Testing
-
Create a test to expose the bug
$ python manage.py shell# identify a bug >>> import datetime >>> from django.utils import timezone >>> from polls.models import Question >>> # create a Question instance with pub_date 30 days in the future >>> future_question = Question(pub_date=timezone.now() + datetime.timedelta(days=30)) >>> # was it published recently? >>> future_question.was_published_recently() True# polls/tests.py 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) -
Running tests
$ python manage.py test pollsCreating test database for alias 'default'... System check identified no issues (0 silenced). F ====================================================================== FAIL: test_was_published_recently_with_future_question (polls.tests.QuestionModelTests) ---------------------------------------------------------------------- Traceback (most recent call last): File "/path/to/mysite/polls/tests.py", line 16, in test_was_published_recently_with_future_question self.assertIs(future_question.was_published_recently(), False) AssertionError: True is not False ---------------------------------------------------------------------- Ran 1 test in 0.001s FAILED (failures=1) Destroying test database for alias 'default'... -
Fixing the bug
# polls/models.py def was_published_recently(self): now = timezone.now() return now - datetime.timedelta(days=1) <= self.pub_date <= now# run the test again Creating test database for alias 'default'... System check identified no issues (0 silenced). . ---------------------------------------------------------------------- Ran 1 test in 0.001s OK Destroying test database for alias 'default'... -
More comprehensive tests
# polls/tests.py 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) -
Test a view
# The Django test client $ python manage.py shell>>> from django.test.utils import setup_test_environment >>> setup_test_environment()>>> from django.test import Client >>> # create an instance of the client for our use >>> client = Client()>>> # get a response from '/' >>> response = client.get('/') Not Found: / >>> # we should expect a 404 from that address; if you instead see an >>> # "Invalid HTTP_HOST header" error and a 400 response, you probably >>> # omitted the setup_test_environment() call described earlier. >>> response.status_code 404 >>> # on the other hand we should expect to find something at '/polls/' >>> # we'll use 'reverse()' rather than a hardcoded URL >>> from django.urls import reverse >>> response = client.get(reverse('polls:index')) >>> response.status_code 200 >>> response.content b'\n- \n \n
- What's up? \n \n
]> # Improving our view # polls/views.py class IndexView(generic.ListView): template_name = 'polls/index.html' context_object_name = 'latest_question_list' def get_queryset(self): """Return the last five published questions.""" return Question.objects.order_by('-pub_date')[:5]# polls/views.py from django.utils import timezone# polls/views.py def get_queryset(self): """ Return the last five published questions (not including those set to be published in the future). """ return Question.objects.filter( pub_date__lte=timezone.now() ).order_by('-pub_date')[:5]# Testing our new view # polls/tests.py # from django.urls import reverse# polls/tests.py 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. """ create_question(question_text="Past question.", days=-30) response = self.client.get(reverse('polls:index')) self.assertQuerysetEqual( response.context['latest_question_list'], ['# Testing the DetailView # polls/views.py 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())polls/tests.py 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)