class RuboCop::Cop::Lint::StructNewOverride

Checks unexpected overrides of the ‘Struct` built-in methods via `Struct.new`.

@example

# bad
Bad = Struct.new(:members, :clone, :count)
b = Bad.new([], true, 1)
b.members #=> [] (overriding `Struct#members`)
b.clone #=> true (overriding `Object#clone`)
b.count #=> 1 (overriding `Enumerable#count`)

# good
Good = Struct.new(:id, :name)
g = Good.new(1, "foo")
g.members #=> [:id, :name]
g.clone #=> #<struct Good id=1, name="foo">
g.count #=> 2

Constants

MSG
RESTRICT_ON_SEND
STRUCT_MEMBER_NAME_TYPES
STRUCT_METHOD_NAMES

Public Instance Methods

on_send(node) click to toggle source
# File lib/rubocop/cop/lint/struct_new_override.rb, line 38
def on_send(node)
  return unless struct_new(node)

  node.arguments.each_with_index do |arg, index|
    # Ignore if the first argument is a class name
    next if index.zero? && arg.str_type?

    # Ignore if the argument is not a member name
    next unless STRUCT_MEMBER_NAME_TYPES.include?(arg.type)

    member_name = arg.value

    next unless STRUCT_METHOD_NAMES.include?(member_name.to_sym)

    message = format(MSG, member_name: member_name.inspect, method_name: member_name.to_s)
    add_offense(arg, message: message)
  end
end