Sha256: 994e283ec15cc074ff775b0be2ff9cefcb9af23420e6f3162ba09faf5da10091
Contents?: true
Size: 1.72 KB
Versions: 9
Compression:
Stored size: 1.72 KB
Contents
# encoding: utf-8
module RuboCop
module Cop
module Style
# This cop checks for places where Fixnum#even? or Fixnum#odd?
# should have been used.
#
# @example
#
# # bad
# if x % 2 == 0
#
# # good
# if x.even?
class EvenOdd < Cop
MSG = 'Replace with `Fixnum#%s?`.'
ZERO = s(:int, 0)
ONE = s(:int, 1)
TWO = s(:int, 2)
def on_send(node)
offense = offense_type(node)
add_offense(node, :expression, format(MSG, offense)) if offense
end
def autocorrect(node)
correction = "#{base_number(node)}.#{offense_type(node)}?"
->(corrector) { corrector.replace(node.loc.expression, correction) }
end
private
def base_number(node)
receiver, = *node
node = expression(receiver)
node.children[0].loc.expression.source
end
def offense_type(node)
receiver, method, args = *node
return unless [:==, :!=].include?(method)
return unless div_by_2?(receiver)
if args == ZERO
method == :== ? :even : :odd
elsif args == ONE
method == :== ? :odd : :even
end
end
def div_by_2?(node)
node = expression(node)
_receiver, method, args = *node
method == :% && args == TWO
end
def expression(node)
return unless node
# check for scenarios like (x % 2) == 0
if node.type == :begin && node.children.size == 1
node = node.children.first
end
return unless node.type == :send
node
end
end
end
end
end
Version data entries
9 entries across 9 versions & 1 rubygems