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Class: RuboCop::Cop::Lint::UselessRuby2Keywords

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
self, ::RuboCop::Cop::Base, ::RuboCop::Cop::AutocorrectLogic, ::RuboCop::Cop::IgnoredNode, ::RuboCop::Util, RuboCop::AST::Sexp
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/lint/useless_ruby2_keywords.rb

Overview

Looks for ruby2_keywords calls for methods that do not need it.

ruby2_keywords should only be called on methods that accept an argument splat (*args) but do not explicit keyword arguments (k: or k: true) or a keyword splat (**kwargs).

Examples:

# good (splat argument without keyword arguments)
ruby2_keywords def foo(*args); end

# bad (no arguments)
ruby2_keywords def foo; end

# good
def foo; end

# bad (positional argument)
ruby2_keywords def foo(arg); end

# good
def foo(arg); end

# bad (double splatted argument)
ruby2_keywords def foo(**args); end

# good
def foo(**args); end

# bad (keyword arguments)
ruby2_keywords def foo(i:, j:); end

# good
def foo(i:, j:); end

# bad (splat argument with keyword arguments)
ruby2_keywords def foo(*args, i:, j:); end

# good
def foo(*args, i:, j:); end

# bad (splat argument with double splat)
ruby2_keywords def foo(*args, **kwargs); end

# good
def foo(*args, **kwargs); end

# bad (ruby2_keywords given a symbol)
def foo; end
ruby2_keywords :foo

# good
def foo; end

# bad (ruby2_keywords with dynamic method)
define_method(:foo) { |arg| }
ruby2_keywords :foo

# good
define_method(:foo) { |arg| }

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::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

::RuboCop::Cop::Base - Inherited

#active_support_extensions_enabled?, #always_autocorrect?, #config, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #processed_source, #string_literals_frozen_by_default?, #target_satisfies_all_gem_version_requirements?

::RuboCop::Cop::AutocorrectLogic - Included

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Instance Method Summary

::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

#disable_offense, #disable_offense_at_end_of_line, #disable_offense_before_and_after, #disable_offense_with_eol_or_surround_comment, #max_line_length,
#range_by_lines

Expand the given range to include all of any lines it covers.
#range_of_first_line, #range_overlaps_offense?, #string_continuation, #string_continuation?, #surrounding_heredoc, #surrounding_percent_array

::RuboCop::Cop::IgnoredNode - Included

#ignore_node, #ignored_node?, #part_of_ignored_node?, #ignored_nodes

Constructor Details

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

Instance Method Details

#allowed_arguments(arguments) (private)

ruby2_keywords is only allowed if there’s a restarg and no keyword arguments

[ GitHub ] 

  


# File 'lib/rubocop/cop/lint/useless_ruby2_keywords.rb', line 118



def allowed_arguments(arguments)
  return false if arguments.empty?

  arguments.each_child_node(:restarg).any? &&
    arguments.each_child_node(:kwarg, :kwoptarg, :kwrestarg).none?
end


  








  

    #find_method_definition(node, method_name)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/useless_ruby2_keywords.rb', line 109



def find_method_definition(node, method_name)
  node.each_ancestor.lazy.map do |ancestor|
    ancestor.each_child_node(:def, :block, :numblock).find do |child|
      method_definition(child, method_name)
    end
  end.find(&:itself)
end


  








  

    #inspect_def(node, def_node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/useless_ruby2_keywords.rb', line 91



def inspect_def(node, def_node)
  return if allowed_arguments(def_node.arguments)

  add_offense(node.loc.selector, message: format(MSG, method_name: def_node.method_name))
end


  








  

    #inspect_sym(node, sym_node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/useless_ruby2_keywords.rb', line 97



def inspect_sym(node, sym_node)
  return unless node.parent

  method_name = sym_node.value
  definition = find_method_definition(node, method_name)

  return unless definition
  return if allowed_arguments(definition.arguments)

  add_offense(node, message: format(MSG, method_name: method_name))
end


  








  

    #method_definition(node, method_name)  
  



  

    


Looks for statically or dynamically defined methods with a given name



  



  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/useless_ruby2_keywords.rb', line 72



def_node_matcher :method_definition, <<~PATTERN
  {
    (def %1 ...)
    ({block numblock} (send _ :define_method (sym %1)) ...)
  }
PATTERN


  








  

    #on_send(node)  
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/lint/useless_ruby2_keywords.rb', line 79



def on_send(node)
  return unless (first_argument = node.first_argument)

  if first_argument.def_type?
    inspect_def(node, first_argument)
  elsif node.first_argument.sym_type?
    inspect_sym(node, first_argument)
  end
end