Ruby: Formatting phone numbers (naive)

ruby_phone_format

# Download this file:
# https://gist.github.com/scottcreynolds/ac1b5c8d96de0c91bf7c/download

# Run it from your terminal with:
# ruby ruby_phone_format.rb
# (Just make sure you are in the right directory)

# ======================================
# Ignore All This Code
# ======================================

@tests = 0

def test(title, &b)
  @tests += 1
  begin
    if b
      result = b.call
      if result.is_a?(Array) 
        puts "#{@tests}. fail: #{title}"
        puts "      expected #{result.first} to equal #{result.last}"
      elsif result
        puts "#{@tests}. pass: #{title}"
      else
        puts "#{@tests}. fail: #{title}"
      end
    else
      puts "#{@tests}. pending: #{title}"
    end
  rescue => e
    puts "fail: #{title}"
    puts e
  end
end

def assert(statement)
  !!statement
end

def assert_equal(actual, expected)
  if expected == actual
    true
  else
    [expected, actual]
  end
end

class Object
  def __
    puts "__ should be replaced with a value or expression to make the test pass."
    false
  end
end

# ======================================
# Start Here - Make these tests pass.
# ======================================

# Define a method named normalize_phone_number that takes one
# string argument and returns a string in the format
# (XXX) XXX-XXXX if possible, and just returns the input string if not

# Method definition goes here:
def normalize_phone_number(number)
  numbers = []

  number.each_char do |char|
    if "0123456789".include?(char)
      numbers << char
    end
  end
  if numbers.length < 10
    number
  else
    "(" + numbers[0,3].join + ") " + numbers[3,3].join + "-" + numbers[6,4].join
  end
end

def normalize_phone_number(number)
  numbers = number.scan(/\d/)
  if numbers.length < 10
    number
  else
    sprintf "(%3s) %3s-%4s", numbers[0,3].join, numbers[3,3].join, numbers[6,4].join
  end
end

# 1.
test 'that "1234567890" gets formatted' do

  assert_equal normalize_phone_number("1234567890"), "(123) 456-7890"
end

# 2.
test 'that "(123)4567890" gets formatted' do

  assert_equal normalize_phone_number("(123)4567890"), "(123) 456-7890"
end

# 3.
test 'that "123 456 7890" gets formatted' do

  assert_equal normalize_phone_number("123 456 7890"), "(123) 456-7890"
end

# 4.
test 'that "123-4567890" gets formatted' do

  assert_equal normalize_phone_number("123-4567890"), "(123) 456-7890"
end

# 5.
test 'that "123-456-7890" gets formatted' do

  assert_equal normalize_phone_number("123-456-7890"), "(123) 456-7890"
end

# 6.
test 'that "123ABF90" does not get formatted' do

  assert_equal normalize_phone_number("123ABF90"), "123ABF90"
end