class RuboCop::Cop::Performance::DeleteSuffix
In Ruby 2.5, `String#delete_suffix` has been added.
This cop identifies places where `gsub(/suffixz/, '')` and `sub(/suffixz/, '')` can be replaced by `delete_suffix('suffix')`. It is marked as unsafe by default because `Pathname` has `sub` but not `delete_suffix`.
This cop has `SafeMultiline` configuration option that `true` by default because `suffix$` is unsafe as it will behave incompatible with `delete_suffix?` for receiver is multiline string.
The `delete_suffix('suffix')` method is faster than `gsub(/suffixz/, '')`.
@example
# bad str.gsub(/suffix\z/, '') str.gsub!(/suffix\z/, '') str.sub(/suffix\z/, '') str.sub!(/suffix\z/, '') # good str.delete_suffix('suffix') str.delete_suffix!('suffix')
@example SafeMultiline: true (default)
# good str.gsub(/suffix$/, '') str.gsub!(/suffix$/, '') str.sub(/suffix$/, '') str.sub!(/suffix$/, '')
@example SafeMultiline: false
# bad str.gsub(/suffix$/, '') str.gsub!(/suffix$/, '') str.sub(/suffix$/, '') str.sub!(/suffix$/, '')
Constants
- MSG
- PREFERRED_METHODS
- RESTRICT_ON_SEND
Public Instance Methods
on_send(node)
click to toggle source
# File lib/rubocop/cop/performance/delete_suffix.rb, line 68 def on_send(node) return unless (receiver, bad_method, regexp_str, replace_string = delete_suffix_candidate?(node)) return unless replace_string.empty? good_method = PREFERRED_METHODS[bad_method] message = format(MSG, current: bad_method, prefer: good_method) add_offense(node.loc.selector, message: message) do |corrector| regexp_str = drop_end_metacharacter(regexp_str) regexp_str = interpret_string_escapes(regexp_str) string_literal = to_string_literal(regexp_str) new_code = "#{receiver.source}.#{good_method}(#{string_literal})" corrector.replace(node, new_code) end end