如何使用rspec测试Mongoid :: Observer

Question

在一个简单的mongoid数据模型上,用户有很多评论,我想在用户写至少一条评论时给用户一个特定的徽章.所以我建立了一个像这样的观察者:

class CommentBadgeObserver < Mongoid::Observer
  observe :comment

  def after_create(comment)
    CommentBadge.check_conditions_for(comment.user)
  end
end

class CommentBadge < Badge
  def self.check_conditions_for(user)
    if user.comments.size > 1
      badge = CommentBadge.create(:title => "Comment badge")
      user.award(badge)
    end
  end
end

user.award方法:

def award(badge)
  self.badges << badge
  self.save
end

以下测试失败(但我想这是正常的,因为观察者在后台执行？)

it 'should award the user with comment badge' do
    @comment = Factory(:comment, :user => @user)
    @user.badges.count.should == 1
    @user.badges[0].title.should == "Comment badge"
end

什么是验证此行为的最佳方法？

Answer 1

我有一个独立的代码改编(见下文).我不得不做三个小改动,让它按照你期望的方式工作.

要使Observer正常工作,您必须实例化它.在我的例子中,我需要添加以下行:

Mongoid.observers = CommentBadgeObserver
Mongoid.instantiate_observers

在Rails中你可以实现相同的功能,将它添加到config/application.rb(根据文档):

config.mongoid.observers = :comment_badge_observer

我觉得还有一个小逻辑错误的CommentBadge.check_conditions_for,则> 1应该是> 0.

最后,我更改了User#award保存徽章而不是用户的方法,因为存储关系的"外键"字段位于徽章一侧.

class Comment
  include Mongoid::Document
  field :name
  belongs_to :user
end

class CommentBadgeObserver < Mongoid::Observer
  observe :comment

  def after_create(comment)
    CommentBadge.check_conditions_for(comment.user)
  end
end

class Badge
  include Mongoid::Document
  field :title
  belongs_to :user
end

class CommentBadge < Badge
  def self.check_conditions_for(user)
    if user.comments.size > 0
      badge = CommentBadge.create!(:title => "Comment badge")
      user.award(badge)
    end
  end
end

class User 
  include Mongoid::Document
  field :first_name
  has_many :comments
  has_many :badges

  def award(badge)
    self.badges << badge
    badge.save!
  end
end

Factory.define(:user) do |u|
  u.first_name 'Bob'
end

Factory.define(:comment) do |c|
  c.name 'Some comment...'
end

# Observers need to be instantiated
Mongoid.observers = CommentBadgeObserver
Mongoid.instantiate_observers

describe CommentBadgeObserver do
  it 'should create badges' do
    @user = Factory.build(:user)
    @comment = Factory(:comment, :user => @user)
    @user.badges.count.should == 1
    @user.badges[0].title.should == "Comment badge"
  end
end