.rubocop.yml

AllCops:
  TargetRubyVersion: 2.3
  # 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
  Exclude:
    - '**/migrate/**/*'
    - '**/templates/**/*'
    - '**/vendor/**/*'
    - 'actionpack/lib/action_dispatch/journey/parser.rb'

# 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

Layout/EmptyLineAfterMagicComment:
  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

Layout/FirstParameterIndentation:
  Enabled: true

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

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

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

Layout/LeadingCommentSpace:
  Enabled: true

Layout/SpaceAfterColon:
  Enabled: true

Layout/SpaceAfterComma:
  Enabled: true

Layout/SpaceAroundEqualsInParameterDefault:
  Enabled: true

Layout/SpaceAroundKeyword:
  Enabled: true

Layout/SpaceAroundOperators:
  Enabled: true

Layout/SpaceBeforeComma:
    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
  Exclude:
    - 'actionview/test/**/*.builder'
    - 'actionview/test/**/*.ruby'
    - 'actionpack/test/**/*.builder'
    - 'actionpack/test/**/*.ruby'
    - 'activestorage/db/migrate/**/*.rb'

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

# Use `foo { bar }` not `foo {bar}`.

# 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/TrailingBlankLines:
  Enabled: true

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

# Use quotes for string literals when they are enough.
Style/UnneededPercentQ:
  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

# Use my_method(my_arg) not my_method( my_arg ) or my_method my_arg.
Lint/RequireParentheses:
  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/CollectionMethods:
  Enabled: true
  PreferredMethods:
    # inject seems more common in the community.
    reduce: "inject"

# # Commonly used screens these days easily fit more than 80 characters.
# # Metrics/LineLength:
# #   Max: 120

# # 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

# The guiding principle of classes is SRP, SRP can't be accurately measured by LoC
Metrics/ClassLength:
  Max: 1500

# We do not need to support Ruby 1.9, so this is good to use.
Style/SymbolArray:
  Enabled: true

# Most readable form.
Layout/AlignHash:
  EnforcedHashRocketStyle: table
  EnforcedColonStyle: table

# Mixing the styles looks just silly.
Style/HashSyntax:
  EnforcedStyle: ruby19_no_mixed_keys

# has_key? and has_value? are far more readable than key? and value?
Style/PreferredHashMethods:
  Enabled: false

# String#% is by far the least verbose and only object oriented variant.
Style/FormatString:
  EnforcedStyle: percent

# Either allow this style or don't. Marking it as safe with parenthesis
# is silly. Let's try to live without them for now.
Style/ParenthesesAroundCondition:
  AllowSafeAssignment: false
Lint/AssignmentInCondition:
  AllowSafeAssignment: false

# A specialized exception class will take one or more arguments and construct the message from it.
# So both variants make sense.
Style/RaiseArgs:
  Enabled: false

# Indenting the chained dots beneath each other is not supported by this cop,
# see https://github.com/bbatsov/rubocop/issues/1633
Layout/MultilineOperationIndentation:
  Enabled: false

# Fail is an alias of raise. Avoid aliases, it's more cognitive load for no gain.
# The argument that fail should be used to abort the program is wrong too,
# there's Kernel#abort for that.
Style/SignalException:
  EnforcedStyle: only_raise

# Suppressing exceptions can be perfectly fine, and be it to avoid to
# explicitly type nil into the rescue since that's what you want to return,
# or suppressing LoadError for optional dependencies
Lint/HandleExceptions:
  Enabled: false

# { ... } for multi-line blocks is okay, follow Weirichs rule instead:
# https://web.archive.org/web/20140221124509/http://onestepback.org/index.cgi/Tech/Ruby/BraceVsDoEnd.rdoc
Style/BlockDelimiters:
  Enabled: false

# do / end blocks should be used for side effects,
# methods that run a block for side effects and have
# a useful return value are rare, assign the return
# value to a local variable for those cases.
Style/MethodCalledOnDoEndBlock:
  Enabled: true

# Enforcing the names of variables? To single letter ones? Just no.
Style/SingleLineBlockParams:
  Enabled: false

# Shadowing outer local variables with block parameters is often useful
# to not reinvent a new name for the same thing, it highlights the relation
# between the outer variable and the parameter. The cases where it's actually
# confusing are rare, and usually bad for other reasons already, for example
# because the method is too long.
Lint/ShadowingOuterLocalVariable:
  Enabled: false

# Check with yard instead.
Style/Documentation:
  Enabled: false

# This is just silly. Calling the argument `other` in all cases makes no sense.
Naming/BinaryOperatorParameterName:
  Enabled: false

# There are valid cases, for example debugging Cucumber steps,
# also they'll fail CI anyway
Lint/Debugger:
  Enabled: false