class RuboCop::Cop::Style::MethodCallWithoutArgsParentheses

Checks for unwanted parentheses in parameterless method calls.

This cop’s allowed methods can be customized with ‘AllowedMethods`. By default, there are no allowed methods.

NOTE: This cop allows the use of ‘it()` without arguments in blocks, as in `0.times { it() }`, following `Lint/ItWithoutArgumentsInBlock` cop.

@example

# bad
object.some_method()

# good
object.some_method

@example AllowedMethods: [] (default)

# bad
object.foo()

@example AllowedMethods: [foo]

# good
object.foo()

Constants

MSG

Public Instance Methods

on_send(node) click to toggle source

rubocop:disable Metrics/CyclomaticComplexity

# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 37
def on_send(node)
  return unless !node.arguments? && node.parenthesized?
  return if ineligible_node?(node)
  return if default_argument?(node)
  return if allowed_method_name?(node.method_name)
  return if same_name_assignment?(node)
  return if parenthesized_it_method_in_block?(node)

  register_offense(node)
end

Private Instance Methods

allowed_method_name?(name) click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 66
def allowed_method_name?(name)
  allowed_method?(name) || matches_allowed_pattern?(name)
end
any_assignment?(node) { |asgn_node| ... } click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 94
def any_assignment?(node)
  node.each_ancestor(*AST::Node::ASSIGNMENTS).any? do |asgn_node|
    # `obj.method = value` parses as (send ... :method= ...), and will
    # not be returned as an `asgn_node` here, however,
    # `obj.method ||= value` parses as (or-asgn (send ...) ...)
    # which IS an `asgn_node`. Similarly, `obj.method += value` parses
    # as (op-asgn (send ...) ...), which is also an `asgn_node`.
    if asgn_node.shorthand_asgn?
      asgn_node, _value = *asgn_node
      next if asgn_node.send_type?
    end

    yield asgn_node
  end
end
default_argument?(node) click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 62
def default_argument?(node)
  node.parent&.optarg_type?
end
ineligible_node?(node) click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 58
def ineligible_node?(node)
  node.camel_case_method? || node.implicit_call? || node.prefix_not?
end
offense_range(node) click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 117
def offense_range(node)
  node.loc.begin.join(node.loc.end)
end
parenthesized_it_method_in_block?(node) click to toggle source

Respects ‘Lint/ItWithoutArgumentsInBlock` cop and the following Ruby 3.3’s warning:

$ ruby -e ‘0.times { begin; it; end }’ -e:1: warning: ‘it` calls without arguments will refer to the first block param in Ruby 3.4; use it() or self.it

# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 86
def parenthesized_it_method_in_block?(node)
  return false unless node.method?(:it)
  return false unless (block_node = node.each_ancestor(:block).first)
  return false unless block_node.arguments.empty_and_without_delimiters?

  !node.receiver && node.arguments.empty? && !node.block_literal?
end
register_offense(node) click to toggle source

rubocop:enable Metrics/CyclomaticComplexity

# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 51
def register_offense(node)
  add_offense(offense_range(node)) do |corrector|
    corrector.remove(node.loc.begin)
    corrector.remove(node.loc.end)
  end
end
same_name_assignment?(node) click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 70
def same_name_assignment?(node)
  return false if node.receiver

  any_assignment?(node) do |asgn_node|
    next variable_in_mass_assignment?(node.method_name, asgn_node) if asgn_node.masgn_type?

    asgn_node.loc.name.source == node.method_name.to_s
  end
end
variable_in_mass_assignment?(variable_name, node) click to toggle source
# File lib/rubocop/cop/style/method_call_without_args_parentheses.rb, line 110
def variable_in_mass_assignment?(variable_name, node)
  mlhs_node, _mrhs_node = *node
  var_nodes = *mlhs_node

  var_nodes.any? { |n| n.to_a.first == variable_name }
end