My Basic Unit Test

My Model

class Phone < ActiveRecord::Base
    belongs_to :phonable, :polymorphic=>true
    acts_as_audited
    validates_presence_of :number
    before_validation :parse_phone
    
    def parse_phone
      if self && self.number !=nil
          number = self.number.gsub(/\D/,"")
          if number.length == 10
            self.area_code=number.match(/\d{3}/).to_s
            self.number = number.match(/\d{7}$/).to_s
          elsif number.length == 11
            self.country_code=number.match(/\d{1}/).to_s
            self.area_code=number.match(/(?<=\d)\d{3}/).to_s
            self.number = number.match(/\d{7}$/).to_s
          elsif number.length == 14
            self.country_code=number.match(/\d{4}/).to_s
            self.area_code=number.match(/(?<=\d{4})\d{3}/).to_s
            self.number = number.match(/\d{7}$/).to_s
          else
            self.number=number
          end
        end
    end
    
end

My Unit Test

require 'test_helper'

class PhoneTest < ActiveSupport::TestCase
  test "invalid with empty attributes" do
    phone = Phone.new
    assert !phone.valid?
    assert phone.errors[:number].any?
  end
  
  test "phone number 7 digits" do
    phone = Phone.new
    phone.number="123-1234"
    phone.valid?
    assert !phone.errors[:number].any?
    assert (phone.area_code == nil)
  end
  test "phone number 10 digits" do
    phone = Phone.new
    phone.number="123-123-1234"
    phone.valid?
    assert !phone.errors[:number].any?
    assert !phone.errors[:area_code].any?
    assert (phone.area_code != nil && phone.area_code.length == 3)
  end
  test "phone number 11 digits" do
    phone = Phone.new
    phone.number="1-123-123-1234"
    phone.valid?
    assert !phone.errors[:number].any?
    assert !phone.errors[:area_code].any?
    assert !phone.errors[:country_code].any?
    assert (phone.area_code !=nil && phone.area_code.length == 3 && phone.country_code != nil && phone.country_code.length ==1)
  end
  test "phone number 14 digits" do
    phone = Phone.new
    phone.number="1-123-123-123-1234"
    phone.valid?
    assert !phone.errors[:number].any?
    assert !phone.errors[:area_code].any?
    assert !phone.errors[:country_code].any?
    assert (phone.area_code !=nil && phone.area_code.length == 3 && phone.country_code != nil && phone.country_code.length ==4)
  end
  
  test "phone number non numeric" do
    phone = Phone.new
    phone.number="abcdefghijklmnopqrstuvwxyz"
    assert !phone.valid?
  end
  
end