prepend

prepend.rb

class Wheel
  def tire
    puts "Tire is flat, needs service"
  end
end

Wheel.new.tire
# Tire is flat, needs service

module SpareTire
  def tire
    puts "Tire is on perfect working condtions"
  end
end

Wheel.prepend(SpareTire).new.tire
# Tire is on perfect working condtions

# Prepend adds SpareTire to the beginning of
# Wheel's ancestors

Wheel.ancestors
# => [SpareTire, Wheel, Object, PP::ObjectMixin, Kernel, BasicObject]
# This means you override that method

# It can also be used to add Telemetry data to custom code you don't own 😌

module TireTelemetry
  def tire
    puts "Here I started"
    super # This will call the previous "tire" method
	puts "Here I finished"
  end
end

Wheel.prepend(TireTelemetry).new.tire
# Here I started
# Tire is on perfect working condtions
# Here I finished ✨