?, serializer: REST::AccountRelationshipSeveranceEventSerializer
   belongs_to :account_warning, key: :moderation_warning, if: :moderation_warning_event?, serializer: REST::AccountWarningSerializer
   belongs_to :generated_annual_report, key: :annual_report, if: :annual_report_event?, serializer: REST::AnnualReportEventSerializer
+  belongs_to :collection, if: :collection_type?, serializer: REST::CollectionSerializer
 
   def sample_account_ids
     object.sample_accounts.pluck(:id).map(&:to_s)
@@ -27,6 +28,10 @@ class REST::NotificationGroupSerializer < ActiveModel::Serializer
     [:favourite, :reblog, :status, :mention, :poll, :update, :quote, :quoted_update].include?(object.type)
   end
 
+  def collection_type?
+    [:added_to_collection, :collection_update].include?(object.type)
+  end
+
   def report_type?
     object.type == :'admin.report'
   end

app/serializers/rest/notification_serializer.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class REST::NotificationSerializer < ActiveModel::Serializer
-  # Please update app/javascript/api_types/notification.ts when making changes to the attributes
+  # Please update app/javascript/mastodon/api_types/notifications.ts when making changes to the attributes
   attributes :id, :type, :created_at, :group_key
 
   attribute :filtered, if: :filtered?
@@ -11,6 +11,7 @@ class REST::NotificationSerializer < ActiveModel::Serializer
   belongs_to :report, if: :report_type?, serializer: REST::ReportSerializer
   belongs_to :account_relationship_severance_event, key: :event, if: :relationship_severance_event?, serializer: REST::AccountRelationshipSeveranceEventSerializer
   belongs_to :account_warning, key: :moderation_warning, if: :moderation_warning_event?, serializer: REST::AccountWarningSerializer
+  belongs_to :collection, if: :collection_type?, serializer: REST::CollectionSerializer
 
   def id
     object.id.to_s
@@ -24,6 +25,10 @@ class REST::NotificationSerializer < ActiveModel::Serializer
     [:favourite, :reblog, :status, :mention, :poll, :update, :quoted_update, :quote].include?(object.type)
   end
 
+  def collection_type?
+    [:added_to_collection, :collection_update].include?(object.type)
+  end
+
   def report_type?
     object.type == :'admin.report'
   end

app/services/activitypub/process_featured_collection_service.rb

@@ -25,6 +25,7 @@ class ActivityPub::ProcessFeaturedCollectionService
       end
 
       process_items!
+      notify_about_update!
 
       @collection
     end
@@ -32,6 +33,10 @@ class ActivityPub::ProcessFeaturedCollectionService
 
   private
 
+  def notify_about_update!
+    NotifyOfCollectionUpdateService.new.call(@collection)
+  end
+
   def truncated_summary
     text = @json['summaryMap']&.values&.first || @json['summary'] || ''
     text[0, Collection::DESCRIPTION_LENGTH_HARD_LIMIT]

app/services/add_account_to_collection_service.rb

@@ -11,6 +11,7 @@ class AddAccountToCollectionService
 
     @collection_item = create_collection_item
 
+    notify_local_user if @account.local?
     distribute_add_activity if @account.local?
     distribute_feature_request_activity if @account.remote?
 
@@ -24,6 +25,10 @@ class AddAccountToCollectionService
     @collection.collection_items.create!(account: @account, state:)
   end
 
+  def notify_local_user
+    LocalNotificationWorker.perform_async(@account.id, @collection_item.id, @collection_item.class.name, 'added_to_collection')
+  end
+
   def distribute_add_activity
     ActivityPub::AccountRawDistributionWorker.perform_async(add_activity_json, @collection.account_id)
   end

app/services/notify_of_collection_update_service.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class NotifyOfCollectionUpdateService
+  def call(collection)
+    return unless significantly_changed?(collection)
+
+    collection.collection_items.includes(:account).references(:account).merge(Account.local).accepted.find_each do |collection_item|
+      LocalNotificationWorker.perform_async(collection_item.account_id, collection.id, collection.class.name, 'collection_update')
+    end
+  end
+
+  private
+
+  def significantly_changed?(collection)
+    # If the collection is brand new, we don't need to look at its members
+    return false if collection.previously_new_record?
+
+    # Only notify of change to description or name
+    %i(description description_html name).any? { |attr| collection.attribute_previously_changed?(attr) }
+  end
+end

app/services/notify_service.rb

@@ -14,6 +14,8 @@ class NotifyService < BaseService
     moderation_warning
     severed_relationships
     annual_report
+    added_to_collection
+    collection_update
   ).freeze
 
   class BaseCondition
@@ -21,15 +23,6 @@ class NotifyService < BaseService
 
     NEW_FOLLOWER_THRESHOLD = 3.days.freeze
 
-    NON_FILTERABLE_TYPES = %i(
-      admin.sign_up
-      admin.report
-      poll
-      update
-      account_warning
-      annual_report
-    ).freeze
-
     def initialize(notification, **options)
       @recipient = notification.account
       @sender = notification.from_account

app/services/update_collection_service.rb

@@ -7,6 +7,7 @@ class UpdateCollectionService
     @collection = collection
     @collection.update!(params)
 
+    notify_about_update
     distribute_update_activity
   end
 
@@ -18,6 +19,10 @@ class UpdateCollectionService
     ActivityPub::AccountRawDistributionWorker.perform_async(activity_json, @collection.account.id)
   end
 
+  def notify_about_update
+    NotifyOfCollectionUpdateService.new.call(@collection)
+  end
+
   def activity_json
     ActiveModelSerializers::SerializableResource.new(@collection, serializer: ActivityPub::UpdateFeaturedCollectionSerializer, adapter: ActivityPub::Adapter).to_json
   end

app/workers/local_notification_worker.rb

@@ -10,10 +10,8 @@ class LocalNotificationWorker
     # For most notification types, only one notification should exist, and the older one is
     # preferred. For updates, such as when a status is edited, the new notification
     # should replace the previous ones.
-    if type == 'update'
-      Notification.where(account: receiver, activity: activity, type: 'update').in_batches.delete_all
-    elsif type == 'quoted_update'
-      Notification.where(account: receiver, activity: activity, type: 'quoted_update').in_batches.delete_all
+    if %w(update quoted_update collection_update).include?(type)
+      Notification.where(account: receiver, activity: activity, type: type).in_batches.delete_all
     elsif Notification.where(account: receiver, activity: activity, type: type).any?
       return
     end

spec/lib/activitypub/activity/feature_request_spec.rb

@@ -26,9 +26,10 @@ RSpec.describe ActivityPub::Activity::FeatureRequest do
     context 'when recipient is discoverable' do
       let(:discoverable) { true }
 
-      it 'schedules a job to send an `Accept` activity' do
+      it 'schedules a job to send an `Accept` activity as well as a notification worker' do
         expect { subject.perform }
-          .to enqueue_sidekiq_job(ActivityPub::DeliveryWorker)
+          .to enqueue_sidekiq_job(LocalNotificationWorker).with(recipient.id, anything, 'CollectionItem', 'added_to_collection')
+          .and enqueue_sidekiq_job(ActivityPub::DeliveryWorker)
           .with(satisfying do |body|
             response_json = JSON.parse(body)
             response_json['type'] == 'Accept' &&

spec/lib/activitypub/activity/update_spec.rb

@@ -259,6 +259,9 @@ RSpec.describe ActivityPub::Activity::Update do
 
     context 'with a `FeaturedCollection` object', feature: :collections do
       let(:collection) { Fabricate(:remote_collection, account: sender, name: 'old name', discoverable: false) }
+      let(:account) { Fabricate(:account) }
+      let!(:collection_item) { Fabricate(:collection_item, account:, collection:, uri: 'https://example.com/featured_stamps/1') }
+
       let(:featured_collection_json) do
         {
           '@context' => 'https://www.w3.org/ns/activitystreams',
@@ -267,13 +270,21 @@ RSpec.describe ActivityPub::Activity::Update do
           'attributedTo' => sender.uri,
           'name' => 'Cool people',
           'summary' => 'People you should follow.',
-          'totalItems' => 0,
+          'totalItems' => 1,
           'sensitive' => false,
           'discoverable' => true,
           'published' => '2026-03-09T15:19:25Z',
           'updated' => Time.zone.now.iso8601,
+          'orderedItems' => [
+            {
+              'type' => 'FeaturedItem',
+              'id' => ActivityPub::TagManager.instance.uri_for(collection_item),
+              'object' => ActivityPub::TagManager.instance.uri_for(account),
+            },
+          ],
         }
       end
+
       let(:json) do
         {
           '@context' => 'https://www.w3.org/ns/activitystreams',
@@ -282,18 +293,41 @@ RSpec.describe ActivityPub::Activity::Update do
           'object' => featured_collection_json,
         }
       end
-      let(:stubbed_service) do
-        instance_double(ActivityPub::ProcessFeaturedCollectionService, call: true)
+
+      it 'updates the collection and notifies local user' do
+        expect { subject.perform }
+          .to change { collection.reload.name }.to(featured_collection_json['name'])
+          .and enqueue_sidekiq_job(LocalNotificationWorker).with(account.id, collection.id, 'Collection', 'collection_update')
       end
 
-      before do
-        allow(ActivityPub::ProcessFeaturedCollectionService).to receive(:new).and_return(stubbed_service)
-      end
+      context 'when the metadata does not actually change' do
+        let(:featured_collection_json) do
+          {
+            '@context' => 'https://www.w3.org/ns/activitystreams',
+            'id' => collection.uri,
+            'type' => 'FeaturedCollection',
+            'attributedTo' => sender.uri,
+            'name' => collection.name,
+            'summary' => collection.description_html,
+            'totalItems' => 1,
+            'sensitive' => false,
+            'discoverable' => true,
+            'published' => '2026-03-09T15:19:25Z',
+            'updated' => Time.zone.now.iso8601,
+            'orderedItems' => [
+              {
+                'type' => 'FeaturedItem',
+                'id' => ActivityPub::TagManager.instance.uri_for(collection_item),
+                'object' => ActivityPub::TagManager.instance.uri_for(account),
+              },
+            ],
+          }
+        end
 
-      it 'updates the collection' do
-        subject.perform
-
-        expect(stubbed_service).to have_received(:call).with(sender, featured_collection_json)
+        it 'does not notify the local user' do
+          expect { subject.perform }
+            .to_not enqueue_sidekiq_job(LocalNotificationWorker)
+        end
       end
     end
   end

spec/services/add_account_to_collection_service_spec.rb

@@ -22,10 +22,15 @@ RSpec.describe AddAccountToCollectionService do
       end
 
       context 'when the account is local' do
-        it 'federates an `Add` activity' do
+        it 'federates an `Add` activity and schedules a notification' do
           subject.call(collection, account)
 
-          expect(ActivityPub::AccountRawDistributionWorker).to have_enqueued_sidekiq_job
+          expect(ActivityPub::AccountRawDistributionWorker)
+            .to have_enqueued_sidekiq_job
+            .with(anything, collection.account_id)
+          expect(LocalNotificationWorker)
+            .to have_enqueued_sidekiq_job
+            .with(account.id, anything, 'CollectionItem', 'added_to_collection')
         end
       end
 

spec/services/update_collection_service_spec.rb

@@ -6,21 +6,15 @@ RSpec.describe UpdateCollectionService do
   subject { described_class.new }
 
   let(:collection) { Fabricate(:collection) }
+  let!(:collection_item) { Fabricate(:collection_item, collection:) }
 
   describe '#call' do
     context 'when given valid parameters' do
-      it 'updates the collection' do
-        subject.call(collection, { name: 'Newly updated name' })
-
-        expect(collection.name).to eq 'Newly updated name'
-      end
-
-      context 'when something actually changed' do
-        it 'federates an `Update` activity' do
-          subject.call(collection, { name: 'updated' })
-
-          expect(ActivityPub::AccountRawDistributionWorker).to have_enqueued_sidekiq_job
-        end
+      it 'updates the collection, sends a notification and federates an `Update` activity' do
+        expect { subject.call(collection, { name: 'Newly updated name' }) }
+          .to change(collection, :name).to('Newly updated name')
+          .and enqueue_sidekiq_job(LocalNotificationWorker).with(collection_item.account_id, collection.id, collection.class.name, 'collection_update')
+          .and enqueue_sidekiq_job(ActivityPub::AccountRawDistributionWorker)
       end
 
       context 'when nothing changed' do
@@ -28,6 +22,7 @@ RSpec.describe UpdateCollectionService do
           subject.call(collection, { name: collection.name })
 
           expect(ActivityPub::AccountRawDistributionWorker).to_not have_enqueued_sidekiq_job
+          expect(LocalNotificationWorker).to_not have_enqueued_sidekiq_job
         end
       end
     end