class RubbyCop::Cop::Performance::StartWith
This cop identifies unnecessary use of a regex where `String#start_with?` would suffice.
@example
@bad 'abc' =~ /\Aab/ 'abc'.match(/\Aab/) @good 'abc'.start_with?('ab')
Constants
- MSG
- SINGLE_QUOTE
Public Instance Methods
autocorrect(node)
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# File lib/rubbycop/cop/performance/start_with.rb, line 42 def autocorrect(node) redundant_regex?(node) do |receiver, regex_str| receiver, regex_str = regex_str, receiver if receiver.is_a?(String) regex_str = regex_str[2..-1] # drop \A anchor regex_str = interpret_string_escapes(regex_str) lambda do |corrector| new_source = receiver.source + '.start_with?(' + to_string_literal(regex_str) + ')' corrector.replace(node.source_range, new_source) end end end
literal_at_start?(regex_str)
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# File lib/rubbycop/cop/performance/start_with.rb, line 26 def literal_at_start?(regex_str) # is this regexp 'literal' in the sense of only matching literal # chars, rather than using metachars like . and * and so on? # also, is it anchored at the start of the string? # (tricky: \s, \d, and so on are metacharacters, but other characters # escaped with a slash are just literals. LITERAL_REGEX takes all # that into account.) regex_str =~ /\A\\A(?:#{LITERAL_REGEX})+\z/ end
on_send(node)
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# File lib/rubbycop/cop/performance/start_with.rb, line 36 def on_send(node) return unless redundant_regex?(node) add_offense(node, :expression) end