Default_scope in Rails model when testing with Rspec using FactoryGirl - ruby-on-rails

Question

I'm developing a blog in Rails and I'm stuck when I was trying to test the default scope I added to the Post model in order to have the posts in descending order of their creation date.
Post code:
class Post < ActiveRecord::Base
attr_accessible :content, :name, :title
validates :title, presence: true,uniqueness: true
validates :name, presence: true
validates :content, presence: true
default_scope order: "posts.created_at DESC"
end
Rspec code:
describe "Posts descending order of creation date" do
let(:older_post) do
FactoryGirl.create(:post, created_at: 1.day.ago)
end
let(:newer_post) do
FactoryGirl.create(:post, created_at: 1.hour.ago)
end
it "should have the 2 posts in desc order" do
Post.all.should == [newer_post, older_post]
end
end
FactoryGirl definition
FactoryGirl.define do
factory :post do
sequence(:title) { |n| "A book #{n}" }
name "Johnny"
content "Lorem Ipsum"
end
end
The output
.....F...
Failures:
1) Post Posts descending order of creation date should have the 2 posts in desc order
Failure/Error: Post.all.should == [newer_post, older_post]
expected: [#<Post id: 1, name: "Johnny", title: "A book 1", content: "Lorem Ipsum", created_at: "2013-05-01 14:44:45", updated_at: "2013-05-01 15:44:45">, #<Post id: 2, name: "Johnny", title: "A book 2", content: "Lorem Ipsum", created_at: "2013-04-30 15:44:45", updated_at: "2013-05-01 15:44:45">]
got: [] (using ==)
Diff:
## -1,3 +1,2 ##
-[#<Post id: 1, name: "Johnny", title: "A book 1", content: "Lorem Ipsum", created_at: "2013-05-01 14:44:45", updated_at: "2013-05-01 15:44:45">,
- #<Post id: 2, name: "Johnny", title: "A book 2", content: "Lorem Ipsum", created_at: "2013-04-30 15:44:45", updated_at: "2013-05-01 15:44:45">]
+[]
# ./spec/models/post_spec.rb:54:in `block (3 levels) in <top (required)>'
Finished in 1.03 seconds
9 examples, 1 failure
Failed examples:
rspec ./spec/models/post_spec.rb:53 # Post Posts descending order of creation date should have the 2 posts in desc order
I also want to mention that when I type Post.all in the Rails console, I get the records in descending order ( so as I wanted them).
Can someone give me a suggestion on what the problem might be?

Answer 1

Please know that let is evaluated lazily in RSpec. This often creates problem in such scenarios where ordering is concerned.
Try these two alternatives:
describe "Posts descending order of creation date" do
let!(:older_post) do
FactoryGirl.create(:post, created_at: 1.day.ago)
end
let!(:newer_post) do
FactoryGirl.create(:post, created_at: 1.hour.ago)
end
it "should have the 2 posts in desc order" do
Post.all.should == [newer_post, older_post]
end
end
Note, the use of let! instead of let.
Or, use before as:
describe "Posts descending order of creation date" do
it "should have the 2 posts in desc order" do
#older_post = FactoryGirl.create(:post, created_at: 1.day.ago)
#newer_post = FactoryGirl.create(:post, created_at: 1.hour.ago)
Post.all.should == [#newer_post, #older_post]
end
end
Do let me know if it works or not. :)