#011_重构用户名 PART2

接着010里面的例子，让我们先写User类的单元测试吧

require File.dirname(__FILE__) + '/../test_helper'

class UserTest < Test::Unit::TestCase
  fixtures :users
  
  def test_full_name_without_middle_initial
    user = User.new(:first_name => 'John', :last_name => 'Doe')
    assert_equal 'John Doe', user.full_name
  end
  
  def test_full_name_with_middle_initial
    user = User.new(:first_name => 'John', :middle_initial => 'H', :last_name => 'Doe')
    assert_equal 'John H. Doe', user.full_name  
  end
  
  def test_full_name_with_blank_middle_initial
    user = User.new(:first_name => 'John', :middle_initial => '', :last_name => 'Doe')
    assert_equal 'John Doe', user.full_name
  end
end

运行测试，很遗憾，第3个测试用例没能通过。

class User < ActiveRecord::Base      
  def full_name      
    name = first_name + " "   
    name += "#{middle_initial}. " unless middle_initial.nil?      
    name += last_name      
    name      
  end      
end

虽然很好改，但我们决定继续重构一下

class User < ActiveRecord::Base
  def full_name
    [first_name, middle_initial_with_period, last_name].compact.join(' ')
  end
  
  def middle_initial_with_period
    "#{middle_initial}." unless middle_initial.blank?
  end
end

因为加上了blank?这个方法，因此测试通过。
另外一个考虑是first_name与last_name是否为空，其实我真不是很懂。。

[first_name, middle_initial_with_period, last_name].reject{ |i| i.blank? }.compact.join(' ')
[first_name, middle_initial_with_period, last_name].reject(&:blank?) * ' '