Phone Number Formatter

app.rb

require_relative "phone_number_formatter.rb"

# gets input from user
puts "Please enter a phone number: "
phone_number = gets.chomp

# creates a new instance of the PhoneNumberFormatter class
phone_number = PhoneNumberFormatter.new(phone_number)

# output string, phone number with correct format
puts phone_number.format

phone_number_formatter.rb

class PhoneNumberFormatter
  attr_accessor :phone_number
  
  # initialize method
  #
  # phone_number - data type
  #
  # returns self
  def initialize(phone_number)
    @phone_number = phone_number
  end
  
  # formats phone number entered by user
  #
  # returns string
  def format
    if phone_number.length < 12
      phone_number.insert(3, "-")
      phone_number.insert(7, "-")
    end
  end
  
end

phone_number_formatter_test.rb

require "minitest/autorun"
require_relative "phone_number_formatter.rb"

class PhoneNumberFormatterTest < Minitest::Test
  # when I run the format method,
  # I expect it to change a phone number 1234567890 
  # and return a phone number formatted 123-456-7890
  
  def test_formatting_phone_number
    phone_number = PhoneNumberFormatter.new("1234567890")
    assert_equal("123-456-7890", phone_number.format)
  end
end