My personal rubocop config. Will add more soon

.rubocop.yml

Metrics/LineLength:
  Max: 120
AllCops:
  TargetRubyVersion: 2.2
# Too short methods lead to extraction of single-use methods, which can make
# the code easier to read (by naming things), but can also clutter the class
Metrics/MethodLength:
  Max: 20

Metrics/ClassLength:
  Max: 150

Style/HashSyntax:
  EnforcedStyle: ruby19_no_mixed_keys

Style/CollectionMethods:
  Enabled: true
  PreferredMethods:
    # inject seems more common in the community.
    reduce: "inject"