Class: RuboCop::Cop::Style::EvenOdd

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/even_odd.rb

Overview

This cop checks for places where Fixnum#even? or Fixnum#odd? should have been used.

Examples:


# bad
if x % 2 == 0

# good
if x.even?

Constant Summary collapse

MSG_EVEN =
'Replace with `Fixnum#even?`.'
MSG_ODD =
'Replace with `Fixnum#odd?`.'
ZERO =
s(:int, 0)
ONE =
s(:int, 1)
TWO =
s(:int, 2)

Constants included from Util

Util::ASGN_NODES, Util::EQUALS_ASGN_NODES, Util::OPERATOR_METHODS, Util::PROC_NEW_NODE, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #autocorrect?, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_name_with_namespace, cop_type, #debug?, #display_cop_names?, inherited, #initialize, #join_force?, lint?, #message, non_rails, qualified_cop_name, rails?, #relevant_file?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, block_length, command?, comment_line?, const_name, first_part_of_call_chain, lambda?, lambda_or_proc?, line_range, numeric_range_size, on_node, operator?, parentheses?, proc?, range_with_surrounding_space, source_range, strip_quotes, within_node?

Methods included from PathUtil

issue_deprecation_warning, match_path?, relative_path

Constructor Details

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

Instance Method Details

#on_send(node) ⇒ Object


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# File 'lib/rubocop/cop/style/even_odd.rb', line 24

def on_send(node)
  receiver, method, args = *node

  return unless [:==, :!=].include?(method)
  return unless div_by_2?(receiver)

  if args == ZERO
    add_offense(node,
                :expression,
                method == :== ? MSG_EVEN : MSG_ODD)
  elsif args == ONE
    add_offense(node,
                :expression,
                method == :== ? MSG_ODD : MSG_EVEN)
  end
end