Resolve "Extract logic of who should receive notification into separate classes"

app/services/notification_recipient_service.rb

+#
+# Used by NotificationService to determine who should receive notification
+#
+class NotificationRecipientService
+  attr_reader :project
+  
+  def initialize(project)
+    @project = project
+  end
+
+  def build_recipients(target, current_user, action: nil, previous_assignee: nil, skip_current_user: true)
+    custom_action = build_custom_key(action, target)
+
+    recipients = target.participants(current_user)
+
+    unless NotificationSetting::EXCLUDED_WATCHER_EVENTS.include?(custom_action)
+      recipients = add_project_watchers(recipients)
+    end
+
+    recipients = add_custom_notifications(recipients, custom_action)
+    recipients = reject_mention_users(recipients)
+
+    # Re-assign is considered as a mention of the new assignee so we add the
+    # new assignee to the list of recipients after we rejected users with
+    # the "on mention" notification level
+    if [:reassign_merge_request, :reassign_issue].include?(custom_action)
+      recipients << previous_assignee if previous_assignee
+      recipients << target.assignee
+    end
+
+    recipients = reject_muted_users(recipients)
+    recipients = add_subscribed_users(recipients, target)
+
+    if [:new_issue, :new_merge_request].include?(custom_action)
+      recipients = add_labels_subscribers(recipients, target)
+    end
+
+    recipients = reject_unsubscribed_users(recipients, target)
+    recipients = reject_users_without_access(recipients, target)
+
+    recipients.delete(current_user) if skip_current_user
+
+    recipients.uniq
+  end
+
+  def build_relabeled_recipients(target, current_user, labels:)
+    recipients = add_labels_subscribers([], target, labels: labels)
+    recipients = reject_unsubscribed_users(recipients, target)
+    recipients = reject_users_without_access(recipients, target)
+    recipients.delete(current_user)
+    recipients.uniq
+  end
+
+  def build_new_note_recipients(note)
+    target = note.noteable
+
+    ability, subject = if note.for_personal_snippet?
+                         [:read_personal_snippet, note.noteable]
+                       else
+                         [:read_project, note.project]
+                       end
+
+    mentioned_users = note.mentioned_users.select { |user| user.can?(ability, subject) }
+
+    # Add all users participating in the thread (author, assignee, comment authors)
+    recipients =
+      if target.respond_to?(:participants)
+        target.participants(note.author)
+      else
+        mentioned_users
+      end
+
+    unless note.for_personal_snippet?
+      # Merge project watchers
+      recipients = add_project_watchers(recipients)
+
+      # Merge project with custom notification
+      recipients = add_custom_notifications(recipients, :new_note)
+    end
+
+    # Reject users with Mention notification level, except those mentioned in _this_ note.
+    recipients = reject_mention_users(recipients - mentioned_users)
+    recipients = recipients + mentioned_users
+
+    recipients = reject_muted_users(recipients)
+
+    recipients = add_subscribed_users(recipients, note.noteable)
+    recipients = reject_unsubscribed_users(recipients, note.noteable)
+    recipients = reject_users_without_access(recipients, note.noteable)
+
+    recipients.delete(note.author)
+    recipients.uniq
+  end
+
+  # Remove users with disabled notifications from array
+  # Also remove duplications and nil recipients
+  def reject_muted_users(users)
+    reject_users(users, :disabled)
+  end
+
+  protected
+
+  # Get project/group users with CUSTOM notification level
+  def add_custom_notifications(recipients, action)
+    user_ids = []
+
+    # Users with a notification setting on group or project
+    user_ids += user_ids_notifiable_on(project, :custom, action)
+    user_ids += user_ids_notifiable_on(project.group, :custom, action)
+
+    # Users with global level custom
+    user_ids_with_project_level_global = user_ids_notifiable_on(project, :global)
+    user_ids_with_group_level_global   = user_ids_notifiable_on(project.group, :global)
+
+    global_users_ids = user_ids_with_project_level_global.concat(user_ids_with_group_level_global)
+    user_ids += user_ids_with_global_level_custom(global_users_ids, action)
+
+    recipients.concat(User.find(user_ids))
+  end
+
+  def add_project_watchers(recipients)
+    recipients.concat(project_watchers).compact
+  end
+
+  # Get project users with WATCH notification level
+  def project_watchers
+    project_members_ids = user_ids_notifiable_on(project)
+
+    user_ids_with_project_global = user_ids_notifiable_on(project, :global)
+    user_ids_with_group_global   = user_ids_notifiable_on(project.group, :global)
+
+    user_ids = user_ids_with_global_level_watch((user_ids_with_project_global + user_ids_with_group_global).uniq)
+
+    user_ids_with_project_setting = select_project_members_ids(project, user_ids_with_project_global, user_ids)
+    user_ids_with_group_setting = select_group_members_ids(project.group, project_members_ids, user_ids_with_group_global, user_ids)
+
+    User.where(id: user_ids_with_project_setting.concat(user_ids_with_group_setting).uniq).to_a
+  end
+
+  # Remove users with notification level 'Mentioned'
+  def reject_mention_users(users)
+    reject_users(users, :mention)
+  end
+
+  def add_subscribed_users(recipients, target)
+    return recipients unless target.respond_to? :subscribers
+
+    recipients + target.subscribers(project)
+  end
+
+  def user_ids_notifiable_on(resource, notification_level = nil, action = nil)
+    return [] unless resource
+
+    if notification_level
+      settings = resource.notification_settings.where(level: NotificationSetting.levels[notification_level])
+      settings = settings.select { |setting| setting.events[action] } if action.present?
+      settings.map(&:user_id)
+    else
+      resource.notification_settings.pluck(:user_id)
+    end
+  end
+
+  # Build a list of user_ids based on project notification settings
+  def select_project_members_ids(project, global_setting, user_ids_global_level_watch)
+    user_ids = user_ids_notifiable_on(project, :watch)
+
+    # If project setting is global, add to watch list if global setting is watch
+    global_setting.each do |user_id|
+      if user_ids_global_level_watch.include?(user_id)
+        user_ids << user_id
+      end
+    end
+
+    user_ids
+  end
+
+  # Build a list of user_ids based on group notification settings
+  def select_group_members_ids(group, project_members, global_setting, user_ids_global_level_watch)
+    uids = user_ids_notifiable_on(group, :watch)
+
+    # Group setting is watch, add to user_ids list if user is not project member
+    user_ids = []
+    uids.each do |user_id|
+      if project_members.exclude?(user_id)
+        user_ids << user_id
+      end
+    end
+
+    # Group setting is global, add to user_ids list if global setting is watch
+    global_setting.each do |user_id|
+      if project_members.exclude?(user_id) && user_ids_global_level_watch.include?(user_id)
+        user_ids << user_id
+      end
+    end
+
+    user_ids
+  end
+
+  def user_ids_with_global_level_watch(ids)
+    settings_with_global_level_of(:watch, ids).pluck(:user_id)
+  end
+
+  def user_ids_with_global_level_custom(ids, action)
+    settings = settings_with_global_level_of(:custom, ids)
+    settings = settings.select { |setting| setting.events[action] }
+    settings.map(&:user_id)
+  end
+
+  def settings_with_global_level_of(level, ids)
+    NotificationSetting.where(
+      user_id: ids,
+      source_type: nil,
+      level: NotificationSetting.levels[level]
+    )
+  end
+
+  # Reject users which has certain notification level
+  #
+  # Example:
+  #   reject_users(users, :watch, project)
+  #
+  def reject_users(users, level)
+    level = level.to_s
+
+    unless NotificationSetting.levels.keys.include?(level)
+      raise 'Invalid notification level'
+    end
+
+    users = users.to_a.compact.uniq
+    users = users.select { |u| u.can?(:receive_notifications) }
+
+    users.reject do |user|
+      global_notification_setting = user.global_notification_setting
+
+      next global_notification_setting.level == level unless project
+
+      setting = user.notification_settings_for(project)
+
+      if project.group && (setting.nil? || setting.global?)
+        setting = user.notification_settings_for(project.group)
+      end
+
+      # reject users who globally set mention notification and has no setting per project/group
+      next global_notification_setting.level == level unless setting
+
+      # reject users who set mention notification in project
+      next true if setting.level == level
+
+      # reject users who have mention level in project and disabled in global settings
+      setting.global? && global_notification_setting.level == level
+    end
+  end
+
+  def reject_unsubscribed_users(recipients, target)
+    return recipients unless target.respond_to? :subscriptions
+
+    recipients.reject do |user|
+      subscription = target.subscriptions.find_by_user_id(user.id)
+      subscription && !subscription.subscribed
+    end
+  end
+
+  def reject_users_without_access(recipients, target)
+    ability = case target
+              when Issuable
+                :"read_#{target.to_ability_name}"
+              when Ci::Pipeline
+                :read_build # We have build trace in pipeline emails
+              end
+
+    return recipients unless ability
+
+    recipients.select do |user|
+      user.can?(ability, target)
+    end
+  end
+
+  def add_labels_subscribers(recipients, target, labels: nil)
+    return recipients unless target.respond_to? :labels
+
+    (labels || target.labels).each do |label|
+      recipients += label.subscribers(project)
+    end
+
+    recipients
+  end
+
+  # Build event key to search on custom notification level
+  # Check NotificationSetting::EMAIL_EVENTS
+  def build_custom_key(action, object)
+    "#{action}_#{object.class.model_name.name.underscore}".to_sym
+  end
+end

spec/services/notification_service_spec.rb

@@ -758,7 +758,7 @@ describe NotificationService, services: true do
         update_custom_notification(:reopen_issue, @u_custom_global)
       end
 
-      it 'sends email to issue assignee and issue author' do
+      it 'sends email to issue notification recipients' do
         notification.reopen_issue(issue, @u_disabled)
 
         should_email(issue.assignee)
@@ -772,6 +772,7 @@ describe NotificationService, services: true do
         should_email(@watcher_and_subscriber)
         should_not_email(@unsubscriber)
         should_not_email(@u_participating)
+        should_not_email(@u_disabled)
         should_not_email(@u_lazy_participant)
       end
 
@@ -781,6 +782,32 @@ describe NotificationService, services: true do
         let(:notification_trigger) { notification.reopen_issue(issue, @u_disabled) }
       end
     end
+
+    describe '#issue_moved' do
+      let(:new_issue) { create(:issue) }
+
+      it 'sends email to issue notification recipients' do
+        notification.issue_moved(issue, new_issue, @u_disabled)
+
+        should_email(issue.assignee)
+        should_email(issue.author)
+        should_email(@u_watcher)
+        should_email(@u_guest_watcher)
+        should_email(@u_participant_mentioned)
+        should_email(@subscriber)
+        should_email(@watcher_and_subscriber)
+        should_not_email(@unsubscriber)
+        should_not_email(@u_participating)
+        should_not_email(@u_disabled)
+        should_not_email(@u_lazy_participant)
+      end
+
+      it_behaves_like 'participating notifications' do
+        let(:participant) { create(:user, username: 'user-participant') }
+        let(:issuable) { issue }
+        let(:notification_trigger) { notification.issue_moved(issue, new_issue, @u_disabled) }
+      end
+    end
   end
 
   describe 'Merge Requests' do
@@ -1192,6 +1219,48 @@ describe NotificationService, services: true do
     end
   end
 
+  describe 'Pipelines' do
+    describe '#pipeline_finished' do
+      let(:project) { create(:project, :public) }
+      let(:current_user) { create(:user) }
+      let(:u_member) { create(:user) }
+      let(:u_other) { create(:user) }
+
+      let(:commit) { project.commit }
+      let(:pipeline) do
+        create(:ci_pipeline, :success,
+               project: project,
+               user: current_user,
+               ref: 'refs/heads/master',
+               sha: commit.id,
+               before_sha: '00000000')
+      end
+
+      before do
+        project.add_master(current_user)
+        project.add_master(u_member)
+        reset_delivered_emails!
+      end
+
+      context 'without custom recipients' do
+        it 'notifies the pipeline user' do
+          notification.pipeline_finished(pipeline)
+
+          should_only_email(current_user, kind: :bcc)
+        end
+      end
+
+      context 'with custom recipients' do
+        it 'notifies the custom recipients' do
+          users = [u_member, u_other]
+          notification.pipeline_finished(pipeline, users.map(&:notification_email))
+
+          should_only_email(*users, kind: :bcc)
+        end
+      end
+    end
+  end
+
   def build_team(project)
     @u_watcher               = create_global_setting_for(create(:user), :watch)
     @u_participating         = create_global_setting_for(create(:user), :participating)