class RuboCop::Cop::Performance::StartWith
This cop identifies unnecessary use of a regex where `String#start_with?` would suffice.
This cop has `SafeMultiline` configuration option that `true` by default because `^start` is unsafe as it will behave incompatible with `start_with?` for receiver is multiline string.
@example
# bad 'abc'.match?(/\Aab/) /\Aab/.match?('abc') 'abc' =~ /\Aab/ /\Aab/ =~ 'abc' 'abc'.match(/\Aab/) /\Aab/.match('abc') # good 'abc'.start_with?('ab')
@example SafeMultiline: true (default)
# good 'abc'.match?(/^ab/) /^ab/.match?('abc') 'abc' =~ /^ab/ /^ab/ =~ 'abc' 'abc'.match(/^ab/) /^ab/.match('abc')
@example SafeMultiline: false
# bad 'abc'.match?(/^ab/) /^ab/.match?('abc') 'abc' =~ /^ab/ /^ab/ =~ 'abc' 'abc'.match(/^ab/) /^ab/.match('abc')
Constants
- MSG
- RESTRICT_ON_SEND
Public Instance Methods
on_send(node)
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# File lib/rubocop/cop/performance/start_with.rb, line 58 def on_send(node) return unless (receiver, regex_str = redundant_regex?(node)) add_offense(node) do |corrector| receiver, regex_str = regex_str, receiver if receiver.is_a?(String) regex_str = drop_start_metacharacter(regex_str) regex_str = interpret_string_escapes(regex_str) new_source = "#{receiver.source}.start_with?(#{to_string_literal(regex_str)})" corrector.replace(node.source_range, new_source) end end
Also aliased as: on_match_with_lvasgn