Use exec_query wrapper for ProjectAuthorization.roles_stats

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

ee/app/models/ee/project_authorization.rb

@@ -3,8 +3,20 @@ module EE
     extend ActiveSupport::Concern
 
     module ClassMethods
+      # Get amout of users with highest role they have.
+      # If John is developer in one project but master in another he will be
+      # counted once as master. This is needed to count users who don't use
+      # functionality available to higher roles only.
+      #
+      # Example of result:
+      #  [{"kind"=>"guest", "amount"=>"4"},
+      #  {"kind"=>"reporter", "amount"=>"6"},
+      #  {"kind"=>"developer", "amount"=>"10"},
+      #  {"kind"=>"master", "amount"=>"9"},
+      #  {"kind"=>"owner", "amount"=>"1"}]
+      #
       def roles_stats
-        connection.execute <<-EOF.strip_heredoc
+        connection.exec_query <<-EOF.strip_heredoc
           SELECT CASE access_level
             WHEN 10 THEN 'guest'
             WHEN 20 THEN 'reporter'

ee/spec/models/ee/project_authorization_spec.rb

@@ -19,9 +19,15 @@ describe ProjectAuthorization do
     subject { described_class.roles_stats.to_a }
 
     it do
-      expect(subject).to include({ 'kind' => 'reporter', 'amount' => '1' })
-      expect(subject).to include({ 'kind' => 'developer', 'amount' => '2' })
-      expect(subject).to include({ 'kind' => 'master', 'amount' => '2' })
+      expect(amount_for_kind('reporter')).to eq(1)
+      expect(amount_for_kind('developer')).to eq(2)
+      expect(amount_for_kind('master')).to eq(2)
+    end
+
+    def amount_for_kind(access_level)
+      subject.find do |row|
+        row['kind'] == access_level
+      end['amount'].to_i
     end
   end
 end