如何测试蒙古范围？

Question

I defined the following User class with scopes :

class User
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Search

  # SCOPES
  scope :all_admins, where( role: :admin)
  scope :recents, order_by(created_at: :desc)
  scope :olders, order_by(created_at: :asc)

  field :role, type: Symbol
end

If I use the following rspec test :

describe 'scopes' do
  let(:admin1)            { Fabricate(:admin) }
  let(:admin2)               { Fabricate(:admin) }

  describe 'recents' do
    it 'should return the admins from most recent to older' do
      User.all_admins.recents.should eq([admin1, admin2])
    end
  end
end

I get the following fail message :

got: #<Mongoid::Criteria
  selector: {"role"=>:admin},
  options:  {:sort=>{"created_at"=>-1}},
  class:    User,
  embedded: false>

So how could I test this scope ?

Answer 1

Mongoid lazy loads, do:

User.all_admins.recents.to_a.should eq([admin1, admin2])

Side notes:

• you should create your scopes as lambdas, it will soon be the norm with Rails4

• I got issues with symbol type in mongo (during migrations), I'd rather use strings

• I'm pretty sure your test will fail since your objects are not created in db ( let is not evaluated until it's called, replace with let! )