class RuboCop::Cop::Performance::UnfreezeString

In Ruby 2.3 or later, use unary plus operator to unfreeze a string literal instead of `String#dup` and `String.new`. Unary plus operator is faster than `String#dup`.

Note: `String.new` (without operator) is not exactly the same as `+''`. These differ in encoding. `String.new.encoding` is always `ASCII-8BIT`. However, `(+'').encoding` is the same as script encoding(e.g. `UTF-8`). So, if you expect `ASCII-8BIT` encoding, disable this cop.

@example

# bad
''.dup
"something".dup
String.new
String.new('')
String.new('something')

# good
+'something'
+''

Constants

MSG

Public Instance Methods

on_send(node) click to toggle source
# File lib/rubocop/cop/performance/unfreeze_string.rb, line 44
def on_send(node)
  add_offense(node) if dup_string?(node) || string_new?(node)
end