fix: float does not exists on mysql

fix precision on average calculation making dividend as decimal

Gemfile.lock

@@ -54,6 +54,7 @@ GEM
     method_source (0.9.0)
     mini_portile2 (2.3.0)
     minitest (5.11.3)
+    mysql2 (0.4.10)
     nokogiri (1.8.2)
       mini_portile2 (~> 2.3.0)
     parallel (1.12.1)
@@ -66,7 +67,7 @@ GEM
     pry-byebug (3.5.1)
       byebug (~> 9.1)
       pry (~> 0.10)
-    rack (2.0.3)
+    rack (2.0.4)
     rack-test (0.8.2)
       rack (>= 1.0, < 3)
     rails-dom-testing (2.0.3)
@@ -98,7 +99,7 @@ GEM
       rspec-expectations (~> 3.7.0)
       rspec-mocks (~> 3.7.0)
       rspec-support (~> 3.7.0)
-    rspec-support (3.7.0)
+    rspec-support (3.7.1)
     rubocop (0.52.1)
       parallel (~> 1.10)
       parser (>= 2.4.0.2, < 3.0)
@@ -106,15 +107,14 @@ GEM
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
-    rubocop-rspec (1.22.1)
+    rubocop-rspec (1.22.2)
       rubocop (>= 0.52.1)
     ruby-progressbar (1.9.0)
     shoulda-matchers (3.1.2)
       activesupport (>= 4.0.0)
-    sqlite3 (1.3.13)
     thor (0.20.0)
     thread_safe (0.3.6)
-    tzinfo (1.2.4)
+    tzinfo (1.2.5)
       thread_safe (~> 0.1)
     unicode-display_width (1.3.0)
 
@@ -124,12 +124,12 @@ PLATFORMS
 DEPENDENCIES
   database_cleaner
   factory_bot_rails
+  mysql2
   pry-byebug
   rating!
   rspec-rails
   rubocop-rspec
   shoulda-matchers
-  sqlite3
 
 BUNDLED WITH
    1.16.1

lib/rating/models/rating/rating.rb

@@ -25,8 +25,8 @@ module Rating
 
         sql = %(
           SELECT
-            (#{total_count} / CAST(#{distinct_count} AS float)) count_avg,
-            COALESCE(AVG(value), 0)                             rating_avg
+            (CAST(#{total_count} AS DECIMAL(17, 14)) / #{distinct_count}) count_avg,
+            COALESCE(AVG(value), 0)                                       rating_avg
           FROM #{rate_table_name}
           WHERE resource_type = :resource_type AND #{scope_type_query(scopeable)}
         ).squish

rating.gemspec

@@ -23,9 +23,9 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency 'database_cleaner'
   spec.add_development_dependency 'factory_bot_rails'
+  spec.add_development_dependency 'mysql2'
   spec.add_development_dependency 'pry-byebug'
   spec.add_development_dependency 'rspec-rails'
   spec.add_development_dependency 'rubocop-rspec'
   spec.add_development_dependency 'shoulda-matchers'
-  spec.add_development_dependency 'sqlite3'
 end

spec/models/rating/averager_data_spec.rb

@@ -14,7 +14,7 @@ RSpec.describe Rating::Rating, ':averager_data' do
     end
 
     it 'returns the average of number of records for the given resource type' do
-      expect(result.as_json['count_avg']).to eq 1.3333333333333333
+      expect(result.as_json['count_avg'].to_s).to eq '1.333333333333333333'
     end
   end
 

spec/models/rating/data_spec.rb

@@ -22,7 +22,7 @@ RSpec.describe Rating::Rating, ':data' do
     end
 
     it 'returns the estimate for a resource' do
-      expect(result[:estimate]).to eq 42.50000000000001
+      expect(result[:estimate].to_s).to eq '42.5000000000000000012000000505'
     end
   end
 

spec/models/rating/update_rating_spec.rb

@@ -10,8 +10,8 @@ RSpec.describe Rating::Rating, ':update_rating' do
     it 'updates the rating data of the given resource' do
       record = described_class.find_by(resource: article_1)
 
-      expect(record.average).to  eq 50.50000000000001
-      expect(record.estimate).to eq 42.50000000000001
+      expect(record.average).to  eq 50.5
+      expect(record.estimate).to eq 42.5
       expect(record.sum).to      eq 101
       expect(record.total).to    eq 2
     end

spec/rails_helper.rb

@@ -3,9 +3,15 @@
 ENV['RAILS_ENV'] ||= 'test'
 
 require 'active_record/railtie'
+require 'mysql2'
 require 'pry-byebug'
 require 'rating'
 
-ActiveRecord::Base.establish_connection adapter: :sqlite3, database: ':memory:'
+client = Mysql2::Client.new(host: :localhost, username: :root)
+
+client.query 'DROP DATABASE rating_test;'
+client.query 'CREATE DATABASE rating_test;'
+
+ActiveRecord::Base.establish_connection adapter: :mysql2, database: :rating_test, username: :root
 
 Dir[File.expand_path('support/**/*.rb', __dir__)].each { |file| require file }