Refactored complex scope

Complex scope has been refactored into an static method. Added tests to
validate this new method.

app/models/poll.rb

@@ -36,13 +36,13 @@ class Poll < ActiveRecord::Base
   scope :published, -> { where('published = ?', true) }
   scope :by_geozone_id, ->(geozone_id) { where(geozones: {id: geozone_id}.joins(:geozones)) }
   scope :public_for_api, -> { all }
-  scope :overlaping_with, lambda { |poll| 
+  scope :sort_for_list, -> { order(:geozone_restricted, :starts_at, :name) }
+
+  def self.overlaping_with(poll)
     where('? < ends_at and ? >= starts_at', poll.starts_at.beginning_of_day, poll.ends_at.end_of_day)
       .where.not(id: poll.id)
       .where(related: poll.related)
-  }
-
-  scope :sort_for_list, -> { order(:geozone_restricted, :starts_at, :name) }
+  end
 
   def title
     name

spec/models/poll/poll_spec.rb

@@ -221,7 +221,6 @@ describe Poll do
   end
 
   describe "#voted_in_booth?" do
-
     it "returns true if the user has already voted in booth" do
       user = create(:user, :level_two)
       poll = create(:poll)
@@ -246,7 +245,30 @@ describe Poll do
 
       expect(poll.voted_in_booth?(user)).not_to be
     end
-
   end
 
+  describe '.overlaping_with' do
+    let(:proposal) { create :proposal }
+    let(:other_proposal) { create :proposal }
+    let(:poll) { create(:poll, related: proposal) }
+    let(:overlaping_poll) { build(:poll, related: proposal, starts_at: poll.starts_at + 1.day, ends_at: poll.ends_at - 1.day) }
+    let(:non_overlaping_poll) { create(:poll, related: proposal, starts_at: poll.ends_at + 1.day, ends_at: poll.ends_at + 31.days) }
+    let(:overlaping_poll_2) { create(:poll, related: other_proposal, starts_at: poll.starts_at + 1.day, ends_at: poll.ends_at - 1.day) }
+
+    it 'a poll can not overlap itself' do
+      expect(Poll.overlaping_with(poll)).not_to include(poll)
+    end
+
+    it 'returns overlaping polls for the same proposal' do
+      expect(Poll.overlaping_with(overlaping_poll)).to include(poll)
+    end
+
+    it 'do not returs non overlaping polls for the same proposal' do
+      expect(Poll.overlaping_with(poll)).not_to include(non_overlaping_poll)
+    end
+
+    it 'do not returns overlaping polls for other proposal' do
+      expect(Poll.overlaping_with(poll)).not_to include(overlaping_poll_2)
+    end
+  end
 end