How to proper test scopes (named scopes)

I just read few posts about "how to test named scopes". I'm asking - why should I use FactoryGirl and create tons of unnecessary objects just to test `order(:position).first`?!

How not to do this

	require 'spec_helper'
	describe Post do
	context '#recent' do
	it 'should return most recent post' do
	_, post = [Factory(:post), Factory(:post)]
	Post.recent.should == post
	end
	end
	context '#for_user' do
	it 'should return only posts created by given user' do
	post1, post2, _ = [Factory(:post, user_id: 1), Factory(:post, user_id: 1), Factory(:post, user_id: 2)]
	Post.for_user(1).should == [post1, post2]
	end
	end
	end

view raw post_spec.rb hosted with ❤ by GitHub

We've just created .. let's count .. 5 objects and made 2 unnecessary db queries

How to do this

	require 'spec_helper'
	describe Post do
	context '#recent' do
	it 'should return most recent post' do
	post = mock_model Post
	Post.should_receive(:order).with('created_at DESC').and_return post
	post.should_receive(:first).and_return post
	Post.recent
	end
	end
	context '#for_user' do
	it 'should return only posts created by given user' do
	post = mock_model Post
	Post.should_receive(:where).with(user_id: 1)
	Post.for_user 1
	end
	end
	end

view raw post_spec.rb hosted with ❤ by GitHub

It's useless to test Rails (it's really proper tested). We need to spec messages that goes between objects and given parameters.