Django 入门学习总结6 - 测试

1、介绍自动化测试

测试的主要工作是检查代码的运行情况。测试有全覆盖和部分覆盖。

自动测试表示测试工作由系统自动完成。

在大型系统中，有许多组件有很复杂的交互。一个小的变化可能会带来意想不到的后果

测试能发现问题，并以此解决问题。

测试驱动开发

在polls/tests.py文件中，建立 测试方法：

import datetime

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

from .models import Question

class QuestionModelTests(TestCase):
    def test_was_published_recently_with_future_question(self):
        """
        was_published_recently() returns False for questions whose pub_date
        is in the future.
        """
        time = timezone.now() + datetime.timedelta(days=30)
        future_question = Question(pub_date=time)
        self.assertIs(future_question.was_published_recently(), False)

在终端中输入以下命令，对投票系统进行测试：

python manage.py test polls

则输出以下信息。

表明系统有bug，测试失败。

修改文件polls/models.py为：

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

重新测试，则bug消失。

更复杂的测试

在测试文件中输入更多的测试方法：

def test_was_published_recently_with_old_question(self):
        """
        was_published_recently() returns False for questions whose pub_date
        is older than 1 day.
        """
        time = timezone.now() - datetime.timedelta(days=1, seconds=1)
        old_question = Question(pub_date=time)
        self.assertIs(old_question.was_published_recently(), False)

    def test_was_published_recently_with_recent_question(self):
        """
        was_published_recently() returns True for questions whose pub_date
        is within the last day.
        """
        time = timezone.now() - datetime.timedelta(hours=23, minutes=59, seconds=59)
        recent_question = Question(pub_date=time)
        self.assertIs(recent_question.was_published_recently(), True)

现在有三个测试方法，分别对应于过去、最近和未来的问题。

可以在客户端建立测试环境来对网页进行测试。

在命令提示符下输入：

python manage.py shell

from django.test.utils import setup_test_environment

setup_test_environment()

导入客户端

from django.test import Client

建立一个客户端实例对象

client = Client()

修改polls/tests.py文件：

from django.urls import reverse

添加以下内容：

def create_question(question_text, days):
        """
        Create a question with the given `question_text` and published the
        given number of `days` offset to now (negative for questions published
        in the past, positive for questions that have yet to be published).
        """
        time = timezone.now() + datetime.timedelta(days=days)
        return Question.objects.create(question_text=question_text, pub_date=time)

    class QuestionIndexViewTests(TestCase):
        def test_no_questions(self):
            """
            If no questions exist, an appropriate message is 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_question_list"], [])

        def test_past_question(self):
            """
            Questions with a pub_date in the past are displayed on the
            index page.
            """
            question = create_question(question_text="Past question.", days=-30)
            response = self.client.get(reverse("polls:index"))
            self.assertQuerySetEqual(
                response.context["latest_question_list"],
                [question],
            )

        def test_future_question(self):
            """
            Questions with a pub_date in the future aren't displayed on
            the index page.
            """
            create_question(question_text="Future question.", days=30)
            response = self.client.get(reverse("polls:index"))
            self.assertContains(response, "No polls are available.")
            self.assertQuerySetEqual(response.context["latest_question_list"], [])

        def test_future_question_and_past_question(self):
            """
            Even if both past and future questions exist, only past questions
            are displayed.
            """
            question = create_question(question_text="Past question.", days=-30)
            create_question(question_text="Future question.", days=30)
            response = self.client.get(reverse("polls:index"))
            self.assertQuerySetEqual(
                response.context["latest_question_list"],
                [question],
            )

        def test_two_past_questions(self):
            """
            The questions index page may display multiple questions.
            """
            question1 = create_question(question_text="Past question 1.", days=-30)
            question2 = create_question(question_text="Past question 2.", days=-5)
            response = self.client.get(reverse("polls:index"))
            self.assertQuerySetEqual(
                response.context["latest_question_list"],
                [question2, question1],
            )

在polls/views.py中，添加以下内容：

class DetailView(generic.DetailView):
        ...

        def get_queryset(self):
            """
            Excludes any questions that aren't published yet.
            """
            return Question.objects.filter(pub_date__lte=timezone.now())

在polls/tests.py中，添加以下的内容：

class QuestionDetailViewTests(TestCase):
        def test_future_question(self):
            """
            The detail view of a question with a pub_date in the future
            returns a 404 not found.
            """
            future_question = create_question(question_text="Future question.", days=5)
            url = reverse("polls:detail", args=(future_question.id,))
            response = self.client.get(url)
            self.assertEqual(response.status_code, 404)

        def test_past_question(self):
            """
            The detail view of a question with a pub_date in the past
            displays the question's text.
            """
            past_question = create_question(question_text="Past Question.", days=-5)
            url = reverse("polls:detail", args=(past_question.id,))
            response = self.client.get(url)
            self.assertContains(response, past_question.question_text)

错误更改：如果使用self.assertQuerySetEqual 收到一条错误消息“DeviceTest object has no attribute assertQuerySetEqual”

应将assertQuerySetEqual  替换为：assertEqual