Add rubocop configuration

.rubocop.yml

@@ -0,0 +1,35 @@
+---
+AllCops:
+  # Matches the minimum version in .travis.yml
+  TargetRubyVersion: 2.4
+
+Style/StringLiterals:
+  EnforcedStyle: "double_quotes"
+
+# New cops: https://docs.rubocop.org/en/latest/versioning/
+Layout/EmptyLinesAroundAttributeAccessor:
+  Enabled: true
+
+Layout/SpaceAroundMethodCallOperator:
+  Enabled: true
+
+Lint/RaiseException:
+  Enabled: true
+
+Lint/StructNewOverride:
+  Enabled: true
+
+Style/ExponentialNotation:
+  Enabled: true
+
+Style/HashEachMethods:
+  Enabled: true
+
+Style/HashTransformKeys:
+  Enabled: true
+
+Style/HashTransformValues:
+  Enabled: true
+
+Style/SlicingWithRange:
+  Enabled: true

.travis.yml

@@ -7,14 +7,16 @@ rvm:
   - ruby-head
 
 gemfile:
- - Gemfile
+  - Gemfile
 
 branches:
   only:
     - master
 
 before_install: gem update bundler
-script: bundle exec rake test
+script:
+  - bundle exec rake test
+  - bundle exec rubocop
 
 sudo: false
 

fluent-plugin-gcloud-pubsub-custom.gemspec

@@ -20,6 +20,7 @@ Gem::Specification.new do |gem|
 
   gem.add_development_dependency "bundler"
   gem.add_development_dependency "rake"
+  gem.add_development_dependency "rubocop", "~>0.83"
   gem.add_development_dependency "test-unit"
   gem.add_development_dependency "test-unit-rr"
 end