add scope support

README.md

@@ -3,7 +3,7 @@
 [![Build Status](https://travis-ci.org/wbotelhos/rating.svg)](https://travis-ci.org/wbotelhos/rating)
 [![Gem Version](https://badge.fury.io/rb/rating.svg)](https://badge.fury.io/rb/rating)
 
-A true Bayesian rating system with cache enabled.
+A true Bayesian rating system with scope and cache enabled.
 
 ## JS Rating?
 
@@ -71,7 +71,7 @@ class User < ApplicationRecord
 end
 ```
 
-Now this model can vote or be voted.
+Now this model can vote or receive votes.
 
 ### rate
 
@@ -175,6 +175,103 @@ Article.order_by_rating :average, :asc
 
 It will return a collection of resource ordered by `Rating` table data.
 
+### Scope
+
+All methods support scope query, since you may want to vote on items of a resource instead the resource itself.
+Let's say an article belongs to one or more categories and you want to vote on some categories of this article.
+
+```ruby
+category_1 = Category.first
+category_2 = Category.second
+author     = User.last
+resource   = Article.last
+```
+
+In this situation you should scope the vote of article with some category:
+
+**rate**
+
+```ruby
+author.rate resource, 3, scopeable: category_1
+author.rate resource, 5, scopeable: category_2
+```
+
+Now `article` has a rating for `category_1` and another one for `category_2`.
+
+**rating**
+
+Recovering the rating values for article, we have:
+
+```ruby
+author.rating
+# nil
+```
+
+But using the scope to make the right query:
+
+```ruby
+author.rating scope: category_1
+# { average: 3, estimate: 3, sum: 3, total: 1 }
+
+author.rating scope: category_2
+# { average: 5, estimate: 5, sum: 5, total: 1 }
+```
+
+**rated**
+
+On the same way you can find your rates with a scoped query:
+
+```ruby
+user.rated scope: category_1
+# { value: 3, scopeable: category_1 }
+```
+
+**rates**
+
+The resource still have the power to consult its rates:
+
+```ruby
+article.rates scope: category_1
+# { value: 3, scopeable: category_1 }
+
+article.rates scope: category_2
+# { value: 3, scopeable: category_2 }
+```
+
+**order_by_rating**
+
+To order the rating you do the same thing:
+
+```ruby
+Article.order_by_rating scope: category_1
+```
+
+### Records
+
+Maybe you want to recover all records with or without scope, so you can add the suffix `_records` on relations:
+
+```ruby
+category_1 = Category.first
+category_2 = Category.second
+author     = User.last
+resource   = Article.last
+
+author.rate resource, 1
+author.rate resource, 3, scopeable: category_1
+author.rate resource, 5, scopeable: category_2
+
+author.rating_records
+# { average: 1, estimate: 1, scopeable: nil       , sum: 1, total: 1 },
+# { average: 3, estimate: 3, scopeable: category_1, sum: 3, total: 1 },
+# { average: 5, estimate: 5, scopeable: category_2, sum: 5, total: 1 }
+
+user.rated_records
+# { value: 1 }, { value: 3, scopeable: category_1 }, { value: 5, scopeable: category_2 }
+
+article.rates_records
+# { value: 1 }, { value: 3, scopeable: category_1 }, { value: 5, scopeable: category_2 }
+```
+
 ## Love it!
 
 Via [PayPal](https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=X8HEP2878NDEG&item_name=rating) or [Gratipay](https://gratipay.com/rating). Thanks! (:

lib/generators/rating/templates/db/migrate/create_rating_tables.rb

@@ -6,13 +6,14 @@ class CreateRatingTables < ActiveRecord::Migration[5.0]
       t.decimal :value, default: 0, precision: 17, scale: 14
 
       t.references :author   , index: true, null: false, polymorphic: true
-      t.references :resource, index: true, null: false, polymorphic: true
+      t.references :resource , index: true, null: false, polymorphic: true
+      t.references :scopeable, index: true, null: true , polymorphic: true
 
       t.timestamps null: false
     end
 
-    add_index :rating_rates, %i[author_id author_type resource_id resource_type],
+    add_index :rating_rates, %i[author_id author_type resource_id resource_type scopeable_id scopeable_type],
-      name:   :index_rating_rates_on_author_and_resource,
+      name:   :index_rating_rates_on_author_and_resource_and_scopeable,
       unique: true
 
     create_table :rating_ratings do |t|
@@ -21,11 +22,14 @@ class CreateRatingTables < ActiveRecord::Migration[5.0]
       t.integer :sum     , default: 0, mull: false
       t.integer :total   , default: 0, mull: false
 
-      t.references :resource, index: true, null: false, polymorphic: true
+      t.references :resource , index: true, null: false, polymorphic: true
+      t.references :scopeable, index: true, null: true , polymorphic: true
 
       t.timestamps null: false
     end
 
-    add_index :rating_ratings, %i[resource_id resource_type], unique: true
+    add_index :rating_ratings, %i[resource_id resource_type scopeable_id scopeable_type],
+      name:   :index_rating_rating_on_resource_and_scopeable,
+      unique: true
   end
 end

lib/rating/models/rating/extension.rb

@@ -5,16 +5,28 @@ module Rating
     extend ActiveSupport::Concern
 
     included do
-      def rate(resource, value, author: self)
+      def rate(resource, value, author: self, scope: nil)
-        Rate.create author: author, resource: resource, value: value
+        Rate.create author: author, resource: resource, scopeable: scope, value: value
       end
 
-      def rate_for(resource)
+      def rate_for(resource, scope: nil)
-        Rate.rate_for author: self, resource: resource
+        Rate.rate_for author: self, resource: resource, scopeable: scope
       end
 
-      def rated?(resource)
+      def rated?(resource, scope: nil)
-        !rate_for(resource).nil?
+        !rate_for(resource, scope: scope).nil?
+      end
+
+      def rates(scope: nil)
+        rates_records.where scopeable: scope
+      end
+
+      def rated(scope: nil)
+        rated_records.where scopeable: scope
+      end
+
+      def rating(scope: nil)
+        rating_records.find_by scopeable: scope
       end
     end
 
@@ -22,23 +34,30 @@ module Rating
       def rating
         after_create { Rating.find_or_create_by resource: self }
 
-        has_one :rating,
+        has_many :rating_records,
           as:         :resource,
           class_name: '::Rating::Rating',
           dependent:  :destroy
 
-        has_many :rates,
+        has_many :rates_records,
           as:         :resource,
           class_name: '::Rating::Rate',
           dependent:  :destroy
 
-        has_many :rated,
+        has_many :rated_records,
           as:         :author,
           class_name: '::Rating::Rate',
           dependent:  :destroy
 
-        scope :order_by_rating, ->(column = :estimate, direction = :desc) {
+        scope :order_by_rating, ->(column = :estimate, direction = :desc, scope: nil) {
-          includes(:rating).order("#{Rating.table_name}.#{column} #{direction}")
+          scope_values = {
+            scopeable_id:   scope&.id,
+            scopeable_type: scope&.class&.base_class&.name
+          }
+
+          includes(:rating_records)
+            .where(Rating.table_name => scope_values)
+            .order("#{Rating.table_name}.#{column} #{direction}")
         }
       end
     end

lib/rating/models/rating/rate.rb

@@ -7,18 +7,19 @@ module Rating
     after_save :update_rating
 
     belongs_to :author   , polymorphic: true
-    belongs_to :resource, polymorphic: true
+    belongs_to :resource , polymorphic: true
+    belongs_to :scopeable, polymorphic: true
 
     validates :author, :resource, :value, presence: true
     validates :value, numericality: { greater_than_or_equal_to: 1, less_than_or_equal_to: 100 }
 
     validates :author_id, uniqueness: {
       case_sensitive: false,
-      scope:          %i[author_type resource_id resource_type]
+      scope:          %i[author_type resource_id resource_type scopeable_id scopeable_type]
     }
 
-    def self.create(author:, resource:, value:)
+    def self.create(author:, resource:, scopeable: nil, value:)
-      record = find_or_initialize_by(author: author, resource: resource)
+      record = find_or_initialize_by(author: author, resource: resource, scopeable: scopeable)
 
       return record if record.persisted? && value == record.value
 
@@ -28,14 +29,14 @@ module Rating
       record
     end
 
-    def self.rate_for(author:, resource:)
+    def self.rate_for(author:, resource:, scopeable: nil)
-      find_by author: author, resource: resource
+      find_by author: author, resource: resource, scopeable: scopeable
     end
 
     private
 
     def update_rating
-      ::Rating::Rating.update_rating resource
+      ::Rating::Rating.update_rating resource, scopeable
     end
   end
 end

lib/rating/models/rating/rating.rb

@@ -4,30 +4,34 @@ module Rating
   class Rating < ActiveRecord::Base
     self.table_name = 'rating_ratings'
 
-    belongs_to :resource, polymorphic: true
+    belongs_to :resource , polymorphic: true
+    belongs_to :scopeable, polymorphic: true
 
     validates :average, :estimate, :resource, :sum, :total, presence: true
     validates :average, :estimate, :sum, :total, numericality: true
 
     class << self
-      def averager_data(resource)
+      def averager_data(resource, scopeable)
-        total_count    = how_many_resource_received_votes_sql?
+        total_count    = how_many_resource_received_votes_sql?(distinct: false, scopeable: scopeable)
-        distinct_count = how_many_resource_received_votes_sql?(distinct: true)
+        distinct_count = how_many_resource_received_votes_sql?(distinct: true , scopeable: scopeable)
+        values         = { resource_type: resource.class.base_class.name }
+
+        values[:scopeable_type] = scopeable.class.base_class.name unless scopeable.nil?
 
         sql = %(
           SELECT
             (#{total_count} / CAST(#{distinct_count} AS float)) count_avg,
             COALESCE(AVG(value), 0)                             rating_avg
           FROM #{rate_table_name}
-          WHERE resource_type = :resource_type
+          WHERE resource_type = :resource_type and #{scope_type_query(scopeable)}
         ).squish
 
-        execute_sql [sql, resource_type: resource.class.base_class.name]
+        execute_sql [sql, values]
       end
 
-      def data(resource)
+      def data(resource, scopeable)
-        averager = averager_data(resource)
+        averager = averager_data(resource, scopeable)
-        values   = values_data(resource)
+        values   = values_data(resource, scopeable)
 
         {
           average:  values.rating_avg,
@@ -37,22 +41,31 @@ module Rating
         }
       end
 
-      def values_data(resource)
+      def values_data(resource, scopeable)
+        scope_query = if scopeable.nil?
+                        'scopeable_type is NULL and scopeable_id is NULL'
+                      else
+                        'scopeable_type = ? and scopeable_id = ?'
+                      end
+
         sql = %(
           SELECT
             COALESCE(AVG(value), 0) rating_avg,
             COALESCE(SUM(value), 0) rating_sum,
             COUNT(1)                rating_count
           FROM #{rate_table_name}
-          WHERE resource_type = ? and resource_id = ?
+          WHERE resource_type = ? and resource_id = ? and #{scope_query}
         ).squish
 
-        execute_sql [sql, resource.class.base_class.name, resource.id]
+        values = [sql, resource.class.base_class.name, resource.id]
+        values += [scopeable.class.base_class.name, scopeable.id] unless scopeable.nil?
+
+        execute_sql values
       end
 
-      def update_rating(resource)
+      def update_rating(resource, scopeable)
-        record = find_or_initialize_by(resource: resource)
+        record = find_or_initialize_by(resource: resource, scopeable: scopeable)
-        result = data(resource)
+        result = data(resource, scopeable)
 
         record.average  = result[:average]
         record.sum      = result[:sum]
@@ -78,19 +91,23 @@ module Rating
         Rate.find_by_sql(sql).first
       end
 
-      def how_many_resource_received_votes_sql?(distinct: false)
+      def how_many_resource_received_votes_sql?(distinct:, scopeable:)
         count = distinct ? 'COUNT(DISTINCT resource_id)' : 'COUNT(1)'
 
         %((
           SELECT #{count}
           FROM #{rate_table_name}
-          WHERE resource_type = :resource_type
+          WHERE resource_type = :resource_type and #{scope_type_query(scopeable)}
         ))
       end
 
       def rate_table_name
         @rate_table_name ||= Rate.table_name
       end
+
+      def scope_type_query(scopeable)
+        scopeable.nil? ? 'scopeable_type is NULL' : 'scopeable_type = :scopeable_type'
+      end
     end
   end
 end

rating.gemspec

@@ -8,14 +8,14 @@ require 'rating/version'
 
 Gem::Specification.new do |spec|
   spec.author      = 'Washington Botelho'
-  spec.description = 'A true Bayesian rating system with cache enabled.'
+  spec.description = 'A true Bayesian rating system with scope and cache enabled.'
   spec.email       = 'wbotelhos@gmail.com'
   spec.files       = Dir['lib/**/*'] + %w[CHANGELOG.md LICENSE README.md]
   spec.homepage    = 'https://github.com/wbotelhos/rating'
   spec.license     = 'MIT'
   spec.name        = 'rating'
   spec.platform    = Gem::Platform::RUBY
-  spec.summary     = 'A true Bayesian rating system with cache enabled.'
+  spec.summary     = 'A true Bayesian rating system with scope and cache enabled.'
   spec.test_files  = Dir['spec/**/*']
   spec.version     = Rating::VERSION
 

spec/factories/article.rb

@@ -2,6 +2,6 @@
 
 FactoryBot.define do
   factory :article do
-    sequence(:name) { |i| "Name #{i}" }
+    sequence(:name) { |i| "Article #{i}" }
   end
 end

spec/factories/category.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :category do
+    sequence(:name) { |i| "Category #{i}" }
+  end
+end

spec/factories/user.rb

@@ -2,6 +2,6 @@
 
 FactoryBot.define do
   factory :user do
-    sequence(:name) { |i| "Name #{i}" }
+    sequence(:name) { |i| "User #{i}" }
   end
 end

spec/models/extension/after_create_spec.rb

@@ -12,6 +12,7 @@ RSpec.describe Rating::Extension, ':after_create' do
       expect(rating.average).to   eq 0
       expect(rating.estimate).to  eq 0
       expect(rating.resource).to  eq user
+      expect(rating.scopeable).to eq nil
       expect(rating.sum).to       eq 0
       expect(rating.total).to     eq 0
     end

spec/models/extension/order_by_rating_spec.rb

@@ -3,6 +3,8 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Extension, ':order_by_rating' do
+  let!(:category) { create :category }
+
   let!(:user_1) { create :user }
   let!(:user_2) { create :user }
 
@@ -15,6 +17,9 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
     create :rating_rate, author: user_1, resource: article_2, value: 11
     create :rating_rate, author: user_1, resource: article_3, value: 10
     create :rating_rate, author: user_2, resource: article_1, value: 1
+
+    create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1
+    create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2
   end
 
   context 'with default filters' do
@@ -36,6 +41,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           article_1
         ]
       end
+
+      context 'with scope' do
+        it 'works' do
+          expect(Article.order_by_rating(:average, :asc, scope: category)).to eq [
+            article_1
+          ]
+        end
+      end
     end
 
     context 'as desc' do
@@ -46,6 +59,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           article_3
         ]
       end
+
+      context 'with scope' do
+        it 'works' do
+          expect(Article.order_by_rating(:average, :desc, scope: category)).to eq [
+            article_1
+          ]
+        end
+      end
     end
   end
 
@@ -58,6 +79,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           article_1
         ]
       end
+
+      context 'with scope' do
+        it 'works' do
+          expect(Article.order_by_rating(:estimate, :asc, scope: category)).to eq [
+            article_1
+          ]
+        end
+      end
     end
 
     context 'as desc' do
@@ -68,6 +97,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           article_3
         ]
       end
+
+      context 'with scope' do
+        it 'works' do
+          expect(Article.order_by_rating(:estimate, :desc, scope: category)).to eq [
+            article_1
+          ]
+        end
+      end
     end
   end
 
@@ -80,6 +117,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           article_1
         ]
       end
+
+      context 'with scope' do
+        it 'works' do
+          expect(Article.order_by_rating(:sum, :asc, scope: category)).to eq [
+            article_1
+          ]
+        end
+      end
     end
 
     context 'as desc' do
@@ -90,6 +135,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           article_3
         ]
       end
+
+      context 'with scope' do
+        it 'works' do
+          expect(Article.order_by_rating(:sum, :desc, scope: category)).to eq [
+            article_1
+          ]
+        end
+      end
     end
 
     context 'filtering by :total' do
@@ -100,6 +153,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           expect(result[0..1]).to match_array [article_2, article_3]
           expect(result.last).to  eq article_1
         end
+
+        context 'with scope' do
+          it 'works' do
+            expect(Article.order_by_rating(:total, :asc, scope: category)).to eq [
+              article_1
+            ]
+          end
+        end
       end
 
       context 'as desc' do
@@ -109,6 +170,14 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
           expect(result.first).to eq article_1
           expect(result[1..2]).to match_array [article_2, article_3]
         end
+
+        context 'with scope' do
+          it 'works' do
+            expect(Article.order_by_rating(:total, :desc, scope: category)).to eq [
+              article_1
+            ]
+          end
+        end
       end
     end
   end
@@ -117,5 +186,11 @@ RSpec.describe Rating::Extension, ':order_by_rating' do
     it 'works' do
       expect(User.order_by_rating(:total, :desc)).to match_array [user_1, user_2]
     end
+
+    context 'with scope' do
+      it 'returns empty since creation has no scope' do
+        expect(User.order_by_rating(:total, :desc, scope: category)).to eq []
+      end
+    end
   end
 end

spec/models/extension/rate_for_spec.rb

@@ -6,9 +6,21 @@ RSpec.describe Rating::Extension, ':rate_for' do
   let!(:user)    { create :user }
   let!(:article) { create :article }
 
+  context 'with no scopeable' do
     it 'delegates to rate object' do
-    expect(Rating::Rate).to receive(:rate_for).with author: user, resource: article
+      expect(Rating::Rate).to receive(:rate_for).with author: user, resource: article, scopeable: nil
 
       user.rate_for article
     end
+  end
+
+  context 'with scopeable' do
+    let!(:category) { build :category }
+
+    it 'delegates to rate object' do
+      expect(Rating::Rate).to receive(:rate_for).with author: user, resource: article, scopeable: category
+
+      user.rate_for article, scope: category
+    end
+  end
 end

spec/models/extension/rate_spec.rb

@@ -6,9 +6,21 @@ RSpec.describe Rating::Extension, ':rate' do
   let!(:user)    { create :user }
   let!(:article) { create :article }
 
+  context 'with no scopeable' do
     it 'delegates to rate object' do
-    expect(Rating::Rate).to receive(:create).with author: user, resource: article, value: 3
+      expect(Rating::Rate).to receive(:create).with author: user, resource: article, scopeable: nil, value: 3
 
       user.rate article, 3
     end
+  end
+
+  context 'with scopeable' do
+    let!(:category) { build :category }
+
+    it 'delegates to rate object' do
+      expect(Rating::Rate).to receive(:create).with author: user, resource: article, scopeable: category, value: 3
+
+      user.rate article, 3, scope: category
+    end
+  end
 end

spec/models/extension/rated_question_spec.rb

@@ -6,15 +6,33 @@ RSpec.describe Rating::Extension, ':rated?' do
   let!(:user)    { create :user }
   let!(:article) { create :article }
 
+  context 'with no scopeable' do
     context 'when has no rate for the given resource' do
-    before { allow(user).to receive(:rate_for).with(article) { nil } }
+      before { allow(user).to receive(:rate_for).with(article, scope: nil) { nil } }
 
       specify { expect(user.rated?(article)).to eq false }
     end
 
     context 'when has rate for the given resource' do
-    before { allow(user).to receive(:rate_for).with(article) { double } }
+      before { allow(user).to receive(:rate_for).with(article, scope: nil) { double } }
 
       specify { expect(user.rated?(article)).to eq true }
     end
+  end
+
+  context 'with scopeable' do
+    let!(:category) { build :category }
+
+    context 'when has no rate for the given resource' do
+      before { allow(user).to receive(:rate_for).with(article, scope: category) { nil } }
+
+      specify { expect(user.rated?(article, scope: category)).to eq false }
+    end
+
+    context 'when has rate for the given resource' do
+      before { allow(user).to receive(:rate_for).with(article, scope: category) { double } }
+
+      specify { expect(user.rated?(article, scope: category)).to eq true }
+    end
+  end
 end

spec/models/extension/rated_records_spec.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Rating::Extension, '.rated_records' do
+  let!(:category) { create :category }
+
+  let!(:user_1) { create :user }
+  let!(:user_2) { create :user }
+
+  let!(:article_1) { create :article }
+  let!(:article_2) { create :article }
+  let!(:article_3) { create :article }
+
+  let!(:rate_1) { create :rating_rate, author: user_1, resource: article_1, value: 100 }
+  let!(:rate_2) { create :rating_rate, author: user_1, resource: article_2, value: 11 }
+  let!(:rate_3) { create :rating_rate, author: user_1, resource: article_3, value: 10 }
+  let!(:rate_4) { create :rating_rate, author: user_2, resource: article_1, value: 1 }
+
+  let!(:rate_5) { create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1 }
+  let!(:rate_6) { create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2 }
+
+  it 'returns all rates that this author gave' do
+    expect(user_1.rated_records).to match_array [rate_1, rate_2, rate_3, rate_5]
+  end
+end

spec/models/extension/rated_spec.rb

@@ -3,36 +3,56 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Extension, ':rated' do
-  let!(:user)    { create :user }
+  let!(:category) { create :category }
-  let!(:article) { create :article }
 
-  before { user.rate article, 3 }
+  let!(:user_1) { create :user }
+  let!(:user_2) { create :user }
 
-  it 'returns rates made by the caller' do
+  let!(:article_1) { create :article }
-    expect(user.rated).to eq [Rating::Rate.find_by(resource: article)]
+  let!(:article_2) { create :article }
+  let!(:article_3) { create :article }
+
+  let!(:rate_1) { create :rating_rate, author: user_1, resource: article_1, value: 100 }
+  let!(:rate_2) { create :rating_rate, author: user_1, resource: article_2, value: 11 }
+  let!(:rate_3) { create :rating_rate, author: user_1, resource: article_3, value: 10 }
+  let!(:rate_4) { create :rating_rate, author: user_2, resource: article_1, value: 1 }
+
+  let!(:rate_5) { create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1 }
+  let!(:rate_6) { create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2 }
+
+  context 'with no scope' do
+    it 'returns rates made by this author' do
+      expect(user_1.rated).to match_array [rate_1, rate_2, rate_3]
+    end
+  end
+
+  context 'with no scope' do
+    it 'returns scoped rates made by this author' do
+      expect(user_1.rated(scope: category)).to eq [rate_5]
+    end
   end
 
   context 'when destroy author' do
     before do
-      expect(Rating::Rate.where(author: user).count).to eq 1
+      expect(Rating::Rate.where(author: user_1).count).to eq 4
 
-      user.destroy!
+      user_1.destroy!
     end
 
-    it 'destroys rates of this author' do
+    it 'destroys rates of that author' do
-      expect(Rating::Rate.where(author: user).count).to eq 0
+      expect(Rating::Rate.where(author: user_1).count).to eq 0
     end
   end
 
   context 'when destroy resource rated by author' do
     before do
-      expect(Rating::Rate.where(resource: article).count).to eq 1
+      expect(Rating::Rate.where(resource: article_1).count).to eq 4
 
-      article.destroy!
+      article_1.destroy!
     end
 
-    it 'destroys rates for that resource' do
+    it 'destroys rates of that resource' do
-      expect(Rating::Rate.where(resource: article).count).to eq 0
+      expect(Rating::Rate.where(resource: article_1).count).to eq 0
     end
   end
 end

spec/models/extension/rates_records_spec.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Rating::Extension, '.rates_records' do
+  let!(:category) { create :category }
+
+  let!(:user_1) { create :user }
+  let!(:user_2) { create :user }
+
+  let!(:article_1) { create :article }
+  let!(:article_2) { create :article }
+  let!(:article_3) { create :article }
+
+  let!(:rate_1) { create :rating_rate, author: user_1, resource: article_1, value: 100 }
+  let!(:rate_2) { create :rating_rate, author: user_1, resource: article_2, value: 11 }
+  let!(:rate_3) { create :rating_rate, author: user_1, resource: article_3, value: 10 }
+  let!(:rate_4) { create :rating_rate, author: user_2, resource: article_1, value: 1 }
+
+  let!(:rate_5) { create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1 }
+  let!(:rate_6) { create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2 }
+
+  it 'returns all rates that this resource received' do
+    expect(article_1.rates_records).to match_array [rate_1, rate_4, rate_5, rate_6]
+  end
+end

spec/models/extension/rates_spec.rb

@@ -3,36 +3,52 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Extension, ':rates' do
-  let!(:user)    { create :user }
+  let!(:category) { create :category }
-  let!(:article) { create :article }
 
-  before { user.rate article, 3 }
+  let!(:user_1) { create :user }
+  let!(:user_2) { create :user }
 
-  it 'returns rates record' do
+  let!(:article_1) { create :article }
-    expect(article.rates).to eq [Rating::Rate.last]
+  let!(:article_2) { create :article }
+  let!(:article_3) { create :article }
+
+  let!(:rate_1) { create :rating_rate, author: user_1, resource: article_1, value: 100 }
+  let!(:rate_2) { create :rating_rate, author: user_1, resource: article_2, value: 11 }
+  let!(:rate_3) { create :rating_rate, author: user_1, resource: article_3, value: 10 }
+  let!(:rate_4) { create :rating_rate, author: user_2, resource: article_1, value: 1 }
+
+  let!(:rate_5) { create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1 }
+  let!(:rate_6) { create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2 }
+
+  context 'with no scope' do
+    it 'returns rates that this resource received' do
+      expect(article_1.rates).to match_array [rate_1, rate_4]
+    end
+  end
+
+  context 'with scope' do
+    it 'returns scoped rates that this resource received' do
+      expect(article_1.rates(scope: category)).to match_array [rate_5, rate_6]
+    end
   end
 
   context 'when destroy author' do
-    before do
+    it 'destroys rates of that author' do
-      expect(Rating::Rate.where(resource: article).count).to eq 1
+      expect(Rating::Rate.where(author: user_1).count).to eq 4
 
-      user.destroy!
+      user_1.destroy!
-    end
 
-    it 'destroys rates of that resource' do
+      expect(Rating::Rate.where(author: user_1).count).to eq 0
-      expect(Rating::Rate.where(resource: article).count).to eq 0
     end
   end
 
   context 'when destroy resource' do
-    before do
-      expect(Rating::Rate.where(resource: article).count).to eq 1
-
-      article.destroy!
-    end
-
     it 'destroys rates of that resource' do
-      expect(Rating::Rate.where(resource: article).count).to eq 0
+      expect(Rating::Rate.where(resource: article_1).count).to eq 4
+
+      article_1.destroy!
+
+      expect(Rating::Rate.where(resource: article_1).count).to eq 0
     end
   end
 end

spec/models/extension/rating_records_spec.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Rating::Extension, '.rating' do
+  let!(:category) { create :category }
+
+  let!(:user_1) { create :user }
+  let!(:user_2) { create :user }
+
+  let!(:article_1) { create :article }
+  let!(:article_2) { create :article }
+  let!(:article_3) { create :article }
+
+  before do
+    create :rating_rate, author: user_1, resource: article_1, value: 100
+    create :rating_rate, author: user_1, resource: article_2, value: 11
+    create :rating_rate, author: user_1, resource: article_3, value: 10
+    create :rating_rate, author: user_2, resource: article_1, value: 1
+
+    create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1
+    create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2
+  end
+
+  it 'returns all rating of this resource' do
+    expect(article_1.rating_records).to match_array Rating::Rating.where(resource: article_1)
+  end
+end

spec/models/extension/rating_spec.rb

@@ -2,37 +2,53 @@
 
 require 'rails_helper'
 
-RSpec.describe Rating::Extension, ':rating' do
+RSpec.describe Rating::Extension, '.rating' do
+  let!(:category) { create :category }
+
   let!(:user_1) { create :user }
-  let!(:article) { create :article }
+  let!(:user_2) { create :user }
 
-  before { user_1.rate article, 1 }
+  let!(:article_1) { create :article }
+  let!(:article_2) { create :article }
+  let!(:article_3) { create :article }
 
+  let!(:rate_1) { create :rating_rate, author: user_1, resource: article_1, value: 100 }
+  let!(:rate_2) { create :rating_rate, author: user_1, resource: article_2, value: 11 }
+  let!(:rate_3) { create :rating_rate, author: user_1, resource: article_3, value: 10 }
+  let!(:rate_4) { create :rating_rate, author: user_2, resource: article_1, value: 1 }
+
+  let!(:rate_5) { create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1 }
+  let!(:rate_6) { create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2 }
+
+  context 'with no scope' do
     it 'returns rating record' do
-    expect(article.rating).to eq Rating::Rating.last
+      expect(article_1.rating).to eq Rating::Rating.find_by(resource: article_1, scopeable: nil)
+    end
+  end
+
+  context 'with scope' do
+    it 'returns scoped rating record' do
+      expect(article_1.rating(scope: category)).to eq Rating::Rating.find_by(resource: article_1, scopeable: category)
+    end
   end
 
   context 'when destroy author' do
-    let!(:user_2) { create :user }
-
-    before { user_2.rate article, 2 }
-
     it 'does not destroy resource rating' do
-      expect(Rating::Rating.where(resource: article).count).to eq 1
+      expect(Rating::Rating.where(resource: article_1).count).to eq 2
 
       user_1.destroy!
 
-      expect(Rating::Rating.where(resource: article).count).to eq 1
+      expect(Rating::Rating.where(resource: article_1).count).to eq 2
     end
   end
 
   context 'when destroy resource' do
     it 'destroys resource rating too' do
-      expect(Rating::Rating.where(resource: article).count).to eq 1
+      expect(Rating::Rating.where(resource: article_1).count).to eq 2
 
-      article.destroy!
+      article_1.destroy!
 
-      expect(Rating::Rating.where(resource: article).count).to eq 0
+      expect(Rating::Rating.where(resource: article_1).count).to eq 0
     end
   end
 end

spec/models/rate/create_spec.rb

@@ -6,6 +6,7 @@ RSpec.describe Rating::Rate, ':create' do
   let!(:user)    { create :user }
   let!(:article) { create :article }
 
+  context 'with no scopeable' do
     before { create :rating_rate, author: user, resource: article, value: 3 }
 
     context 'when rate does not exist yet' do
@@ -61,4 +62,70 @@ RSpec.describe Rating::Rate, ':create' do
         expect(rating.total).to    eq 2
       end
     end
+  end
+
+  context 'with scopeable' do
+    let!(:category) { create :category }
+
+    before { create :rating_rate, author: user, resource: article, scopeable: category, value: 3 }
+
+    context 'when rate does not exist yet' do
+      it 'creates a rate entry' do
+        rate = described_class.last
+
+        expect(rate.author).to    eq user
+        expect(rate.resource).to  eq article
+        expect(rate.scopeable).to eq category
+        expect(rate.value).to     eq 3
+      end
+
+      it 'creates a rating entry' do
+        rating = Rating::Rating.last
+
+        expect(rating.average).to   eq 3
+        expect(rating.estimate).to  eq 3
+        expect(rating.resource).to  eq article
+        expect(rating.scopeable).to eq category
+        expect(rating.sum).to       eq 3
+        expect(rating.total).to     eq 1
+      end
+    end
+
+    context 'when rate already exists' do
+      let!(:user_2) { create :user }
+
+      before { create :rating_rate, author: user_2, resource: article, scopeable: category, value: 4 }
+
+      it 'creates one more rate entry' do
+        rates = described_class.where(author: [user, user_2]).order('created_at asc')
+
+        expect(rates.size).to eq 2
+
+        rate = rates[0]
+
+        expect(rate.author).to    eq user
+        expect(rate.resource).to  eq article
+        expect(rate.scopeable).to eq category
+        expect(rate.value).to     eq 3
+
+        rate = rates[1]
+
+        expect(rate.author).to    eq user_2
+        expect(rate.resource).to  eq article
+        expect(rate.scopeable).to eq category
+        expect(rate.value).to     eq 4
+      end
+
+      it 'updates the unique rating entry' do
+        rating = Rating::Rating.find_by(resource: article, scopeable: category)
+
+        expect(rating.average).to   eq 3.5
+        expect(rating.estimate).to  eq 3.5
+        expect(rating.resource).to  eq article
+        expect(rating.scopeable).to eq category
+        expect(rating.sum).to       eq 7
+        expect(rating.total).to     eq 2
+      end
+    end
+  end
 end

spec/models/rate/rate_for_spec.rb

@@ -6,6 +6,7 @@ RSpec.describe Rating::Rate, ':rate_for' do
   let!(:user)    { create :user }
   let!(:article) { create :article }
 
+  context 'with no scopeable' do
     context 'when rate does not exist' do
       specify { expect(described_class.rate_for(author: user, resource: article)).to eq nil }
     end
@@ -17,4 +18,23 @@ RSpec.describe Rating::Rate, ':rate_for' do
         expect(described_class.rate_for(author: user, resource: article)).to eq described_class.last
       end
     end
+  end
+
+  context 'with scopeable' do
+    let!(:category) { create :category }
+
+    context 'when rate does not exist' do
+      specify { expect(described_class.rate_for(author: user, resource: article, scopeable: category)).to eq nil }
+    end
+
+    context 'when rate does not exist' do
+      before { described_class.create author: user, resource: article, scopeable: category, value: 3 }
+
+      it 'returns the record' do
+        query = described_class.rate_for(author: user, resource: article, scopeable: category)
+
+        expect(query).to eq described_class.last
+      end
+    end
+  end
 end

spec/models/rate_spec.rb

@@ -9,6 +9,7 @@ RSpec.describe Rating::Rate do
 
   it { is_expected.to belong_to :author }
   it { is_expected.to belong_to :resource }
+  it { is_expected.to belong_to :scopeable }
 
   it { is_expected.to validate_presence_of :author }
   it { is_expected.to validate_presence_of :resource }
@@ -20,7 +21,7 @@ RSpec.describe Rating::Rate do
 
   specify do
     expect(object).to validate_uniqueness_of(:author_id)
-      .scoped_to(%i[author_type resource_id resource_type])
+      .scoped_to(%i[author_type resource_id resource_type scopeable_id scopeable_type])
       .case_insensitive
   end
 end

spec/models/rating/averager_data_spec.rb

@@ -3,7 +3,7 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Rating, ':averager_data' do
-  subject { described_class.averager_data article_1 }
+  let!(:category) { create :category }
 
   let!(:user_1) { create :user }
   let!(:user_2) { create :user }
@@ -17,8 +17,14 @@ RSpec.describe Rating::Rating, ':averager_data' do
     create :rating_rate, author: user_1, resource: article_2, value: 11
     create :rating_rate, author: user_1, resource: article_3, value: 10
     create :rating_rate, author: user_2, resource: article_1, value: 1
+
+    create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1
+    create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2
   end
 
+  context 'with no scopeable' do
+    subject { described_class.averager_data article_1, nil }
+
     it 'returns the values average of given resource type' do
       expect(subject.as_json['rating_avg']).to eq 30.5
     end
@@ -26,4 +32,17 @@ RSpec.describe Rating::Rating, ':averager_data' do
     it 'returns the average of number of records for the given resource type' do
       expect(subject.as_json['count_avg']).to eq 1.3333333333333333
     end
+  end
+
+  context 'with scopeable' do
+    subject { described_class.averager_data article_1, category }
+
+    it 'returns the values average of given resource type' do
+      expect(subject.as_json['rating_avg']).to eq 1.5
+    end
+
+    it 'returns the average of number of records for the given resource type' do
+      expect(subject.as_json['count_avg']).to eq 2
+    end
+  end
 end

spec/models/rating/data_spec.rb

@@ -3,7 +3,7 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Rating, ':data' do
-  subject { described_class.data article_1 }
+  let!(:category) { create :category }
 
   let!(:user_1) { create :user }
   let!(:user_2) { create :user }
@@ -17,8 +17,14 @@ RSpec.describe Rating::Rating, ':data' do
     create :rating_rate, author: user_1, resource: article_2, value: 11
     create :rating_rate, author: user_1, resource: article_3, value: 10
     create :rating_rate, author: user_2, resource: article_1, value: 1
+
+    create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1
+    create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2
   end
 
+  context 'with no scopeable' do
+    subject { described_class.data article_1, nil }
+
     it 'returns the average of value for a resource' do
       expect(subject[:average]).to eq 50.5
     end
@@ -34,4 +40,25 @@ RSpec.describe Rating::Rating, ':data' do
     it 'returns the estimate for a resource' do
       expect(subject[:estimate]).to eq 42.50000000000001
     end
+  end
+
+  context 'with scopeable' do
+    subject { described_class.data article_1, category }
+
+    it 'returns the average of value for a resource' do
+      expect(subject[:average]).to eq 1.5
+    end
+
+    it 'returns the sum of values for a resource' do
+      expect(subject[:sum]).to eq 3
+    end
+
+    it 'returns the count of votes for a resource' do
+      expect(subject[:total]).to eq 2
+    end
+
+    it 'returns the estimate for a resource' do
+      expect(subject[:estimate]).to eq 1.5
+    end
+  end
 end

spec/models/rating/update_rating_spec.rb

@@ -3,6 +3,8 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Rating, ':update_rating' do
+  let!(:category) { create :category }
+
   let!(:user_1) { create :user }
   let!(:user_2) { create :user }
 
@@ -15,8 +17,12 @@ RSpec.describe Rating::Rating, ':update_rating' do
     create :rating_rate, author: user_1, resource: article_2, value: 11
     create :rating_rate, author: user_1, resource: article_3, value: 10
     create :rating_rate, author: user_2, resource: article_1, value: 1
+
+    create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1
+    create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2
   end
 
+  context 'with no scopeable' do
     it 'updates the rating data of the given resource' do
       record = described_class.find_by(resource: article_1)
 
@@ -25,4 +31,16 @@ RSpec.describe Rating::Rating, ':update_rating' do
       expect(record.sum).to      eq 101
       expect(record.total).to    eq 2
     end
+  end
+
+  context 'with scopeable' do
+    it 'updates the rating data of the given resource respecting the scope' do
+      record = described_class.find_by(resource: article_1, scopeable: category)
+
+      expect(record.average).to  eq 1.5
+      expect(record.estimate).to eq 1.5
+      expect(record.sum).to      eq 3
+      expect(record.total).to    eq 2
+    end
+  end
 end

spec/models/rating/values_data_spec.rb

@@ -3,7 +3,7 @@
 require 'rails_helper'
 
 RSpec.describe Rating::Rating, ':values_data' do
-  subject { described_class.values_data article_1 }
+  let!(:category) { create :category }
 
   let!(:user_1) { create :user }
   let!(:user_2) { create :user }
@@ -17,8 +17,14 @@ RSpec.describe Rating::Rating, ':values_data' do
     create :rating_rate, author: user_1, resource: article_2, value: 11
     create :rating_rate, author: user_1, resource: article_3, value: 10
     create :rating_rate, author: user_2, resource: article_1, value: 4
+
+    create :rating_rate, author: user_1, resource: article_1, scopeable: category, value: 1
+    create :rating_rate, author: user_2, resource: article_1, scopeable: category, value: 2
   end
 
+  context 'with no scopeable' do
+    subject { described_class.values_data article_1, nil }
+
     it 'returns the average of value for a resource' do
       expect(subject.as_json['rating_avg']).to eq 52.0
     end
@@ -30,4 +36,21 @@ RSpec.describe Rating::Rating, ':values_data' do
     it 'returns the count of votes for a resource' do
       expect(subject.as_json['rating_count']).to eq 2
     end
+  end
+
+  context 'with scopeable' do
+    subject { described_class.values_data article_1, category }
+
+    it 'returns the average of value for a resource' do
+      expect(subject.as_json['rating_avg']).to eq 1.5
+    end
+
+    it 'returns the sum of values for a resource' do
+      expect(subject.as_json['rating_sum']).to eq 3
+    end
+
+    it 'returns the count of votes for a resource' do
+      expect(subject.as_json['rating_count']).to eq 2
+    end
+  end
 end

spec/models/rating_spec.rb

@@ -8,6 +8,7 @@ RSpec.describe Rating::Rating do
   it { expect(object).to be_valid }
 
   it { is_expected.to belong_to :resource }
+  it { is_expected.to belong_to :scopeable }
 
   it { is_expected.to validate_presence_of :average }
   it { is_expected.to validate_presence_of :estimate }

spec/support/db/migrate/create_category_spec.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class CreateCategoriesTable < ActiveRecord::Migration[5.0]
+  def change
+    create_table :categories do |t|
+      t.string :name, null: false
+    end
+  end
+end

spec/support/migrate.rb

@@ -2,6 +2,7 @@
 
 require File.expand_path('../../lib/generators/rating/templates/db/migrate/create_rating_tables.rb', __dir__)
 
+CreateArticlesTable.new.change
+CreateCategoriesTable.new.change
 CreateRatingTables.new.change
 CreateUsersTable.new.change
-CreateArticlesTable.new.change

spec/support/models/category.rb

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+class Category < ::ActiveRecord::Base
+end