在重构实战2和重构实战1里,我们讨论了与重构、测试有关的话题。截止上一篇结束时,完成了对User
类的重构,但是测试用例代码还有些乱。让我们看看如何清理一下。
require 'test_helper' class UserTest < ActiveSupport::TestCase test "full name without middle initial" do user = User.new(:first_name => "John", :last_name => "Smith") assert_equal 'John Smith', user.full_name end test "full name with middle initial" do user = User.new(:first_name => "Paul", :middle_initial => "P", :last_name => "Hughes") assert_equal 'Paul P. Hughes', user.full_name end test "full name with empty middle initial" do user = User.new(:first_name => "John", :middle_initial => "", :last_name => "Jones") assert_equal 'John Jones', user.full_name end end
User
类的测试用例代码。
现在这三个用例,有大量的冗余代码。都是分别创建一个User
的对象,然后比较full_name
方法的返回值与我们的期待值是否一致。应该创建一个方法,帮我们完成创建对象及返回full_name
的结果。
def full_name(first, middle, last) User.new(:first_name => first, :middle_initial => middle, :last_name => last).full_name end
UserTest
类中的辅助方法。
这样一来,测试用例代码可以被精简为下面的样子:
test "full name without middle initial" do assert_equal "John Smith", full_name('John', nil, 'Smith') end test "full name with middle initial" do assert_equal 'Paul P. Hughes', full_name('Paul', 'P', 'Hughes') end test "full name with empty middle initial" do assert_equal "John Jones", full_name('John', '', 'Jones') end
简化后的测试代码。
运行之后,所有的用例依然能够通过。
Laa-Laa:ep11 eifion$ autotest loading autotest/rails /opt/local/bin/ruby -I.:lib:test -rtest/unit -e "%w[test/unit/user_test.rb test/functional/users_controller_test.rb].each { |f| require f }" | unit_diff -u Loaded suite -e Started ... Finished in 0.282538 seconds. 3 tests, 3 assertions, 0 failures, 0 errors
输出显示用例执行通过。
测试代码变得简单多了,可以把他们移动到一个用例中。但这么做同时带来了一个新的问题,如果某一个测试条件没有满足,怎样识别出来呢?可以再assert_equal
方法中多传入一个字符串,测试不通过时会打印出来以便定位。
require 'test_helper' class UserTest < ActiveSupport::TestCase test "full name" do assert_equal "John Smith", full_name('John', nil, 'Smith'), 'nil middle initial' assert_equal 'Paul P. Hughes', full_name('Paul', 'P', 'Hughes'), 'P middle initial' assert_equal "John Jones", full_name('John', '', 'Jones'), 'blank middle initial' end def full_name(first, middle, last) User.new(:first_name => first, :middle_initial => middle, :last_name => last).full_name end end
重构后的UserTest
代码
这三篇文章,我们对代码和测试用例都分别进行了重构,代码的可读性和可维护性都得到了提升。好啦!希望这个小例子能让你感受到进行重构和使用测试用例的益处吧!
作者授权:Your welcome to post the translated text on your blog as well if the episode is free(not Pro). I just ask that you post a link back to the original episode on railscasts.com.
原文链接:http://railscasts.com/episodes/12-refactoring-user-name-part-3