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Class: RuboCop::Cop::Naming::BlockForwarding

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

Overview

In Ruby 3.1, anonymous block forwarding has been added.

This cop identifies places where do_something(&block) can be replaced by do_something(&).

It also supports the opposite style by alternative explicit option. You can specify the block variable name for autocorrection with BlockForwardingName. The default variable name is block. If the name is already in use, it will not be autocorrected.

Note

Because of a bug in Ruby 3.3.0, when a block is referenced inside of another block, no offense will be registered until Ruby 3.4:

def foo(&block)
  # Using an anonymous block would be a syntax error on Ruby 3.3.0
  block_method { bar(&block) }
end

Examples:

EnforcedStyle: anonymous (default)

# bad
def foo(&block)
  bar(&block)
end

# good
def foo(&)
  bar(&)
end

EnforcedStyle: explicit

# bad
def foo(&)
  bar(&)
end

# good
def foo(&block)
  bar(&block)
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

SYMBOL_TO_STRING_CACHE

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

support_autocorrect?

::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::TargetRubyVersion - Extended

maximum_target_ruby_version, minimum_target_ruby_version, required_maximum_ruby_version, required_minimum_ruby_version, support_target_ruby_version?

::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::ConfigurableEnforcedStyle - Included

#detected_style, #detected_style=, #no_acceptable_style?, #style_configured?

::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::RangeHelp - Included

#add_range,
#arguments_range

A range containing the first to the last argument of a method call or method definition.
#column_offset_between,
#contents_range

A range containing only the contents of a literal with delimiters (e.g.
#directions,
#effective_column

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.
#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

#alternative_style, #alternative_styles, #ambiguous_style_detected,
#conflicting_styles_detected

Alias for ConfigurableEnforcedStyle#no_acceptable_style!.
#correct_style_detected, #no_acceptable_style!, #opposite_style_detected, #style, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected,
#unrecognized_style_detected

Alias for ConfigurableEnforcedStyle#no_acceptable_style!.

::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_gem_version

Returns a gems locked versions (i.e.
#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, #eol_comment, #eol_comment_would_be_inside_literal?, #heredoc_range, #line_with_eol_comment_too_long?, #max_line_length, #multiline_ranges, #multiline_string?,
#range_by_lines

Expand the given range to include all of any lines it covers.
#range_of_first_line, #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

Class Method Details

.autocorrect_incompatible_with

[ GitHub ] 

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 64



def self.autocorrect_incompatible_with
  [Lint::AmbiguousOperator, Style::ArgumentsForwarding, Style::ExplicitBlockArgument]
end


  







Instance Method Details



  

    #anonymous_block_argument?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 118



def anonymous_block_argument?(node)
  node.blockarg_type? && node.name.nil?
end


  








  

    #block_argument_name_matched?(block_pass_node, last_argument)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 101



def block_argument_name_matched?(block_pass_node, last_argument)
  return false if block_pass_node.children.first&.sym_type?

  last_argument.source == block_pass_node.source
end


  








  

    #block_forwarding_name   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 150



def block_forwarding_name
  cop_config.fetch('BlockForwardingName', 'block')
end


  








  

    #expected_block_forwarding_style?(node, last_argument)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 91



def expected_block_forwarding_style?(node, last_argument)
  if style == :anonymous
    !explicit_block_argument?(last_argument) ||
      use_kwarg_in_method_definition?(node) ||
      use_block_argument_as_local_variable?(node, last_argument.source[1..])
  else
    !anonymous_block_argument?(last_argument)
  end
end


  








  

    #explicit_block_argument?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 122



def explicit_block_argument?(node)
  node.blockarg_type? && !node.name.nil?
end


  








  

    #invalidates_syntax?(block_pass_node)  ⇒ Boolean  (private)
  



  

    


Ruby 3.3.0 had a bug where accessing an anonymous block argument inside of a block
was a syntax error in unambiguous cases: https://bugs.ruby-lang.org/issues/20090
We disallow this also for earlier Ruby versions so that code is forwards compatible.



  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 110



def invalidates_syntax?(block_pass_node)
  target_ruby_version <= 3.3 && block_pass_node.each_ancestor(:any_block).any?
end


  








  

    #on_def(node)  
    Also known as: #on_defs
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 68



def on_def(node)
  return if node.arguments.empty?

  last_argument = node.last_argument
  return if expected_block_forwarding_style?(node, last_argument)

  forwarded_args = node.each_descendant(:block_pass).with_object([]) do |block_pass, result|
    return nil if invalidates_syntax?(block_pass)
    next unless block_argument_name_matched?(block_pass, last_argument)

    result << block_pass
  end

  forwarded_args.each do |forwarded_arg|
    register_offense(forwarded_arg, node)
  end

  register_offense(last_argument, node)
end


  








  

    #on_defs(node)  
  



  

    


Alias for #on_def.



  



  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 87



alias on_defs on_def


  








  

    #register_offense(block_argument, node)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 126



def register_offense(block_argument, node)
  add_offense(block_argument, message: format(MSG, style: style)) do |corrector|
    if style == :anonymous
      corrector.replace(block_argument, '&')

      arguments = block_argument.parent

      add_parentheses(arguments, corrector) unless arguments.parenthesized_call?
    else
      unless use_block_argument_as_local_variable?(node, block_forwarding_name)
        corrector.replace(block_argument, "&#{block_forwarding_name}")
      end
    end
  end
end


  








  

    #use_block_argument_as_local_variable?(node, last_argument)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 142



def use_block_argument_as_local_variable?(node, last_argument)
  return false if node.body.nil?

  node.body.each_node(:lvar, :lvasgn).any? do |lvar|
    !lvar.parent.block_pass_type? && lvar.node_parts[0].to_s == last_argument
  end
end


  








  

    #use_kwarg_in_method_definition?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/naming/block_forwarding.rb', line 114



def use_kwarg_in_method_definition?(node)
  node.arguments.each_descendant(:kwarg, :kwoptarg).any?
end