caboose

In our open source ticket tracker xtt, we have code that looks like this:

has_many :memberships do
  def contexts
    proxy_owner.memberships.sort.group_by &:context
  end
end

Basically, it lets people group their memberships to various projects by a context. So each user can have their own grouping for projects. If you don't have a context for a project, it shows that last, in an implicit 'etc' context. In the tests, we check for this behavior like

it "leaves nil context for last" do
  @contexts = @user.memberships.contexts
  @contexts.last.should == [nil, [memberships(:default)]]
end

However, since rails now returns aggregated association results (such as group_by or total with :group) as an ActiveSupport::OrderedHash, you don't get all those tasty array methods that Rails is so famous for (#last, #second etc).

ActiveSupport::OrderedHash is just some code that duplicates Ruby 1.9's hash functionality.

The easy solution here is to make your results into an array at some point, rewrite your tests, or send a patch to the rails team to mix in the Array monkeypatched code into OrderedHash.

it "leaves nil context for last" do
  @contexts = @user.memberships.contexts
  @contexts.to_a.last.should == [nil, [memberships(:default)]]
end