Forum: RSpec testing named_scope

Hi! I'm new to rspec and was wondering how named_scopes are usually
tested? Is it enough to test that it's defined? or do you need to test
the behavior as well? I've been reading around and this seems to be
the tester's choice, i just want to get people's opinion on this :D

On Sun, Jan 17, 2010 at 8:17 PM, Nin <npdepolonia@gmail.com> wrote:

> Hi! I'm new to rspec and was wondering how named_scopes are usually
> tested? Is it enough to test that it's defined? or do you need to test
> the behavior as well? I've been reading around and this seems to be
> the tester's choice, i just want to get people's opinion on this :D
>

_Specify_ the behaviour, don't _test_ the implementation. The fact that 
a
method is defined with a named_scope declaration is irrelevant to the
behaviour.

One reason for this is keeping things decoupled. Consider the fact that
named_scope just changed to scope today [1]. If your specs specify a 
call to
named_scope, they'll have to change, whereas if they they only specify 
the
name you define then you'll only need to update the implementation when 
you
upgrade.

[1]
http://github.com/rails/rails/commit/d60bb0a9e4be2ac0a9de9a69041a4ddc2e0cc914

That all make sense?

class User < ActiveRecord::Base
  named_scope :admins, :conditions => {:admin => true}
end

describe User, "admins" do
  it "should include users with admin flag" do
    admin = User.create! :admin => true
    User.admin.should include(admin)
  end

  it "should not include users without admin flag" do
    admin = User.create! :admin => false
    User.admin.should_not include(admin)
  end
end

On Mon, Jan 18, 2010 at 4:01 AM, Pat Maddox <mailinglists@patmaddox.com> 
wrote:
> describe User, "admins" do
>  it "should include users with admin flag" do
>    admin = User.create! :admin => true
>    User.admin.should include(admin)
>  end
>
>  it "should not include users without admin flag" do
>    admin = User.create! :admin => false
>    User.admin.should_not include(admin)
>  end
> end

Small style matter, but I've leaning towards more declarative sounding
example names:

describe User, ".admins" do
  it "includes users with admin flag" do
    admin = User.create! :admin => true
    User.admin.should include(admin)
  end

  it "excludes users without admin flag" do
    non_admin = User.create! :admin => false
    User.admin.should_not include(non_admin)
  end
end

class User < ActiveRecord::Base
  named_scope :admins, :conditions => {:admin => true}
end

We still have 'should' in the examples, but this produces more
'spec-like' output:

User.admins
  includes users with admin flag
  excludes users without admin flag

FWIW,
David

On Mon, Jan 18, 2010 at 5:17 AM, David Chelimsky 
<dchelimsky@gmail.com>wrote:

> On Mon, Jan 18, 2010 at 4:01 AM, Pat Maddox <mailinglists@patmaddox.com>
> wrote:
>

...


> >  it "should not include users without admin flag" do
>     admin = User.create! :admin => true
>   named_scope :admins, :conditions => {:admin => true}
> end
>
> We still have 'should' in the examples, but this produces more
> 'spec-like' output:
>
> User.admins
>   includes users with admin flag
>   excludes users without admin flag


I agree, David. I've been omitting "should" from the beginning. For me, 
it
made the start of every example look too similar.

Regards,
Craig

On Sun, Jan 17, 2010 at 9:17 PM, Nin <npdepolonia@gmail.com> wrote:
> Hi! I'm new to rspec and was wondering how named_scopes are usually
> tested? Is it enough to test that it's defined? or do you need to test
> the behavior as well? I've been reading around and this seems to be
> the tester's choice, i just want to get people's opinion on this :D

While this is focused on shoulda, I still found it helpful for
demonstrating how to properly deal with testing named_scopes.

http://robots.thoughtbot.com/post/200254501/testing-named-scopes

Best regards,
Michael Guterl

David Chelimsky wrote:
>>  named_scope :admins, :conditions => {:admin => true}
>>    User.admin.should_not include(admin)
>     User.admin.should include(admin)
> end
>   
Another small style matter.. I like using the :: notation for class
methods as that is what the documentation tools tend to use (RDoc and 
Yard):

describe User, "::admins" do
...
...
end


On the topic of RSpec as a form of documentation has anyone used the
yard-doc rspec plugin?  It appears to be pretty limited ATM but seems
very cool with a lot of potential.  Just like Ioke's docs it embeds the
specs as part of the documentation with the option to view the source.
Here is the example from the projects home page:

http://lsegal.github.com/yard-spec-plugin/String.html#pig_latin-instance_method

-Ben

Nin wrote:
> Hi! I'm new to rspec and was wondering how named_scopes are usually
> tested? Is it enough to test that it's defined? or do you need to test
> the behavior as well? I've been reading around and this seems to be
> the tester's choice, i just want to get people's opinion on this :D

Here is my approach: 
http://gusiev.com/2010/07/bdd-rspec-matcher-to-test-named_scope-scoped-rails-3/
It is a little advanced. Hopefully you will get the idea.