Hacky fix for rails 5.0.0-5.0.6 bloated serialized notification options with no longer existing constants causing bugs in rails 5.1

clean_notification_options.rb

require_relative 'config/environment'

Notification.includes(:subject).all.each do |n|
  begin
    # Options could have no longer available activerecord/activemodel classes from rails 5.0.0 -> 5.0.6, which will raise an ArgumentError on deserialization
    # Fixing these to use 5.0.7+ smaller serialization format without all the private attributes is too hard, especailly since you can only read their YAML strings
    # and make changes as a string, not as a Hash.
    opts = n.options
  rescue ArgumentError
    new_value = n.subject.try(:name) || n.subject.try(:description)
    
    # We have no option but to blow away whatever was in options and set the subject information to what's in the associated subject object, even if it's been removed.
    puts "Notification: #{n.id} options are not loadable, setting options[:subject] from subject association: #{n.subject_type}: #{n.subject_id} with value: #{new_value}"
    
    # Must use update_all to avoid callbacks and checks on this instance.
    n.class.where(:id => n.id).update_all(:options => {:subject =>  new_value})
    next
  else
    begin
      opts_subject = opts[:subject] 
      opts_subject.reload if opts_subject.respond_to?(:reload)
    rescue ActiveRecord::RecordNotFound
      # Options are readable.  Options[:subject] is a AR::Base object but has been deleted, set the options[:subject] to the name or description
      # from the association subject or the serialized options[:subject] object.
      new_value = n.subject.try(:name) || n.subject.try(:description) || opts[:subject].name || opts[:subject].description
      puts "Notification:  #{n.id} subject, #{n.subject_type}: #{n.subject_id}, no longer exists, setting options[:subject] from serialized options: #{opts[:subject].class.name}[#{opts[:subject].id}] with new value: #{new_value}"
      n.class.where(:id => n.id).update_all(:options => {:subject =>  new_value})
    end
  end
end