.rubocop.yml

require:
  - rubocop-performance
AllCops:
  TargetRubyVersion: 2.5
  # RuboCop has a bunch of cops enabled by default. This setting tells RuboCop
  # to ignore them, so only the ones explicitly set in this file are enabled.
  DisabledByDefault: true

Metrics/LineLength:
  Max: 120 # Try to reduce this over time

  # Prefer &&/|| over and/or.
Style/AndOr:
  Enabled: true

# Do not use braces for hash literals when they are the last argument of a
# method call.
Style/BracesAroundHashParameters:
  Enabled: true
  EnforcedStyle: context_dependent

# Align `when` with `case`.
Layout/CaseIndentation:
  Enabled: true

# Align comments with method definitions.
Layout/CommentIndentation:
  Enabled: true

Layout/ElseAlignment:
  Enabled: true

# Align `end` with the matching keyword or starting expression except for
# assignments, where it should be aligned with the LHS.
Layout/EndAlignment:
  Enabled: true
  EnforcedStyleAlignWith: variable
  AutoCorrect: true

Layout/EmptyLineAfterMagicComment:
  Enabled: true

Layout/EmptyLinesAroundAccessModifier:
  Enabled: true
  EnforcedStyle: only_before

Layout/EmptyLinesAroundBlockBody:
  Enabled: true

# In a regular class definition, no empty lines around the body.
Layout/EmptyLinesAroundClassBody:
  Enabled: true

# In a regular method definition, no empty lines around the body.
Layout/EmptyLinesAroundMethodBody:
  Enabled: true

# In a regular module definition, no empty lines around the body.
Layout/EmptyLinesAroundModuleBody:
  Enabled: true

# Use Ruby >= 1.9 syntax for hashes. Prefer { a: :b } over { :a => :b }.
Style/HashSyntax:
  Enabled: true

Layout/FirstArgumentIndentation:
  Enabled: true

# Method definitions after `private` or `protected` isolated calls need one
# extra level of indentation.
Layout/IndentationConsistency:
  Enabled: true
  EnforcedStyle: indented_internal_methods

# Two spaces, no tabs (for indentation).
Layout/IndentationWidth:
  Enabled: true

Layout/LeadingCommentSpace:
  Enabled: true

Layout/SpaceAfterColon:
  Enabled: true

Layout/SpaceAfterComma:
  Enabled: true

Layout/SpaceAfterSemicolon:
  Enabled: true

Layout/SpaceAroundEqualsInParameterDefault:
  Enabled: true

Layout/SpaceAroundKeyword:
  Enabled: true

Layout/SpaceAroundOperators:
  Enabled: true

Layout/SpaceBeforeComma:
  Enabled: true

Layout/SpaceBeforeComment:
  Enabled: true

Layout/SpaceBeforeFirstArg:
  Enabled: true

Style/DefWithParentheses:
  Enabled: true

# Defining a method with parameters needs parentheses.
Style/MethodDefParentheses:
  Enabled: true

Style/FrozenStringLiteralComment:
  Enabled: true
  EnforcedStyle: always

Style/RedundantFreeze:
  Enabled: true

# Use `foo {}` not `foo{}`.
Layout/SpaceBeforeBlockBraces:
  Enabled: true

# Use `foo { bar }` not `foo {bar}`.
Layout/SpaceInsideBlockBraces:
  Enabled: true
  EnforcedStyleForEmptyBraces: space

# Use `{ a: 1 }` not `{a:1}`.
Layout/SpaceInsideHashLiteralBraces:
  Enabled: true

Layout/SpaceInsideParens:
  Enabled: true

# Check quotes usage according to lint rule below.
Style/StringLiterals:
  Enabled: true
  EnforcedStyle: double_quotes

# Detect hard tabs, no hard tabs.
Layout/Tab:
  Enabled: true

# Blank lines should not have any spaces.
Layout/TrailingEmptyLines:
  Enabled: true

# No trailing whitespace.
Layout/TrailingWhitespace:
  Enabled: true

# Use quotes for string literals when they are enough.
Style/RedundantPercentQ:
  Enabled: true

Lint/AmbiguousOperator:
  Enabled: true

Lint/AmbiguousRegexpLiteral:
  Enabled: true
  # Use my_method(my_arg) not my_method( my_arg ) or my_method my_arg.
Lint/RequireParentheses:
  Enabled: true

Lint/ShadowingOuterLocalVariable:
  Enabled: true

Lint/RedundantStringCoercion:
  Enabled: true

Lint/UriEscapeUnescape:
  Enabled: true

Lint/UselessAssignment:
  Enabled: true

Lint/DeprecatedClassMethods:
  Enabled: true

Style/ParenthesesAroundCondition:
  Enabled: true

Style/RedundantBegin:
  Enabled: true

Style/RedundantReturn:
  Enabled: true
  AllowMultipleReturnValues: true

Style/Semicolon:
  Enabled: true
  AllowAsExpressionSeparator: true

# Prefer Foo.method over Foo::method
Style/ColonMethodCall:
  Enabled: true

Style/TrivialAccessors:
  Enabled: true

Performance/FlatMap:
  Enabled: true

Performance/RedundantMerge:
  Enabled: true

Performance/StartWith:
  Enabled: true

Performance/EndWith:
  Enabled: true

Performance/RegexpMatch:
  Enabled: true

Performance/ReverseEach:
  Enabled: true

Performance/UnfreezeString:
  Enabled: true