class RuboCop::Cop::Style::OptionalArguments

This cop checks for optional arguments to methods that do not come at the end of the argument list

@example

# bad
def foo(a = 1, b, c)
end

# good
def baz(a, b, c = 1)
end

def foobar(a = 1, b = 2, c = 3)
end

Constants

MSG

Public Instance Methods

on_def(node) click to toggle source
# File lib/rubocop/cop/style/optional_arguments.rb, line 24
def on_def(node)
  _method, arguments, = *node
  arguments = *arguments
  optarg_positions = []
  arg_positions = []

  arguments.each_with_index do |argument, index|
    optarg_positions << index if argument.optarg_type?
    arg_positions << index if argument.arg_type?
  end

  return if optarg_positions.empty? || arg_positions.empty?

  optarg_positions.each do |optarg_position|
    # there can only be one group of optional arguments
    break if optarg_position > arg_positions.max
    argument = arguments[optarg_position]
    arg, = *argument

    add_offense(argument, :expression, format(MSG, arg))
  end
end