Add fallback attributes to notifications for new and infrequent notifications (#38832)

app/controllers/api/v1/notifications_controller.rb

@@ -16,7 +16,7 @@ class Api::V1::NotificationsController < Api::BaseController
       @relationships = StatusRelationshipsPresenter.new(target_statuses_from_notifications, current_user&.account_id)
     end
 
-    render json: @notifications, each_serializer: REST::NotificationSerializer, relationships: @relationships
+    render json: @notifications, each_serializer: REST::NotificationSerializer, relationships: @relationships, supported_notification_types: params[:supported_types]
   end
 
   def unread_count
@@ -29,7 +29,7 @@ class Api::V1::NotificationsController < Api::BaseController
 
   def show
     @notification = current_account.notifications.without_suspended.find(params[:id])
-    render json: @notification, serializer: REST::NotificationSerializer
+    render json: @notification, serializer: REST::NotificationSerializer, supported_notification_types: params[:supported_types]
   end
 
   def clear
@@ -89,6 +89,8 @@ class Api::V1::NotificationsController < Api::BaseController
   end
 
   def pagination_params(core_params)
-    params.slice(:limit, :account_id, :types, :exclude_types, :include_filtered).permit(:limit, :account_id, :include_filtered, types: [], exclude_types: []).merge(core_params)
+    params.slice(:limit, :account_id, :types, :exclude_types, :include_filtered, :supported_types)
+      .permit(:limit, :account_id, :include_filtered, types: [], exclude_types: [], supported_types: [])
+      .merge(core_params)
   end
 end

app/controllers/api/v2/notifications_controller.rb

@@ -33,7 +33,7 @@ class Api::V2::NotificationsController < Api::BaseController
         'app.notification_grouping.expand_accounts_param' => expand_accounts_param
       )
 
-      render json: @presenter, serializer: REST::DedupNotificationGroupSerializer, relationships: @relationships, expand_accounts: expand_accounts_param
+      render json: @presenter, serializer: REST::DedupNotificationGroupSerializer, relationships: @relationships, expand_accounts: expand_accounts_param, supported_notification_types: params[:supported_types]
     end
   end
 
@@ -48,7 +48,7 @@ class Api::V2::NotificationsController < Api::BaseController
   def show
     @notification = current_account.notifications.without_suspended.by_group_key(params[:group_key]).take!
     presenter = GroupedNotificationsPresenter.new(NotificationGroup.from_notifications([@notification]))
-    render json: presenter, serializer: REST::DedupNotificationGroupSerializer
+    render json: presenter, serializer: REST::DedupNotificationGroupSerializer, supported_notification_types: params[:supported_types]
   end
 
   def clear
@@ -138,7 +138,9 @@ class Api::V2::NotificationsController < Api::BaseController
   end
 
   def pagination_params(core_params)
-    params.slice(:limit, :include_filtered, :types, :exclude_types, :grouped_types).permit(:limit, :include_filtered, types: [], exclude_types: [], grouped_types: []).merge(core_params)
+    params.slice(:limit, :include_filtered, :types, :exclude_types, :grouped_types, :supported_types)
+      .permit(:limit, :include_filtered, types: [], exclude_types: [], grouped_types: [], supported_types: [])
+      .merge(core_params)
   end
 
   def expand_accounts_param

app/lib/text_formatter.rb

@@ -76,6 +76,15 @@ class TextFormatter
     rescue Addressable::URI::InvalidURIError, IDN::Idna::IdnaError
       h(url)
     end
+
+    def link_to_mention(account, with_domain: false)
+      url = ActivityPub::TagManager.instance.url_for(account)
+      display_username = with_domain ? account.pretty_acct : account.username
+
+      <<~HTML.squish
+        <span class="h-card" translate="no"><a href="#{h(url)}" class="u-url mention">@<span>#{h(display_username)}</span></a></span>
+      HTML
+    end
   end
 
   private
@@ -136,12 +145,7 @@ class TextFormatter
 
     return "@#{h(entity[:screen_name])}" if account.nil?
 
-    url = ActivityPub::TagManager.instance.url_for(account)
+    TextFormatter.link_to_mention(account, with_domain: same_username_hits&.positive? || with_domains?)
-    display_username = same_username_hits&.positive? || with_domains? ? account.pretty_acct : account.username
-
-    <<~HTML.squish
-      <span class="h-card" translate="no"><a href="#{h(url)}" class="u-url mention">@<span>#{h(display_username)}</span></a></span>
-    HTML
   end
 
   def entity_cache

app/models/notification.rb

@@ -37,54 +37,71 @@ class Notification < ApplicationRecord
   PROPERTIES = {
     mention: {
       filterable: true,
+      baseline: true,
     }.freeze,
     status: {
       filterable: false,
+      baseline: true,
     }.freeze,
     reblog: {
       filterable: true,
+      baseline: true,
     }.freeze,
     follow: {
       filterable: true,
+      baseline: true,
     }.freeze,
     follow_request: {
       filterable: true,
+      baseline: true,
     }.freeze,
     favourite: {
       filterable: true,
+      baseline: true,
     }.freeze,
     poll: {
       filterable: false,
+      baseline: true,
     }.freeze,
     update: {
       filterable: false,
+      baseline: true,
     }.freeze,
     severed_relationships: {
       filterable: false,
+      baseline: false,
     }.freeze,
     moderation_warning: {
       filterable: false,
+      baseline: false,
     }.freeze,
     annual_report: {
       filterable: false,
+      baseline: true,
     }.freeze,
     'admin.sign_up': {
       filterable: false,
+      baseline: false,
     }.freeze,
     'admin.report': {
       filterable: false,
+      baseline: false,
     }.freeze,
     quote: {
       filterable: true,
+      baseline: true,
     }.freeze,
     quoted_update: {
       filterable: false,
+      baseline: true,
     }.freeze,
     added_to_collection: {
       filterable: true,
+      baseline: false,
     }.freeze,
     collection_update: {
       filterable: false,
+      baseline: false,
     }.freeze,
   }.freeze
 

app/serializers/concerns/notification_fallback_concern.rb

@@ -0,0 +1,96 @@
+# frozen_string_literal: true
+
+module NotificationFallbackConcern
+  extend ActiveSupport::Concern
+
+  def fallback
+    {
+      title: fallback_title,
+      summary: fallback_summary,
+      description: nil,
+    }
+  end
+
+  def needs_fallback?
+    return false if instance_options[:supported_notification_types].nil?
+    return false if Notification::PROPERTIES.dig(object.type, :baseline) || instance_options[:supported_notification_types].include?(object.type.to_s)
+
+    # In rare cases, a notification might be missing its activity, in which case we can't do much
+    case object.type
+    when :severed_relationships
+      object.account_relationship_severance_event.present?
+    when :'admin.report'
+      object.report.present?
+    when :added_to_collection, :collection_update
+      object.target_collection.present?
+    else
+      true
+    end
+  end
+
+  def fallback_title
+    account = object.is_a?(NotificationGroup) ? object.sample_accounts.first : object.from_account
+
+    case object.type
+    when :severed_relationships
+      I18n.t(
+        'notification_fallbacks.severed_relationships.title',
+        name: object.account_relationship_severance_event.target_name
+      )
+    when :moderation_warning
+      I18n.t('notification_fallbacks.moderation_warning.title')
+    when :'admin.sign_up'
+      count = object.is_a?(NotificationGroup) ? object.sample_accounts.count : 1
+      if count > 1
+        I18n.t(
+          'notification_fallbacks.admin_sign_up.title_and_others_html',
+          name: TextFormatter.link_to_mention(account),
+          count: count - 1
+        )
+      else
+        I18n.t(
+          'notification_fallbacks.admin_sign_up.title_html',
+          name: TextFormatter.link_to_mention(account)
+        )
+      end
+    when :'admin.report'
+      I18n.t(
+        'notification_fallbacks.admin_report.title_html',
+        name: account.remote? ? account.domain : TextFormatter.link_to_mention(account),
+        target: TextFormatter.link_to_mention(object.report.target_account)
+      )
+    when :added_to_collection
+      I18n.t(
+        'notification_fallbacks.added_to_collection.title_html',
+        name: TextFormatter.link_to_mention(account)
+      )
+    when :collection_update
+      I18n.t(
+        'notification_fallbacks.collection_update.title_html',
+        name: account
+      )
+    end
+  end
+
+  def fallback_summary
+    case object.type
+    when :severed_relationships
+      I18n.t(
+        'notification_fallbacks.severed_relationships.summary_html',
+        from: Rails.configuration.x.local_domain,
+        target: object.account_relationship_severance_event.target_name,
+        link: link_to(I18n.t('notification_fallbacks.generic.sign_in'), severed_relationships_url)
+      )
+    when :moderation_warning
+      I18n.t(
+        'notification_fallbacks.moderation_warning.summary_html',
+        link: link_to(I18n.t('notification_fallbacks.generic.sign_in'), disputes_strike_url(object.account_warning.id))
+      )
+    when :'admin.sign_up', :'admin.report', :added_to_collection, :collection_update
+      I18n.t(
+        'notification_fallbacks.generic.summary_html',
+        link: link_to(I18n.t('notification_fallbacks.generic.sign_in'), root_url)
+      )
+    end
+  end
+end

app/serializers/rest/notification_group_serializer.rb

@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 class REST::NotificationGroupSerializer < ActiveModel::Serializer
+  include RoutingHelper
+  include ActionView::Helpers::UrlHelper
+  include NotificationFallbackConcern
+
   # 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
 
@@ -8,6 +12,8 @@ class REST::NotificationGroupSerializer < ActiveModel::Serializer
   attribute :page_max_id, if: :paginated?
   attribute :latest_page_notification_at, if: :paginated?
 
+  attribute :fallback, if: :needs_fallback?
+
   attribute :sample_account_ids
   attribute :status_id, if: :status_type?
   belongs_to :report, if: :report_type?, serializer: REST::ReportSerializer

app/serializers/rest/notification_serializer.rb

@@ -1,11 +1,17 @@
 # frozen_string_literal: true
 
 class REST::NotificationSerializer < ActiveModel::Serializer
+  include RoutingHelper
+  include ActionView::Helpers::UrlHelper
+  include NotificationFallbackConcern
+
   # 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?
 
+  attribute :fallback, if: :needs_fallback?
+
   belongs_to :from_account, key: :account, serializer: REST::AccountSerializer
   belongs_to :target_status, key: :status, if: :status_type?, serializer: REST::StatusSerializer
   belongs_to :report, if: :report_type?, serializer: REST::ReportSerializer

config/locales/en.yml

@@ -1731,6 +1731,27 @@ en:
     copy_account_note_text: 'This user moved from %{acct}, here were your previous notes about them:'
   navigation:
     toggle_menu: Toggle menu
+  notification_fallbacks:
+    added_to_collection:
+      title_html: "%{name} added you to a collection"
+    admin_report:
+      title_html: "%{name} reported %{target}"
+    admin_sign_up:
+      title_and_others_html:
+        one: "%{name} and one other signed up"
+        other: "%{name} and %{count} others signed up"
+      title_html: "%{name} signed up"
+    collection_update:
+      title_html: "%{name} updated a collection you are in"
+    generic:
+      sign_in: Sign in to the Mastodon web app
+      summary_html: You're on an app that does not support the most recent version of Mastodon. %link for full functionality.
+    moderation_warning:
+      summary_html: You're on an app that does not support the most recent version of Mastodon. %link
+      title: You have received a moderation warning.
+    severed_relationships:
+      summary_html: An admin from %{from} has suspended %{target}, which means you can no longer receive updates from them or interact with them. %{link} to retrieve a list of the lost relationships.
+      title: Lost connections with %{name}
   notification_mailer:
     admin:
       report:

spec/serializers/rest/notification_group_serializer_spec.rb

@@ -6,10 +6,16 @@ RSpec.describe REST::NotificationGroupSerializer do
   subject do
     serialized_record_json(
       notification_group,
-      described_class
+      described_class,
+      options: {
+        scope: current_user,
+        scope_name: :current_user,
+        supported_notification_types: [],
+      }
     )
   end
 
+  let(:current_user) { Fabricate(:user) }
   let(:notification_group) { NotificationGroup.new pagination_data: { latest_notification_at: 3.days.ago }, notification: Fabricate(:notification), sample_accounts: [] }
 
   context 'when latest_page_notification_at is populated' do
@@ -20,4 +26,28 @@ RSpec.describe REST::NotificationGroupSerializer do
         )
     end
   end
+
+  shared_examples 'with fallback notifications' do |type, fabricators|
+    let(:activities) { fabricators.map { |fabricator| Fabricate(fabricator) } }
+    let(:notifications) { activities.map { |activity| Fabricate(:notification, type:, activity:, account: current_user.account) } }
+    let(:notification_group) { NotificationGroup.new(notification: notifications.last, sample_accounts: notifications.map(&:from_account)) }
+
+    it 'renders correctly' do
+      expect(subject)
+        .to include(
+          'type' => type,
+          'fallback' => include(
+            'title' => anything,
+            'summary' => anything
+          )
+        )
+    end
+  end
+
+  it_behaves_like 'with fallback notifications', 'severed_relationships', [:account_relationship_severance_event]
+  it_behaves_like 'with fallback notifications', 'moderation_warning', [:account_warning]
+  it_behaves_like 'with fallback notifications', 'admin.report', [:report]
+  it_behaves_like 'with fallback notifications', 'admin.report', [:report, :report]
+  it_behaves_like 'with fallback notifications', 'added_to_collection', [:collection_item]
+  it_behaves_like 'with fallback notifications', 'collection_update', [:collection]
 end

spec/serializers/rest/notification_serializer_spec.rb

@@ -6,10 +6,16 @@ RSpec.describe REST::NotificationSerializer do
   subject do
     serialized_record_json(
       notification,
-      described_class
+      described_class,
+      options: {
+        scope: current_user,
+        scope_name: :current_user,
+        supported_notification_types: [],
+      }
     )
   end
 
+  let(:current_user) { Fabricate(:user) }
   let(:notification) { Fabricate :notification }
 
   context 'when created_at is populated' do
@@ -20,4 +26,25 @@ RSpec.describe REST::NotificationSerializer do
         )
     end
   end
+
+  shared_examples 'with fallback notifications' do |type, fabricator|
+    let(:notification) { Fabricate(:notification, type:, activity: Fabricate(fabricator), account: current_user.account) }
+
+    it 'renders correctly' do
+      expect(subject)
+        .to include(
+          'type' => type,
+          'fallback' => include(
+            'title' => anything,
+            'summary' => anything
+          )
+        )
+    end
+  end
+
+  it_behaves_like 'with fallback notifications', 'severed_relationships', :account_relationship_severance_event
+  it_behaves_like 'with fallback notifications', 'moderation_warning', :account_warning
+  it_behaves_like 'with fallback notifications', 'admin.report', :report
+  it_behaves_like 'with fallback notifications', 'added_to_collection', :collection_item
+  it_behaves_like 'with fallback notifications', 'collection_update', :collection
 end