Ruby on rails Resque中出现TypeError，我无法找出原因

我有一个后台任务，它发送一封由Resque处理的电子邮件，该邮件抛出了一个TypeError，我无法找出是什么导致了它

我将任务排队：

Resque.enqueue（ShownUpvoteEvent，self.id）

然后我在worker中处理它：

class ShownUpvoteEvent
  @queue = :email
  def self.perform(event_id)
    UserMailer.shown_upvote_event(event_id).deliver
  end
end

调用

UserMailer

会触发此方法：

def shown_upvote_event(event_id)
  @event = TimelineEvent.find(event_id)
  @user = @event.subject
  @actor = @event.actor
  @song = @event.secondary_subject
  if VideoVote.find_by_user_id_and_video_id(@actor.id, @song.id).value == 1
    @voted = "upvoted"
  else
    @voted = "downvoted"
  end    
  mail(:to => @user.email, :subject => "#{@actor.name} #{@voted} the song you showed to him/her.")
end

Resque显示我成功地将事件对象的id传递到worker中，但是我不知道是什么导致了这个错误

TypeError
错误
无法将字符串转换为整数。

这是堆栈跟踪：

/app/app/mailers/user_mailer.rb:60:in `[]'
/app/app/mailers/user_mailer.rb:60:in `shown_upvote_event'
/app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.0.7/lib/abstract_controller/base.rb:150:in `process_action'
/app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.0.7/lib/abstract_controller/base.rb:119:in `process'
/app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.0.7/lib/abstract_controller/rendering.rb:41:in `process'
/app/.bundle/gems/ruby/1.9.1/gems/actionmailer-3.0.7/lib/action_mailer/old_api.rb:75:in `process'
/app/.bundle/gems/ruby/1.9.1/gems/actionmailer-3.0.7/lib/action_mailer/base.rb:471:in `process'
/app/.bundle/gems/ruby/1.9.1/gems/actionmailer-3.0.7/lib/action_mailer/base.rb:466:in `initialize'
/app/.bundle/gems/ruby/1.9.1/gems/actionmailer-3.0.7/lib/action_mailer/base.rb:450:in `new'
/app/.bundle/gems/ruby/1.9.1/gems/actionmailer-3.0.7/lib/action_mailer/base.rb:450:in `method_missing'
/app/app/workers/send_emails.rb:46:in `perform'

堆栈跟踪指向第60行真的很奇怪，因为似乎不应该调用代码：

def heard_event(event_id)
  @event = TimelineEvent.find(event_id)
  @user = @event.subject
  @actor = @event.actor
  @song = @event.secondary_subject
  showable_video = ShowableVideo.find_by_user_id_and_profile_id_and_video_id(@user.id, @actor.id, @song.id)
  if showable_video.heard == true
  @heard = "had already heard"
  else
    @heard = "had not yet heard"
  end    
  #below is line 60, but this method should not be running
  mail(:to => @user.email, :subject => "#{@actor.name} #{@heard} the song you showed to him/her.")
end

def shown_upvote_event(event_id)
  @event = TimelineEvent.find(event_id)
  @user = @event.subject
  @actor = @event.actor
  @song = @event.secondary_subject
  if VideoVote.find_by_user_id_and_video_id(@actor.id, @song.id).value == 1
  @voted = "upvoted"
  else
    @voted = "downvoted"
  end    
  mail(:to => @user.email, :subject => "#{@actor.name} #{@voted} the song you showed to him/her.")
end

---

@SergioTulentsev我更新了问题的详细信息你确定这是第60行，而不是在修改代码之后吗？运行

VideoVote.find_by_user_id_和\u video_id（@actor.id，@song.id）.class.name

。是否返回

String

？检查。（假设<代码>如果<代码>在第60行。）和主题之外，也许<代码>“{@actor.name}{@heard}你分享的歌曲。”可能更好？@SergioTulentsev是的，这是真正的第60行，除非我疯了