Exercism Ruby - Robot Name

README.md

Robot Name

Write a program that manages robot factory settings.

When robots come off the factory floor, they have no name.

The first time you boot them up, a random name is generated, such as RX837 or BC811.

Every once in a while we need to reset a robot to its factory settings, which means that their name gets wiped. The next time you ask, it gets a new name.

For bonus points

Did you get the tests passing and the code clean? If you want to, these are some additional things you could try:

• Random names means a risk of collisions. Make sure the same name is never used twice. Feel free to introduce additional tests.

Then please share your thoughts in a comment on the submission. Did this experiment make the code better? Worse? Did you learn anything from it?

Source

A debugging session with Paul Blackwell at gSchool. view source

robot.rb

class Robot
  attr_accessor :name

  CHARACTERS = ('A'..'Z').to_a
  DIGITS = ('0'..'9').to_a

  def initialize
    @name = generate_name
  end

  def reset
    @name = generate_name
  end

  private

  def generate_name
    "#{random_letter_sequence(2)}#{random_number_sequence(3)}"
  end

  def random_letter_sequence(number_of_characters)
    number_of_characters.times.inject('') { |string, iteration| string << CHARACTERS.sample }
  end

  def random_number_sequence(number_of_digits)
    number_of_digits.times.inject('') { |string, iteration| string << DIGITS.sample }
  end
end

robot_name_test.rb

require 'minitest/autorun'
require_relative 'robot'

class RobotTest < MiniTest::Unit::TestCase
  def test_has_name
    # rubocop:disable Lint/AmbiguousRegexpLiteral
    assert_match /^[A-Z]{2}\d{3}$/, Robot.new.name
    # rubocop:enable Lint/AmbiguousRegexpLiteral
  end

  def test_name_sticks
    robot = Robot.new
    robot.name
    assert_equal robot.name, robot.name
  end

  def test_different_robots_have_different_names
    # rubocop:disable Lint/UselessComparison
    assert Robot.new.name != Robot.new.name
    # rubocop:enable Lint/UselessComparison
  end

  def test_reset_name
    robot = Robot.new
    name = robot.name
    robot.reset
    name2 = robot.name
    assert name != name2
    # rubocop:disable Lint/AmbiguousRegexpLiteral
    assert_match /^[A-Z]{2}\d{3}$/, name2
    # rubocop:enable Lint/AmbiguousRegexpLiteral
  end
end