Question

What I am doing is:

class Foo
  alias_method :__bar__,:bar
  def bar(*arg)
    #do something
    __bar__(*arg)
  end
end

Is it the proper way to do it?

Or it is better to figure out how many required,optional,block arguments the original method has, and write exactly the same amount of arguments?

Answer 1

The use of a slurpy arg is the right approach, but you should also handle any block arguments:

class Foo
  alias_method :__bar__,:bar
  def bar(*arg, &block)
    #do something
    __bar__(*arg, &block)
  end
end