Set some stricter Rubocop rules

.rubocop.yml

@@ -1,23 +1,43 @@
+require: 
+  - rt_rubocop_defaults
+  - rubocop-rails
 AllCops:
-  NewCops: enable
+  TargetRubyVersion: 2.5
   Exclude:
+    - 'config/**/*'
     - 'vendor/**/*'
     - 'db/schema.rb'
+    - 'db/seeds.rb'
+    - 'bin/**/*'
+    - 'node_modules/**/*'
 
-Metrics/ClassLength:
+Rails:
+  Enabled: true
+
+Rails/InverseOf:
   Enabled: false
 
+Metrics/AbcSize:
+  Max: 20
+  Exclude:
+    - 'db/**/*'
+
 Layout/LineLength:
   Enabled: false
 
 Metrics/MethodLength:
-  Enabled: false
-
-Metrics/ModuleLength:
-  Enabled: false
+  Max: 15
+  Exclude:
+    - 'db/migrate/*.rb'
 
 Style/ClassAndModuleChildren:
   Enabled: false
 
 Style/Documentation:
   Enabled: false
+
+Style/RescueStandardError:
+  Enabled: false
+
+Style/Encoding:
+  Enabled: false

Gemfile

@@ -94,6 +94,8 @@ group :development, :test do
   gem 'timecop'
   gem 'rails-controller-testing'
   gem 'haml_lint', require: false
+  gem 'rubocop-rails', '~> 2.13', '>= 2.13.1'
+  gem 'rt_rubocop_defaults', '~> 2.3', '>= 2.3.1'
 end
 
 gem "webpacker", "~> 5.2"

Gemfile.lock

@@ -474,6 +474,8 @@ GEM
       rspec-core (~> 3.0, >= 3.0.0)
       sidekiq (>= 2.4.0)
     rspec-support (3.10.3)
+    rt_rubocop_defaults (2.3.1)
+      rubocop (~> 1.5)
     rubocop (1.24.1)
       parallel (~> 1.10)
       parser (>= 3.0.0.0)
@@ -485,6 +487,10 @@ GEM
       unicode-display_width (>= 1.4.0, < 3.0)
     rubocop-ast (1.15.1)
       parser (>= 3.0.1.1)
+    rubocop-rails (2.13.1)
+      activesupport (>= 4.2.0)
+      rack (>= 1.1)
+      rubocop (>= 1.7.0, < 2.0)
     ruby-progressbar (1.11.0)
     ruby-vips (2.1.4)
       ffi (~> 1.12)
@@ -658,6 +664,8 @@ DEPENDENCIES
   rspec-mocks
   rspec-rails (~> 4.0)
   rspec-sidekiq (~> 3.0)
+  rt_rubocop_defaults (~> 2.3, >= 2.3.1)
+  rubocop-rails (~> 2.13, >= 2.13.1)
   ruby-progressbar
   sanitize
   sass-rails (~> 5.0)