Rspec 2 and Rails 3 stubbing / mocking - ruby-on-rails-3

Question

I am currently in the process of migration to rails 3 from rails 2 in a large application. In our functional specs, we have alot of stuff like this:
#model = Factory :model
#child = Factory :child
Model.stub!(:find).and_return(#model)
Child.stub!(:find).and_return(#child)
...
#child.should_receive(:method).twice
The main issue is that if I let it hit DB and get actual instance of child, real :method makes tests too complex (need two big factories) and slow.
In code we use various ways to get items: find, dynamic finders, etc
#model = Model.find(1)
#child = #model.children.find_by_name(name)
How would you advice to move this logic to rails 3? Any advice on another stubbing/mocking library maybe?

Answer 1

Normally you would mock the model inside controller specs:
Model.stub!(:find).and_return(mock_model('Model'))
Child.stub!(:find).and_return(mock_model('Child'))
However, when you've got gem "rspec-rails", "~> 2.0" in your rails 3 app's Gemfile, then the standard rails scaffold generator will use rspec to generate specs for you, so running rails generate scaffold MyResource will generate some example specs for you.
The following is a lightly annotated version of what rails/rspec will generate for controller specs, so I suppose this should be considered "The RSpec Way".
describe AccountsController do
# Helper method that returns a mocked version of the account model.
def mock_account(stubs={})
(#mock_account ||= mock_model(Account).as_null_object).tap do |account|
account.stub(stubs) unless stubs.empty?
end
end
describe "GET index" do
it "assigns all accounts as #accounts" do
# Pass a block to stub to specify the return value
Account.stub(:all) { [mock_account] }
get :index
# Assertions are also made against the mock
assigns(:accounts).should eq([mock_account])
end
end
describe "GET show" do
it "assigns the requested account as #account" do
Account.stub(:find).with("37") { mock_account }
get :show, :id => "37"
assigns(:account).should be(mock_account)
end
end
describe "GET new" do
it "assigns a new account as #account" do
Account.stub(:new) { mock_account }
get :new
assigns(:account).should be(mock_account)
end
end
end