.rubocop.yml

AllCops:
  NewCops: enable

# We adopt "Semantic Block".
# In "Semantic Block" way, "{...}" block and "do ... end" block are
# NOT same semantics.
#
# * "{...}" block specifies last evaluated value.
#   Block caller can use block result.
# * "do ... end" block doesn't specify last evaluated value.
#   So, block caller MUST NOT use block result.
Style/BlockDelimiters:
  EnforcedStyle: semantic
  FunctionalMethods:
    - data # Data driven tests on test-unit.gem

# For low indent level.
Style/ClassAndModuleChildren:
  EnforcedStyle: compact

# From number of terminal lines - 2 ("def" line and "end" line).
Metrics/MethodLength:
  Max: 22

# "if !a" is better than "unless a", we think.
# Because condition(s) often will be appended another codition(s).
# In "unless a" case, we'll inverse codition(s).
#
# Which do you like?
# * unless: "unless a" + "&& b"
#   We'll waver between "unless a || !b" and "if !a && b".
#   In either case, our brain must inverse condition.
# * if !: "if !a" + "&& b"
#   We'll write "if !a && b" without inverse.
Style/NegatedIf:
  Enabled: false

# Sometimes we add "#{...}" to string which is already exists.
#
# Which do you like?
# * single_quotes: 'foo' + "#{a}" => "foo#{a}"
#   Oops, we must change from ' to ". And we take extra differences.
#   (Try "git diff --color-words=." or "git log -p --color-words=.")
# * double_quotes: "foo" + "#{a}" => "foo#{a}"
#   There is no problem on another case.
Style/StringLiterals:
  EnforcedStyle: double_quotes

# To define private constants.
Lint/UselessAccessModifier:
  Enabled: false

# Less code is better than more code.
Style/LambdaCall:
  EnforcedStyle: braces

# Less diff to last line changes.
Style/TrailingCommaInArguments:
  EnforcedStyleForMultiline: consistent_comma
Style/TrailingCommaInArrayLiteral:
  EnforcedStyleForMultiline: consistent_comma
Style/TrailingCommaInHashLiteral:
  EnforcedStyleForMultiline: consistent_comma

Style/TrailingCommaInBlockArgs:
  Enabled: true

# Not used.
Style/FrozenStringLiteralComment:
  EnforcedStyle: never

Metrics/BlockLength:
  ExcludedMethods:
    - data # Data driven test data on test-unit.gem
    - test # Test method on test-unit.gem
    - sub_test_case # Test grouping on test-unit.gem

# Distinguish hash from functional blocks.
Layout/SpaceInsideHashLiteralBraces:
  EnforcedStyle: no_space

# Write "return" is NOT redundant.
# Because if not "return", we don't know specified return value or
# last evaluated value.
# Sometimes we don't write YARD @return
# (private methods, method by define_method, and so on)
Style/RedundantReturn:
  Enabled: false

# REPL (eg. irb, pry, ...) friendly style.
Layout/DotPosition:
  EnforcedStyle: trailing

# We can care it. At own risk.
Style/MutableConstant:
  Enabled: false

Naming/MethodParameterName:
  AllowedNames:
    - mm # milli meters
    - pt # points
    - x # position-x
    - y # position-y
    - s # string

# For ruby-mode friendly
Layout/MultilineMethodCallIndentation:
  EnforcedStyle: indented_relative_to_receiver

# TODO: In "#{...}" as single_quotes, but in "%Q{#{...}}" as double_quotes
Style/StringLiteralsInInterpolation:
  Enabled: false