Django初级手册5-自动化测试

什么是自动化测试

1. 每次更新完系统后，可自动进行测试，而不是手工从头测试一遍；
2. 从长远和全局的角度看，测试能节约我们的时间；
3. 测试是一种积极的行为，它能预防问题，而不仅仅是识别问题；
4. 测试有助于代码美观和团队合作；
5. 测试能使你详细你的代码，没有测试的代码存在设计漏洞；
6. 测试可以边编写边执行，也可以测试为驱动，或者最后进行测试；

model部分的测试

tests.py文件

import datetime

from django.utils import timezone
from django.test import TestCase

from polls.models import Poll

class PollMethodTests(TestCase):

    def test_was_published_recently_with_future_poll(self):
        """
        was_published_recently() should return False for polls whose
        pub_date is in the future
        """
        future_poll = Poll(pub_date=timezone.now() + datetime.timedelta(days=30))
        self.assertEqual(future_poll.was_published_recently(), False)

运行命令

python manage.py test polls

流程如下：

1. 首先寻找polls应用下的tests
2. 找到了django.test.TestCase的子类
3. 创建了以测试为目的的数据库
4. 寻找测试的方法——以test开头的方法
5. 在方法中，创建了一个Poll的对象
6. 用断言的方法返回结果

修正BUG

def was_published_recently(self):
    now = timezone.now()
    return now - datetime.timedelta(days=1) <= self.pub_date <  now

完整的测试

def test_was_published_recently_with_old_poll(self):
    """
    was_published_recently() should return False for polls whose pub_date
    is older than 1 day
    """
    old_poll = Poll(pub_date=timezone.now() - datetime.timedelta(days=30))
    self.assertEqual(old_poll.was_published_recently(), False)

def test_was_published_recently_with_recent_poll(self):
    """
    was_published_recently() should return True for polls whose pub_date
    is within the last day
    """
    recent_poll = Poll(pub_date=timezone.now() - datetime.timedelta(hours=1))
    self.assertEqual(recent_poll.was_published_recently(), True)

视图层的测试

Django测试client

此过程不会创建测试数据库，因此会修改原有数据库

>>> from django.test.utils import setup_test_environment
>>> setup_test_environment()
>>> from django.test.client import Client
>>> client = Client()
>>> response = client.get('/')
>>> from django.core.urlresolvers import reverse
>>> response = client.get(reverse('polls:index'))
>>> response.status_code
>>> response.content

修正view并测试

不显示未来发表的投票

from django.utils import timezone
def get_queryset(self):
    """
    Return the last five published polls (not including those set to be
    published in the future).
    """
    return Poll.objects.filter(
        pub_date__lte=timezone.now()
    ).order_by('-pub_date')[:5]

进行测试

from django.core.urlresolvers import reverse
def create_poll(question, days):
    """
    Creates a poll with the given `question` published the given number of
    `days` offset to now (negative for polls published in the past,
    positive for polls that have yet to be published).
    """
    return Poll.objects.create(question=question,
        pub_date=timezone.now() + datetime.timedelta(days=days))

class PollViewTests(TestCase):
    def test_index_view_with_no_polls(self):
        """
        If no polls exist, an appropriate message should be displayed.
        """
        response = self.client.get(reverse('polls:index'))
        self.assertEqual(response.status_code, 200)
        self.assertContains(response, "No polls are available.")
        self.assertQuerysetEqual(response.context['latest_poll_list'], [])

    def test_index_view_with_a_past_poll(self):
        """
        Polls with a pub_date in the past should be displayed on the index page.
        """
        create_poll(question="Past poll.", days=-30)
        response = self.client.get(reverse('polls:index'))
        self.assertQuerysetEqual(
            response.context['latest_poll_list'],
            ['<Poll: Past poll.>']
        )

    def test_index_view_with_a_future_poll(self):
        """
        Polls with a pub_date in the future should not be displayed on the
        index page.
        """
        create_poll(question="Future poll.", days=30)
        response = self.client.get(reverse('polls:index'))
        self.assertContains(response, "No polls are available.", status_code=200)
        self.assertQuerysetEqual(response.context['latest_poll_list'], [])

    def test_index_view_with_future_poll_and_past_poll(self):
        """
        Even if both past and future polls exist, only past polls should be
        displayed.
        """
        create_poll(question="Past poll.", days=-30)
        create_poll(question="Future poll.", days=30)
        response = self.client.get(reverse('polls:index'))
        self.assertQuerysetEqual(
            response.context['latest_poll_list'],
            ['<Poll: Past poll.>']
        )

    def test_index_view_with_two_past_polls(self):
        """
        The polls index page may display multiple polls.
        """
        create_poll(question="Past poll 1.", days=-30)
        create_poll(question="Past poll 2.", days=-5)
        response = self.client.get(reverse('polls:index'))
        self.assertQuerysetEqual(
            response.context['latest_poll_list'],
             ['<Poll: Past poll 2.>', '<Poll: Past poll 1.>']
        )

1. create_poll是为了减少代码冗余；
2. assertEqual判断变量相等，assertQuerysetEqual判断列表等集合相等；
3. assertContains(response, "No polls are available.")判断返回值，也可增加self.assertContains(response, "No polls are available.", status_code=200)；

测试DetailView

为了避免直接通过URL访问未来的测试，我们修改view.py中的相应页面；

class DetailView(generic.DetailView):
    ...
    def get_queryset(self):
        """
        Excludes any polls that aren't published yet.
        """
        return Poll.objects.filter(pub_date__lte=timezone.now())

增加相应的测试页面

class PollIndexDetailTests(TestCase):
    def test_detail_view_with_a_future_poll(self):
        """
        The detail view of a poll with a pub_date in the future should
        return a 404 not found.
        """
        future_poll = create_poll(question='Future poll.', days=5)
        response = self.client.get(reverse('polls:detail', args=(future_poll.id,)))
        self.assertEqual(response.status_code, 404)

    def test_detail_view_with_a_past_poll(self):
        """
        The detail view of a poll with a pub_date in the past should display
        the poll's question.
        """
        past_poll = create_poll(question='Past Poll.', days=-5)
        response = self.client.get(reverse('polls:detail', args=(past_poll.id,)))
        self.assertContains(response, past_poll.question, status_code=200)

未来测试的建议

1. 不要怕测试多，测试越多越好；
2. 每个model or view，都有独立的TestClass；
3. 每个测试方法，都有一个你想要测试的独立环境；
4. 测试方法的名字要描述他们的功能；