Sha256: 71a281aacfbf35a8e86bb5b6f28c4e4b9fb4165591be7195274c13fdeddd1d91
Contents?: true
Size: 1.72 KB
Versions: 13
Compression:
Stored size: 1.72 KB
Contents
# frozen_string_literal: true
module RuboCop
module Cop
module Performance
# This cop identifies use of `Regexp#match` or `String#match in a context
# where the integral return value of `=~` would do just as well.
#
# @example
# @bad
# do_something if str.match(/regex/)
# while regex.match('str')
# do_something
# end
#
# @good
# method(str.match(/regex/))
# return regex.match('str')
class RedundantMatch < Cop
MSG = 'Use `=~` in places where the `MatchData` returned by ' \
'`#match` will not be used.'.freeze
# 'match' is a fairly generic name, so we don't flag it unless we see
# a string or regexp literal on one side or the other
def_node_matcher :match_call?, <<-END
{(send {str regexp} :match _)
(send !nil :match {str regexp})}
END
def_node_matcher :only_truthiness_matters?, <<-END
^({if while until case while_post until_post} equal?(%0) ...)
END
def on_send(node)
return unless match_call?(node) &&
(!node.value_used? || only_truthiness_matters?(node)) &&
!(node.parent && node.parent.block_type?)
add_offense(node, :expression, MSG)
end
def autocorrect(node)
receiver, _method, arg = *node
# Regexp#match can take a second argument, but this cop doesn't
# register an offense in that case
return unless arg.regexp_type?
new_source = receiver.source + ' =~ ' + arg.source
->(corrector) { corrector.replace(node.source_range, new_source) }
end
end
end
end
end
Version data entries
13 entries across 13 versions & 2 rubygems