feat: add ability to persist metadata

lib/rating/models/rating/rate.rb

@@ -23,6 +23,8 @@ module Rating
 
       return record if record.persisted? && value == record.value
 
+      metadata.each { |k, v| record[k] = v } if metadata.present?
+
       record.value = value
       record.save
 

spec/models/rate/create_spec.rb

@@ -128,4 +128,47 @@ RSpec.describe Rating::Rate, ':create' do
       end
     end
   end
+
+  context 'with metadata' do
+    before { AddCommentOnRatingRatesTable.new.change }
+
+    context 'with nil value' do
+      it 'creates a rate entry ignoring metadata' do
+        described_class.create author: author, metadata: nil, resource: article, value: 3
+
+        rate = described_class.last
+
+        expect(rate.author).to   eq author
+        expect(rate.comment).to  eq nil
+        expect(rate.resource).to eq article
+        expect(rate.value).to    eq 3
+      end
+    end
+
+    context 'with empty value' do
+      it 'creates a rate entry ignoring metadata' do
+        described_class.create author: author, metadata: '', resource: article, value: 3
+
+        rate = described_class.last
+
+        expect(rate.author).to   eq author
+        expect(rate.comment).to  eq nil
+        expect(rate.resource).to eq article
+        expect(rate.value).to    eq 3
+      end
+    end
+
+    context 'with hash value' do
+      it 'creates a rate entry with metadata included' do
+        described_class.create author: author, metadata: { comment: 'comment' }, resource: article, value: 3
+
+        rate = described_class.last
+
+        expect(rate.author).to   eq author
+        expect(rate.comment).to  eq 'comment'
+        expect(rate.resource).to eq article
+        expect(rate.value).to    eq 3
+      end
+    end
+  end
 end

spec/support/db/migrate/add_comment_on_rating_rates_table.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddCommentOnRatingRatesTable < ActiveRecord::Migration[5.0]
+  def change
+    add_column :rating_rates, :comment, :text
+  end
+end