rspec users - Apr 2009 - [RSpec] Clarification on using shared_examples_for on a Rails Controller

On Wed, Apr 22, 2009 at 12:04 PM, Stephen H. Gerstacker
<stephen at shortround.net> wrote:
> I have a Rails controller that I am using ''before_filter''
on certain actions
> to assign some extra variables.? I noticed the
''shared_examples_for'' method
> and thought this would be a good way to test that the given actions are
> loading what they need.? I wrote the following:
>
> shared_examples_for ''pages showing the yearly archive'' do
>
> ??? it ''should assign a list of yearly archives'' do
> ????? Factory.create(:post, :published_at => Time.local(2009,02,01))
> ????? Factory.create(:post, :published_at => Time.local(2009,01,01))
> ????? Factory.create(:post, :published_at => Time.local(2008,01,01))
> ????? Factory.create(:post, :published_at => Time.local(2007,01,01))
> ????? Factory.create(:post, :published_at => Time.local(2001,01,01))
>
> ????? get :index
>
> ????? assigns[:years].should == [ 2009, 2008, 2007, 2001 ]
> ??? end
>
> ? end
>
> The problem is, it is specific to the ''index'' action.? I
can''t use the
> ''it_should_behave_like "pages showing the yearly
archive"'' for other
> actions.
>
> Am I just doing this wrong or is there a way to fix this?
Shared examples don''t support parameterization, but macros do. Try
something like this:

module Macros
  def shows_yearly_archive_for(requests={})
    requests.keys.each do |action|
      it "should assign a list of yearly archives on
#{requests[action]}  #{action}" do
        Factory.create(:post, :published_at => Time.local(2009,02,01))
        Factory.create(:post, :published_at => Time.local(2009,01,01))
        Factory.create(:post, :published_at => Time.local(2008,01,01))
        Factory.create(:post, :published_at => Time.local(2007,01,01))
        Factory.create(:post, :published_at => Time.local(2001,01,01))

        send requests[action], action

        assigns[:years].should == [ 2009, 2008, 2007, 2001 ]
      end
    end
  end
end

describe SomeController do
  extend Macros
  shows_yearly_archive_for :index => :get
end

You can also extend with Macros from the config in spec_helper:

Spec::Runner.configure {|c| c.extend(Macros, :type => :controller)}

HTH,
David

ps - completely un-tested - that was off the top of my head

>
> - Stephen H. Gerstacker
>
> _______________________________________________
> rspec-users mailing list
> rspec-users at rubyforge.org
> http://rubyforge.org/mailman/listinfo/rspec-users
>

On Wed, Apr 22, 2009 at 10:04 AM, Stephen H. Gerstacker
<stephen at shortround.net> wrote:
> I have a Rails controller that I am using ''before_filter''
on certain actions
> to assign some extra variables.? I noticed the
''shared_examples_for'' method
> and thought this would be a good way to test that the given actions are
> loading what they need.? I wrote the following:
>
> shared_examples_for ''pages showing the yearly archive'' do
>
> ??? it ''should assign a list of yearly archives'' do
> ????? Factory.create(:post, :published_at => Time.local(2009,02,01))
> ????? Factory.create(:post, :published_at => Time.local(2009,01,01))
> ????? Factory.create(:post, :published_at => Time.local(2008,01,01))
> ????? Factory.create(:post, :published_at => Time.local(2007,01,01))
> ????? Factory.create(:post, :published_at => Time.local(2001,01,01))
>
> ????? get :index
>
> ????? assigns[:years].should == [ 2009, 2008, 2007, 2001 ]
> ??? end
>
> ? end
>
> The problem is, it is specific to the ''index'' action.? I
can''t use the
> ''it_should_behave_like "pages showing the yearly
archive"'' for other
> actions.
Assign the action to an instance variable and set it to the desired
value in a before(:all) in each of the sharers. In the shared example,
do get @action.

///ark

----- Original Message ----
> From: David Chelimsky <dchelimsky at gmail.com>
> Shared examples don''t support parameterization, but macros do. Try
> something like this:
> 
> module Macros
>   def shows_yearly_archive_for(requests={})
[...]
>   end
> end
> 
> describe SomeController do
>   extend Macros
>   shows_yearly_archive_for :index => :get
> end

Nice.  This must be newish (I see it in book beta4 - good!).  I''d been
using callbacks defined in the example group next to it_should_behave_like() to
get any relevant parameters.  A bit icky, I''ll admit.  So I can just
pass the details from the callback directly to the macro, when I port it/them. 
Sweet.

I''ve been using a pattern for my shared example groups, similar to one
I correlate (erroneously?) to a Ben Mabey post.  The original pattern: do_foo(),
where foo is get, post, whatever and the shared example probes the calling
example group to find which one is relevant.

My variation is do_action(), where the example group directly defines
do_action() in whatever way is suitable to the example group (using instance
variables set by before blocks, etc).  This method could be defined usefully by
either a Controller example group or a Model example group.

I feel like even when using macros, I''d want to continue using my
do_action() pattern.  But maybe I have a hammer and so I''m looking for
a nail.

Is there another approach that gives different/better value when using macros?

Thanks,

Randy