Class: RuboCop::Cop::Style::BitwisePredicate

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector, TargetRubyVersion
Defined in:
lib/rubocop/cop/style/bitwise_predicate.rb

Overview

Prefer bitwise predicate methods over direct comparison operations.

Examples:


# bad - checks any set bits
(variable & flags).positive?

# good
variable.anybits?(flags)

# bad - checks all set bits
(variable & flags) == flags

# good
variable.allbits?(flags)

# bad - checks no set bits
(variable & flags).zero?

# good
variable.nobits?(flags)

Constant Summary collapse

MSG = 
'Replace with `%<preferred>s` for comparison with bit flags.'
RESTRICT_ON_SEND = 
%i[!= == > >= positive? zero?].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from TargetRubyVersion

minimum_target_ruby_version, required_minimum_ruby_version, support_target_ruby_version?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

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

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

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

Instance Method Details

#allbits?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/bitwise_predicate.rb', line 52

def_node_matcher :allbits?, <<~PATTERN
  {
    (send (begin (send _ :& _flags)) :== _flags)
    (send (begin (send _flags :& _)) :== _flags)
  }
PATTERN

#anybits?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/bitwise_predicate.rb', line 42

def_node_matcher :anybits?, <<~PATTERN
  {
    (send #bit_operation? :positive?)
    (send #bit_operation? :> (int 0))
    (send #bit_operation? :>= (int 1))
    (send #bit_operation? :!= (int 0))
  }
PATTERN

#bit_operation?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/bitwise_predicate.rb', line 68

def_node_matcher :bit_operation?, <<~PATTERN
  (begin
    (send _ :& _))
PATTERN

#nobits?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/bitwise_predicate.rb', line 60

def_node_matcher :nobits?, <<~PATTERN
  {
    (send #bit_operation? :zero?)
    (send #bit_operation? :== (int 0))
  }
PATTERN

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/bitwise_predicate.rb', line 73

def on_send(node)
  return unless node.receiver.begin_type?
  return unless (preferred_method = preferred_method(node))

  bit_operation = node.receiver.children.first
  lhs, _operator, rhs = *bit_operation
  preferred = "#{lhs.source}.#{preferred_method}(#{rhs.source})"

  add_offense(node, message: format(MSG, preferred: preferred)) do |corrector|
    corrector.replace(node, preferred)
  end
end