valueobject.rb

point.rb

class Point
  attr_reader :x, :y
  
  def self.clone_from(point, x: nil, y: nil)
    new(x || point.x, y || point.y)
  end
  
  def initialize(x=0, y=0)
    @x = x
    @y = y
  end
end

first_point = Point.new(x: 1, y: 2)
second_point = Point.clone_from(first_point, y: 3)

test.rb

class ValueObject
  attr_reader :attribute1, :attribute2
  
  def self.clone_from(obj, attribute1: nil, attribute2: nil)
    new(attribute1 || obj.attribute1, attribute2 || obj.attribute2)
  end
  
  def initialize(attribute1, attribute2)
    @attribute1 = attribute1
    @attribute2 = attribute2
  end
end

a = ValueObject.new(1, 2)
b = ValueObject.clone_from(a, attribute2: 3)