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Class: RuboCop::Cop::Style::ArrayIntersect

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::Base, ::RuboCop::Cop::AutocorrectLogic, ::RuboCop::Cop::IgnoredNode, ::RuboCop::Util, RuboCop::AST::Sexp
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/array_intersect.rb

Overview

In Ruby 3.1, Array#intersect? has been added.

This cop identifies places where:

  • (array1 & array2).any?

  • (array1.intersection(array2)).any?

  • array1.any? { |elem| array2.member?(elem) }

  • (array1 & array2).count > 0

  • (array1 & array2).size > 0

can be replaced with array1.intersect?(array2).

array1.intersect?(array2) is faster and more readable.

In cases like the following, compatibility is not ensured, so it will not be detected when using block argument.

([1] & [1,2]).any? { |x| false }    # => false
[1].intersect?([1,2]) { |x| false } # => true
Note
 Although Array#intersection can take zero or multiple arguments, only cases where exactly one argument is provided can be replaced with Array#intersect? and are handled by this cop.

Examples:

# bad
(array1 & array2).any?
(array1 & array2).empty?
(array1 & array2).none?

# bad
array1.intersection(array2).any?
array1.intersection(array2).empty?
array1.intersection(array2).none?

# bad
array1.any? { |elem| array2.member?(elem) }
array1.none? { |elem| array2.member?(elem) }

# good
array1.intersect?(array2)
!array1.intersect?(array2)

# bad
(array1 & array2).count > 0
(array1 & array2).count.positive?
(array1 & array2).count != 0

(array1 & array2).count == 0
(array1 & array2).count.zero?

# good
array1.intersect?(array2)

!array1.intersect?(array2)

AllCops:ActiveSupportExtensionsEnabled: false (default)

# good
(array1 & array2).present?
(array1 & array2).blank?

AllCops:ActiveSupportExtensionsEnabled: true

# bad
(array1 & array2).present?
(array1 & array2).blank?

# good
array1.intersect?(array2)
!array1.intersect?(array2)

Cop Safety Information:

  • This cop cannot guarantee that array1 and array2 are actually arrays while method intersect? is for arrays only.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

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::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_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

Instance Method Details

#any_none_block_intersection(node)

[ GitHub ] 

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 119



def_node_matcher :any_none_block_intersection, <<~PATTERN
  {
    (block
      (call $_receiver ${:any? :none?})
      (args (arg _key))
      (send $_argument :member? (lvar _key))
    )
    (numblock
      (call $_receiver ${:any? :none?}) 1
      (send $_argument :member? (lvar :_1))
    )
    (itblock
      (call $_receiver ${:any? :none?}) :it
      (send $_argument :member? (lvar :it))
    )
  }
PATTERN


  








  

    #bad_intersection?(node)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 168



def bad_intersection?(node)
  bad_intersection_check?(node, bad_intersection_predicates) ||
    intersection_size_check?(node)
end


  








  

    #bad_intersection_check?(node, predicates)  
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 94



def_node_matcher :bad_intersection_check?, <<~PATTERN
  $(call
    {
      (begin (send $_ :& $_))
      (call $!nil? :intersection $_)
    }
    $%1
  )
PATTERN


  








  

    #bad_intersection_predicates   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 173



def bad_intersection_predicates
  if active_support_extensions_enabled?
    ACTIVE_SUPPORT_PREDICATES
  else
    PREDICATES
  end
end


  








  

    #intersection_size_check?(node, predicates)  
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 105



def_node_matcher :intersection_size_check?, <<~PATTERN
  (call
    $(call
      {
        (begin (send $_ :& $_))
        (call $!nil? :intersection $_)
      }
      %ARRAY_SIZE_METHODS
    )
    {$:> (int 0) | $:positive? | $:!= (int 0) | $:== (int 0) | $:zero?}
  )
PATTERN


  








  

    #on_block(node)  
    Also known as: #on_numblock, #on_itblock
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 154



def on_block(node)
  return unless (receiver, method_name, argument = any_none_block_intersection(node))

  dot = node.send_node.loc.dot.source
  bang = method_name == :any? ? '' : '!'
  replacement = "#{bang}#{receiver.source}#{dot}intersect?(#{argument.source})"

  register_offense(node, replacement)
end


  








  

    #on_csend(node)  
  



  

    


Alias for #on_send.



  



  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 152



alias on_csend on_send


  








  

    #on_itblock(node)  
  



  

    


Alias for #on_block.



  



  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 164



alias on_itblock on_block


  








  

    #on_numblock(node)  
  



  

    


Alias for #on_block.



  



  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 163



alias on_numblock on_block


  








  

    #on_send(node)  
    Also known as: #on_csend
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 142



def on_send(node)
  return if node.block_literal?
  return unless (dot_node, receiver, argument, method_name = bad_intersection?(node))

  dot = dot_node.loc.dot.source
  bang = straight?(method_name) ? '' : '!'
  replacement = "#{bang}#{receiver.source}#{dot}intersect?(#{argument.source})"

  register_offense(node, replacement)
end


  








  

    #register_offense(node, replacement)   (private)
  

  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 185



def register_offense(node, replacement)
  message = format(MSG, replacement: replacement, existing: node.source)

  add_offense(node, message: message) do |corrector|
    corrector.replace(node, replacement)
  end
end


  








  

    #straight?(method_name)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/rubocop/cop/style/array_intersect.rb', line 181



def straight?(method_name)
  STRAIGHT_METHODS.include?(method_name.to_sym)
end