class RuboCop::Cop::Style::TrivialAccessors

This cop looks for trivial reader/writer methods, that could have been created with the attr_* family of functions automatically.

@example

# bad
def foo
  @foo
end

def bar=(val)
  @bar = val
end

def self.baz
  @baz
end

# good
attr_reader :foo
attr_writer :bar

class << self
  attr_reader :baz
end

Constants

MSG

Public Instance Methods

autocorrect(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 42
def autocorrect(node)
  parent = node.parent
  return if parent&.send_type?

  if node.def_type?
    autocorrect_instance(node)
  elsif node.defs_type? && node.children.first.self_type?
    autocorrect_class(node)
  end
end
on_def(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 33
def on_def(node)
  return if top_level_node?(node)
  return if in_module_or_instance_eval?(node)
  return if ignore_class_methods? && node.defs_type?

  on_method_def(node)
end
Also aliased as: on_defs
on_defs(node)
Alias for: on_def

Private Instance Methods

accessor(kind, method_name) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 154
def accessor(kind, method_name)
  "attr_#{kind} :#{method_name.to_s.chomp('=')}"
end
allow_dsl_writers?() click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 90
def allow_dsl_writers?
  cop_config['AllowDSLWriters']
end
allow_predicates?() click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 86
def allow_predicates?
  cop_config['AllowPredicates']
end
allowed_method?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 126
def allowed_method?(node)
  whitelist.include?(node.method_name) ||
    exact_name_match? && !names_match?(node)
end
allowed_reader?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 135
def allowed_reader?(node)
  allow_predicates? && node.predicate_method?
end
allowed_writer?(method_name) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 131
def allowed_writer?(method_name)
  allow_dsl_writers? && dsl_writer?(method_name)
end
autocorrect_class(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 169
def autocorrect_class(node)
  kind = trivial_accessor_kind(node)

  return unless names_match?(node) && kind

  lambda do |corrector|
    indent = ' ' * node.loc.column
    corrector.replace(
      node.source_range,
      ['class << self',
       "#{indent}  #{accessor(kind, node.method_name)}",
       "#{indent}end"].join("\n")
    )
  end
end
autocorrect_instance(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 158
def autocorrect_instance(node)
  kind = trivial_accessor_kind(node)

  return unless names_match?(node) && !node.predicate_method? && kind

  lambda do |corrector|
    corrector.replace(node.source_range,
                      accessor(kind, node.method_name))
  end
end
dsl_writer?(method_name) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 103
def dsl_writer?(method_name)
  !method_name.to_s.end_with?('=')
end
exact_name_match?() click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 82
def exact_name_match?
  cop_config['ExactNameMatch']
end
ignore_class_methods?() click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 94
def ignore_class_methods?
  cop_config['IgnoreClassMethods']
end
in_module_or_instance_eval?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 55
def in_module_or_instance_eval?(node)
  node.each_ancestor(:block, :class, :sclass, :module).each do |pnode|
    case pnode.type
    when :class, :sclass
      return false
    when :module
      return true
    else
      return true if pnode.method_name == :instance_eval
    end
  end
  false
end
looks_like_trivial_reader?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 112
def looks_like_trivial_reader?(node)
  !node.arguments? && node.body && node.body.ivar_type?
end
names_match?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 139
def names_match?(node)
  ivar_name, = *node.body

  node.method_name.to_s.sub(/[=?]$/, '') == ivar_name[1..-1]
end
on_method_def(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 69
def on_method_def(node)
  kind = if trivial_reader?(node)
           'reader'
         elsif trivial_writer?(node)
           'writer'
         end
  return unless kind

  add_offense(node,
              location: :keyword,
              message: format(MSG, kind: kind))
end
top_level_node?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 185
def top_level_node?(node)
  node.parent.nil?
end
trivial_accessor_kind(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 145
def trivial_accessor_kind(node)
  if trivial_writer?(node) &&
     !dsl_writer?(node.method_name)
    'writer'
  elsif trivial_reader?(node)
    'reader'
  end
end
trivial_reader?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 107
def trivial_reader?(node)
  looks_like_trivial_reader?(node) &&
    !allowed_method?(node) && !allowed_reader?(node)
end
trivial_writer?(node) click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 116
def trivial_writer?(node)
  looks_like_trivial_writer?(node) &&
    !allowed_method?(node) && !allowed_writer?(node.method_name)
end
whitelist() click to toggle source
# File lib/rubocop/cop/style/trivial_accessors.rb, line 98
def whitelist
  whitelist = cop_config['Whitelist']
  Array(whitelist).map(&:to_sym) + [:initialize]
end