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Class: RuboCop::Cop::Style::MethodCallWithoutArgsParentheses

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::AutoCorrector, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/method_call_without_args_parentheses.rb

Overview

Checks for unwanted parentheses in parameterless method calls.

This cop’s allowed methods can be customized with ::RuboCop::Cop::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.

Examples:

# bad
object.some_method()

# good
object.some_method

AllowedMethods: [] (default)

# bad
object.foo()

AllowedMethods: [foo]

# good
object.foo()

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

.gem_requirements, .lint?,
.support_autocorrect?

Returns if class supports autocorrect.

.support_multiple_source?

Override if your cop should be called repeatedly for multiple investigations Between calls to on_new_investigation and on_investigation_end, the result of processed_source will remain constant.

Class Method Summary

::RuboCop::Cop::Base - Inherited

.autocorrect_incompatible_with

List of cops that should not try to autocorrect at the same time as this cop.

.badge

Naming.

.callbacks_needed, .cop_name, .department,
.documentation_url

Returns a url to view this cops documentation online.

.exclude_from_registry

Call for abstract Cop classes.

.inherited,
.joining_forces

Override and return the Force class(es) you need to join.

.match?

Returns true if the cop name or the cop namespace matches any of the given names.

.new,
.requires_gem

Register a version requirement for the given gem name.

.restrict_on_send

::RuboCop::ExcludeLimit - Extended

exclude_limit

Sets up a configuration option to have an exclude limit tracked.

transform

Instance Attribute Summary

Instance Method Summary

::RuboCop::Cop::AllowedPattern - Included

::RuboCop::Cop::AllowedMethods - Included

::RuboCop::Cop::Base - Inherited

#add_global_offense

Adds an offense that has no particular location.

#add_offense

Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.

#begin_investigation

Called before any investigation.

#callbacks_needed,
#cop_config

Configuration Helpers.

#cop_name, #excluded_file?,
#external_dependency_checksum

This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:

#inspect,
#message

Gets called if no message is specified when calling add_offense or add_global_offense Cops are discouraged to override this; instead pass your message directly.

#name

Alias for Base#cop_name.

#offenses,
#on_investigation_end

Called after all on_…​

#on_new_investigation

Called before all on_…​

#on_other_file

Called instead of all on_…​

#parse

There should be very limited reasons for a Cop to do it’s own parsing.

#parser_engine,
#ready

Called between investigations.

#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument

Reserved for Cop::Cop.

#complete_investigation

Called to complete an investigation.

#correct, #current_corrector,
#current_offense_locations

Reserved for Commissioner:

#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range,
#reset_investigation

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#allowed_method_name?(name) ⇒ Boolean (private)

[ GitHub ]

  
# 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) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/method_call_without_args_parentheses.rb', line 96

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`.
    next if asgn_node.shorthand_asgn? && asgn_node.lhs.send_type?

    yield asgn_node
  end
end

#default_argument?(node) ⇒ Boolean (private)

[ GitHub ]

  
# 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) ⇒ Boolean (private)

[ GitHub ]

  
# 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) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/method_call_without_args_parentheses.rb', line 113

def offense_range(node)
  node.loc.begin.join(node.loc.end)
end

#on_send(node)

[ GitHub ]

  
# 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

#parenthesized_it_method_in_block?(node) ⇒ Boolean (private)

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

[ GitHub ]

  
# File 'lib/rubocop/cop/style/method_call_without_args_parentheses.rb', line 88

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) (private)

[ GitHub ]

  
# 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) ⇒ Boolean (private)

[ GitHub ]

  
# 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|
    if asgn_node.masgn_type?
      variable_in_mass_assignment?(node.method_name, asgn_node)
    else
      asgn_node.loc.name.source == node.method_name.to_s
    end
  end
end

#variable_in_mass_assignment?(variable_name, node) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/method_call_without_args_parentheses.rb', line 109

def variable_in_mass_assignment?(variable_name, node)
  node.assignments.any? { |n| n.name == variable_name }
end