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rubymonkeypatching

Monkey-patching ruby method with bang

Is it possible to monkey-patch a method with a bang at the end?

I want to monkey-patch String.upcase!, but I don't know how to achieve that.

The problem is that I want to change the original string object.

Here's an example:

class String
  def upcase!
    self.mb_chars.upcase.to_s
  end
end

Now if I type that in console and try it out, it doesn't work:

[1] pry(main)> asd="asd"
=> "asd"
[2] pry(main)> asd.upcase
=> "ASD"
[3] pry(main)> asd
=> "asd"
[4] pry(main)> asd.upcase!
=> "ASD"
[5] pry(main)> asd
=> "asd"
Solution

  • Your issue is independent of the method having a bang. If you want to replace the receiver string, use the method String#replace.

    class String
  def foo
    replace(whatever_string_you_want_to_replace_the_receiver_with)
  end
end

    You can perhaps put mb_chars.upcase as the argument to replace.