mastodon/spec/mailers/previews/notification_mailer_preview.rb

# Preview all emails at http://localhost:3000/rails/mailers/notification_mailer
class NotificationMailerPreview < ActionMailer::Preview
  # Preview this email at http://localhost:3000/rails/mailers/notification_mailer/mention
  def mention
    m = Mention.last
    NotificationMailer.mention(m.account, Notification.find_by(activity: m))
  end

  # Preview this email at http://localhost:3000/rails/mailers/notification_mailer/follow
  def follow
    f = Follow.last
    NotificationMailer.follow(f.target_account, Notification.find_by(activity: f))
  end

  # Preview this email at http://localhost:3000/rails/mailers/notification_mailer/favourite
  def favourite
    f = Favourite.last
    NotificationMailer.favourite(f.status.account, Notification.find_by(activity: f))
  end

  # Preview this email at http://localhost:3000/rails/mailers/notification_mailer/reblog
  def reblog
    r = Status.where.not(reblog_of_id: nil).first
    NotificationMailer.reblog(r.reblog.account, Notification.find_by(activity: r))
  end

  # Preview this email at http://localhost:3000/rails/mailers/notification_mailer/digest
  def digest
    NotificationMailer.digest(Account.first, since: 90.days.ago)
  end
end