Question

I have this code for creating a topic and post in a forum application in Rails 3.1:

def create
  @topic = Topic.new(:name => params[:topic][:name], :last_post_at => Time.now)
  @topic.forum_id = params[:topic][:forum_id]
  @topic.user = current_user

  if @topic.save
    @post = Post.new(:content => params[:post][:content])
    @post.topic = @topic
    @post.user = current_user

    @post.save!
    ...

When posting to the create method via the corresponding form, the topic and the post are created and both save calls are successful.

When I call the create method via a functional test, the topic is saved but the post has validation errors.

ActiveRecord::RecordInvalid: Validation failed: 
app/controllers/topics_controller.rb:23:in `create'
test/functional/topics_controller_test.rb:26:in `block in <class:TopicsControllerTest>'

The test looks like this:

test "should create topic" do
  post :create, :topic => {:name => "New topic", :forum_id => forums(:one).id}, :post => {:content => "Post content"}
end

(current_user is logged in via a setup method.)

When I display the errors of the post object via the debugger or with @post.errors.full_messages, the error array is empty.

The Post model looks like this:

class Post < ActiveRecord::Base
  attr_accessible :content

  belongs_to :topic
  belongs_to :user
end

And the Topic model:

class Topic < ActiveRecord::Base
  belongs_to :user
  belongs_to :last_poster, class_name: 'User'

  attr_accessible :name, :last_poster_id, :last_post_at

  belongs_to :forum
  has_many :posts, :dependent => :destroy
end

How can I find out what is causing the validation error?

Answer 1

The problem was that I used mocha’s Post.any_instance.stubs(:valid?).returns(false) in a test that was executed before my failing test.

Apparently, you have to restore the original behavior before proceeding with other tests by calling Post.any_instance.unstub(:valid?).