activity_owner_id not found for a particular model on destroy

[yo-gen]

I have setup a following follower relationship just as mentioned in Michael Hartl's Rail Tutorial.
And I am using getstream to generate notifications whenever a user gets followed

class Relationship < ApplicationRecord
  belongs_to :follower, class_name: "User"
  belongs_to :followed, class_name: "User"
  validates :follower_id, presence: true
  validates :followed_id, presence: true

  default_scope { order(created_at: :desc) }

  include StreamRails::Activity
  as_activity

  def activity_actor
    self.follower
  end

  def activity_object
    self
  end

  def activity_verb
    "follow"
  end

  def activity_target
    self.followed
  end

  def activity_notify
    [StreamRails.feed_manager.get_notification_feed(self.followed.id)]
  end
end

class User < ApplicationRecord
  has_many :active_relationships,  class_name:  "Relationship",
                                   foreign_key: "follower_id",
                                   dependent:   :destroy
  has_many :passive_relationships, class_name:  "Relationship",
                                   foreign_key: "followed_id",
                                   dependent:   :destroy
  has_many :following, through: :active_relationships,  source: :followed
  has_many :followers, through: :passive_relationships, source: :follower
end

When I try to destroy a user, it destroys the associated relationships as well, because of dependent destroy.
But stream rails throws following error in destroying the notification activities for relationship

Something went wrong deleting an activity: undefined method `id' for nil:NilClass
NoMethodError: undefined method `id' for nil:NilClass
from /home/yogen/.rvm/gems/ruby-2.4.4@stormy-island/gems/stream_rails-2.5.2/lib/stream_rails/activity.rb:34:in `activity_owner_id'

It works for other dependent destroy associations, but only fails for this one.
Anyone know why?

[yo-gen]

I would still like to understand the problem and figure out a clean solution for this.

But for now I have fixed this with adding a before_destroy in the Relationship model and just calling activity_owner_id in it once as shown below:

class Relationship < ApplicationRecord
  belongs_to :follower, class_name: "User"
  belongs_to :followed, class_name: "User"
  validates :follower_id, presence: true
  validates :followed_id, presence: true

  before_destroy :initialize_getstream

  default_scope { order(created_at: :desc) }

  include StreamRails::Activity
  as_activity

  def activity_actor
    self.follower
  end

  def activity_object
    self
  end

  def activity_verb
    "follow"
  end

  def activity_target
    self.followed
  end

  def activity_notify
    [StreamRails.feed_manager.get_notification_feed(self.followed.id)]
  end

  # Hack to avoid getstream error on delete. Don't know why this works!!!
  def initialize_getstream
    self.activity_owner_id
  end

end

[ruggi]

Hi @yo-gen , this issue is on my backlog, will look into it as soon as possible and let you know.

[yo-gen]

That's great. Do tell me if I can help.