A while back there was either a feature request in the rspec tracker, or a suggestion on one of the rspec mailing lists, for a feature to DRY up controller specs.

The idea was that this pattern feels a bit clunky:

<code>describe PersonController, "handling failed POST to create" do
def do_post
  post :create, invalid_arguments
end

it "should redisplay the create form" do
  do_post
  response.should render_template("people/new")
end

it "should try to create a Person" do
  Person.should_receive(:create).with(invalid_arguments).and_return(false)
  do_post
end
end
</code>

And it would be nice to have something that was more expressive using tags like this:

<code>describe PersonController, "handling failed POST to create" do
def do_post
  post :create, invalid_arguments
end

it "should redisplay the create form", :after => :do_post do
  response.should render_template("people/new")
end

it "should try to create a Person", :before => :do_post do
  Person.should_receive(:create).with(invalid_arguments).and_return(false)
end
end
</code>

I didn’t add this to rspec_on_rails because I personally find it harder to read. It also doesn’t support situations where you want to stub something before the action and then set a state-based expecation after the action.

But the problem is still present, and it would be nice to have something a bit less clunky.

Well – here’s what I’ve been experimenting with. This is NOT part of RSpec, and I may not want to include it in RSpec because I think it’s somewhat particular to my personal style (as opposed to a style that I think is “right” for BDD), but it’s easy enough to add to your own projects.

Here’s what the specs look like:

<code>describe PersonController, "handling failed POST to create" do
def do_post
  post :create, invalid_arguments
end

it "should redisplay the create form" do
  after_post do
    response.should render_template("people/new")
  end
end

it "should try to create a Person" do
  during_post do
    Person.should_receive(:create).with(invalid_arguments).and_return(false)
  end
end
end
</code>

I really like this even though it actually turns out to be a bit more verbose. I think it speaks very clearly about what is going on – especially “during_post”, which describes very well when the Person.should_receive the :create message.

Here’s the code in spec_helper.rb that supports this pattern:

<code>[:get, :post, :put, :delete, :render].each do |action|
eval %Q{
  def before_#{action}
    yield
    do_#{action}
  end
  alias during_#{action} before_#{action}
  def after_#{action}
    do_#{action}
    yield
  end
}
end
</code>

This supports controller and view specs (hence including :render).

Please try it out and let me know what you think.