A robot actions code

Robot.rb

class Robot
  MOVEMENTS = ['N', 'E', 'W', 'S']
  ACTIONS = ['G', 'D']

  CRATES_POSITIONS = []

  @length = 10
  @width = 10
  @is_lifting = false

  @current_position = [0,0]

  def execute(movements:)
    movements.each do |i|
      if MOVEMENTS.include?(i)
        send("move_#{i}")
      end

      if ACTIONS.include?(i)
        send("action_#{i}")
      end
    end
  end

  def move_N
    if @current_position[1] == @length
      return
    end

    @current_position[1] += 1
  end

  def move_E
    if @current_position[0] == @width
      return
    end

    @current_position[0] += 1
  end

  def move_W
    if @current_position[0] == 0
      return
    end

    @current_position[0] -= 1
  end

  def move_S
    if @current_position[1] == 0
      return
    end

    @current_position[1] -= 1
  end

  # Action Grab
  def action_G
    if !@is_lifting && crate_present?(@current_position)
      puts ' Robot is already lifting a crate'
      return
    end

    CRATES_POSITIONS.delete(@current_position)
  end

  # Position are the coordinates
  def crate_present?(position)
    return false if CRATES_POSITIONS.include?(position)
    true
  end

  def action_D
    crate_present?(@current_position)
    CRATES_POSITIONS << @current_position
  end
end