Add flay: tool to find duplicate code

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

.flayignore

@@ -0,0 +1 @@
+*.erb

.gitlab-ci.yml

@@ -81,3 +81,11 @@ flog:
     - ruby
     - mysql
   allow_failure: true
+
+flay:
+  script:
+    - bundle exec rake flay
+  tags:
+    - ruby
+    - mysql
+  allow_failure: true

Gemfile

@@ -260,6 +260,7 @@ group :development, :test do
   gem 'coveralls',  '~> 0.8.2', require: false
   gem 'simplecov', '~> 0.10.0', require: false
   gem 'flog', require: false
+  gem 'flay', require: false
 
   gem 'benchmark-ips', require: false
 end

Gemfile.lock

@@ -194,6 +194,9 @@ GEM
     ffi (1.9.10)
     fission (0.5.0)
       CFPropertyList (~> 2.2)
+    flay (2.6.1)
+      ruby_parser (~> 3.0)
+      sexp_processor (~> 4.0)
     flog (4.3.2)
       ruby_parser (~> 3.1, > 3.1.0)
       sexp_processor (~> 4.4)
@@ -824,6 +827,7 @@ DEPENDENCIES
   enumerize (~> 0.7.0)
   factory_girl_rails (~> 4.3.0)
   ffaker (~> 2.0.0)
+  flay
   flog
   fog (~> 1.25.0)
   font-awesome-rails (~> 4.2)

lib/tasks/flay.rake

@@ -0,0 +1,9 @@
+desc 'Code duplication analyze via flay'
+task :flay do
+  output = %x(bundle exec flay app/ lib/gitlab/)
+
+  if output.include? "Similar code found"
+    puts output
+    exit 1
+  end
+end