Can I improve this method with duck print?

Question

I hope I did not understand the meaning of duck printing, but from what I read, it means that I have to write code based on how the object responds to methods and not to type / class.

Here is the code:

def convert_hash(hash)
  if hash.keys.all? { |k| k.is_a?(Integer) }
    return hash
  elsif hash.keys.all? { |k| k.is_a?(Property) }
    new_hash = {}
    hash.each_pair {|k,v| new_hash[k.id] = v}
    return new_hash
  else
    raise "Custom attribute keys should be ID or Property objects"
  end
end

I want to end up with a hash where the keys are an integer representing the identifier of an ActiveRecord object. I don’t particularly like going through hash keys twice with all?to determine if I need to capture the identifier.

Of course, I will accept any other suggestions for improving this code :)

Answer 1

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def convert(hash)
    new_hash = {}
    hash.each_pair { |k,v| new_hash[ k.is_a?(Integer) ? k : k.id ] = v }
    return new_hash
end

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Answer 2

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Answer 3

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h = {}
def h.put obj
  self[obj.id]=obj
end

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h = {}
def h.[]= key, value
  raise "hell" unless key == value.id
  super
end