before_phone.rb

class Phone

  def initialize(num)
    @num = num
  end

  def number
   if  @num.gsub!(/[\s+)(-.]/,"")
      return @num
    elsif @num.length == 11 && @num[0] == "1"
      new_num_arr = @num.chars
      new_num_arr.shift
      @num = new_num_arr.join
      return @num
    elsif @num.length == 11 
      return "0000000000"
      # @num.gsub!(/[0-9]/, "0")
      # return @num
    elsif @num.length == 9
      return "0000000000"
    end
      return @num
  end

  def area_code
    @num.chars.first(3).join('')
  end 

  def to_s
    area_code = @num[0..2]
    middle_nums = @num[3..5]
    last_nums = @num[6..9]
    "(#{area_code}) #{middle_nums}-#{last_nums}"
  end
end

phone.rb

class Phone

  def initialize(number)
    @number = number
  end

  def number
    validate( strip_non_numeric(@number) )
  end

  def validate(number)
    if valid_length?(number)
      number
    elsif eleven_start_with_one?(number)
      number[1..-1]
    else
      "0000000000"
    end
  end

  def valid_length?(number)
    number.length == 10
  end

  def eleven_start_with_one?(number)
    number.length == 11 && number.start_with?('1')
  end

  def strip_non_numeric(number)
    number.gsub(/[ .()-]/, '')
  end

  def area_code
    @number[0..2]
  end
  
  def prefix
    @number[3,3]
  end
  
  def line_number
    @number[6,4]
  end

  def to_s
    "(#{area_code}) #{prefix}-#{line_number}"
  end

end

phonetest.rb

require 'minitest/autorun'
require 'minitest/pride'
require_relative './phone'

class PhoneTest < MiniTest::Test

  def test_cleans_number
    number = Phone.new("(123) 456-7890").number
    assert_equal "1234567890", number
  end

  def test_cleans_number_with_dots
    skip
    number = Phone.new("123.456.7890").number
    assert_equal "1234567890", number
  end

  def test_valid_when_11_digits_and_first_is_1
    skip
    number = Phone.new("11234567890").number
    assert_equal "1234567890", number
  end

  def test_invalid_when_11_digits
    skip
    number = Phone.new("21234567890").number
    assert_equal "0000000000", number
  end

  def test_invalid_when_9_digits
    skip
    number = Phone.new("123456789").number
    assert_equal "0000000000", number
  end

  def test_area_code
    skip
    number = Phone.new("1234567890")
    assert_equal "123", number.area_code
  end

  def test_pretty_print
    skip
    number = Phone.new("1234567890")
    assert_equal "(123) 456-7890", number.to_s
  end

end