如何测试has_many：through关联，该关联在与Factory Girl in Rails的关联上也具有validates_presence_of验证？

Question

I'm trying to test a model with Factory Girl that has a validates_presence_of on a has_many :through association with. Although the form is working fine and I can write a test that fills out the form manually, I'm not able to get a valid factory. This test keeps failing:

it "has a valid work factory" do
    work = FactoryGirl.build(:work)
    work.should be_valid
end

Here's the error message:

Work has a valid work factory
     Failure/Error: work.should be_valid
       expected #<Work id: nil, name: "Client Website", date: "2013-06-03 16:13:08", client: #<Client id: 1, name: "Client Number 4", client_code: "CN4", created_at: "2013-06-04 16:13:12", updated_at: "2013-06-04 16:13:12">, description: "A great new website for the client.", image: "/image.jpg", service: "Web", featured: true, created_at: nil, updated_at: nil> to be valid, but got errors: Client can't be blank

Here's my factories.rb file:

FactoryGirl.define do
  factory :user do
    sequence(:email)        { |n| "person_#{n}@example.com"}
    password                "secret"
    password_confirmation   "secret"

    factory :admin do
      after(:create) {|user| user.add_role(:admin)}
    end
  end

  factory :client do
    sequence(:name)          { |n| "Client Number #{n}"}
    sequence(:client_code)   { |n| "CN#{n}"}
  end

  factory :work do
    name            "Client Website"
    client
    date            1.day.ago
    description     "A great new website for the client."
    image           "/image.jpg"
    service         "Web"
    featured        true
  end  
end

My work model:

class Work < ActiveRecord::Base
  attr_accessible :client, :client_ids, :date, :description, :featured, :image, :name, :service

  validates_presence_of :client_ids
  validates_presence_of :date, :image, :name
  validates_length_of   :description, :in => 5..500, :allow_blank => true
  validates_length_of   :name, :in => 5..50

  has_many :postings
  has_many :clients, :through => :postings  
end

My client model:

class Client < ActiveRecord::Base
  attr_accessible :client_code, :name

  validates_presence_of     :client_code, :name
  validates_uniqueness_of   :name
  validates_length_of       :client_code, :is => 3
  validates_length_of       :name, :in => 5..50

  has_many  :postings
  has_many  :works, :through => :postings  
end

It seems like this test should pass because the factory is getting built with a client. But I'm not sure why that validation is causing an error.

Answer 1

The error message says expected ..... to be valid, but got errors: Client can't be blank

work = FactoryGirl.build(:work) # this returns an unsaved object

By using build you haven't saved the object. The object is nil . If an object is nil it is blank

You want to save the object on creation like this

work = FactoryGirl.create(:work) # this returns a saved object

Now

work.should be_valid

should pass

UPDATE:

I didn't look closely enough at your `factories.rb'

factory :work do
  name            "Client Website"
  client
  date            1.day.ago
  description     "A great new website for the client."
  image           "/image.jpg"
  service         "Web"
  featured        true
end  

your client attribute in the work factory is literally blank. This wont pass validation and wont save the object. Fill in client in the factory or pass in something on creation like this

work = FactoryGirl.create(:work, client: "fill in with client")