Configure RuboCop

.rubocop.yml

@@ -0,0 +1,39 @@
+AllCops:
+  TargetRubyVersion: 2.5
+  DisplayCopNames: true
+
+  Exclude:
+    - 'bin/**/*'
+    - 'db/schema.rb'
+    - 'vendor/**/*'
+
+Layout/AccessModifierIndentation:
+  EnforcedStyle: outdent
+
+Layout/EmptyLinesAroundArguments:
+  Enabled: false
+
+Rails:
+  Enabled: true
+
+Style/AndOr:
+  EnforcedStyle: conditionals
+
+Style/ClassAndModuleChildren:
+  Exclude:
+    - 'app/**/*'
+
+Style/Documentation:
+  Enabled: false
+
+Style/DoubleNegation:
+  Enabled: false
+
+Style/TrailingCommaInArguments:
+  EnforcedStyleForMultiline: comma
+
+Style/TrailingCommaInArrayLiteral:
+  EnforcedStyleForMultiline: comma
+
+Style/TrailingCommaInHashLiteral:
+  EnforcedStyleForMultiline: comma

Gemfile

@@ -37,6 +37,10 @@ group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution
   # and get a debugger console.
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
+
+  # Automatic Ruby code style checking tool.
+  # Aims to enforce the community-driven Ruby Style Guide.
+  gem 'rubocop', '~> 0.60.0'
 end
 
 group :development do

Gemfile.lock

@@ -43,6 +43,7 @@ GEM
       minitest (~> 5.1)
       tzinfo (~> 1.1)
     arel (9.0.0)
+    ast (2.4.0)
     bindex (0.5.0)
     bootsnap (1.3.2)
       msgpack (~> 1.0)
@@ -58,6 +59,7 @@ GEM
       activesupport (>= 4.2.0)
     i18n (1.1.1)
       concurrent-ruby (~> 1.0)
+    jaro_winkler (1.5.1)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
@@ -78,7 +80,11 @@ GEM
     nio4r (2.3.1)
     nokogiri (1.8.5)
       mini_portile2 (~> 2.3.0)
+    parallel (1.12.1)
+    parser (2.5.3.0)
+      ast (~> 2.4.0)
     pg (1.1.3)
+    powerpack (0.1.2)
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
@@ -112,10 +118,20 @@ GEM
       method_source
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
+    rainbow (3.0.0)
     rake (12.3.1)
     rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
+    rubocop (0.60.0)
+      jaro_winkler (~> 1.5.1)
+      parallel (~> 1.10)
+      parser (>= 2.5, != 2.5.1.1)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.4.0)
+    ruby-progressbar (1.10.0)
     ruby_dep (1.5.0)
     sass (3.7.2)
       sass-listen (~> 4.0.0)
@@ -150,6 +166,7 @@ GEM
       thread_safe (~> 0.1)
     uglifier (4.1.20)
       execjs (>= 0.3.0, < 3)
+    unicode-display_width (1.4.0)
     web-console (3.7.0)
       actionview (>= 5.0)
       activemodel (>= 5.0)
@@ -170,6 +187,7 @@ DEPENDENCIES
   pry-rails (~> 0.3)
   puma (~> 3.11)
   rails (~> 5.2.1)
+  rubocop (~> 0.60.0)
   sass-rails (~> 5.0)
   spring
   spring-watcher-listen (~> 2.0.0)

Rakefile

@@ -1,6 +1,19 @@
-# Add your own tasks in files placed in lib/tasks ending in .rake,
-# for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
-
 require_relative 'config/application'
 
 Rails.application.load_tasks
+
+desc 'Run all checks (test, lint...)'
+task default: :lint
+
+desc 'Run all code analysis tools (RuboCop...)'
+task lint: :rubocop
+
+desc 'Fix code style (rubocop --auto-correct)'
+task fix: 'rubocop:auto_correct'
+
+begin
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new
+rescue LoadError
+  nil
+end