tests.py

import time
import unittest

from datetime import datetime

import django
import mock

from django import test, http
from django.conf import settings, urls
from django.core.cache import caches
from django.core.urlresolvers import reverse
from django.views.decorators.http import last_modified, etag

from djangocache import cache_page, get_cache_max_age

mocked_response = mock.Mock(side_effect=lambda: http.HttpResponse())


@cache_page(cache_timeout=24 * 60 * 60)
def static(request):
    return mocked_response()


@cache_page(cache_timeout=24 * 60 * 60, cache_min_age=600)
def static2(request):
    return mocked_response()


@cache_page()
def default(request):
    return mocked_response()


def no_cache(request):
    return mocked_response()


@cache_page(cache_timeout=24 * 60 * 60)
# Sun, 17 Jul 2016 09:55:00 GMT
@last_modified(lambda r: datetime.utcfromtimestamp(1468749300))
def cache_with_last_modified(request):
    return mocked_response()


@cache_page(cache_timeout=24 * 60 * 60)
@etag(lambda r: 'etag')
def cache_with_etag(request):
    return mocked_response()


@cache_page(key_prefix=lambda r: dynamic_key_prefix.key_prefix)
def dynamic_key_prefix(request):
    return mocked_response()


@cache_page(cache_timeout=lambda r: dynamic_cache_timeout.cache_timeout)
def dynamic_cache_timeout(request):
    return mocked_response()
dynamic_cache_timeout.cache_timeout = 24 * 60 * 60


class UpdateVaryMiddleware(object):

    def process_response(self, request, response):
        response['Vary'] = 'Header'
        return response

urlpatterns = [
    urls.url(r'static2', static2, name='static2'),
    urls.url(r'static', static, name='static'),
    urls.url(r'default', default, name='default'),
    urls.url(r'no_cache', no_cache, name='no_cache'),
    urls.url(r'dynamic_key_prefix', dynamic_key_prefix, name='dynamic_key_prefix'),
    urls.url(r'dynamic_cache_timeout', dynamic_cache_timeout, name='dynamic_cache_timeout'),
    urls.url(r'cache_with_last_modified$', cache_with_last_modified, name='cache_with_last_modified'),
    urls.url(r'cache_with_etag$', cache_with_etag, name='cache_with_etag'),
]


@test.utils.override_settings(ROOT_URLCONF=__name__)
class CachePageTestCase(test.SimpleTestCase):

    def setUp(self):
        dynamic_key_prefix.key_prefix = 'key_prefix'

    def tearDown(self):
        mocked_response.reset_mock()
        caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()

    def test_default(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(reverse('default'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(reverse('default'))
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            self.assertEqual('300', response['Age'])

    def test_method_post(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.post(reverse('default'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertNotIn('Expires', response)
            self.assertNotIn('Cache-Control', response)
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.post(reverse('default'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertNotIn('Expires', response)
            self.assertNotIn('Cache-Control', response)

    def test_method_head(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.head(reverse('default'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.head(reverse('default'))
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            self.assertEqual('300', response['Age'])

    def test_dynamic_cache_timeout(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(reverse('dynamic_cache_timeout'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(reverse('dynamic_cache_timeout'))
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            self.assertEqual('300', response['Age'])

    def test_dynamic_key_prefix(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(reverse('dynamic_key_prefix'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(reverse('dynamic_key_prefix'))
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            self.assertEqual('300', response['Age'])
            mocked_response.reset_mock()

            response = client.get(
                reverse('dynamic_key_prefix'),
                HTTP_CACHE_CONTROL='max-age=0',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 10:15:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

        dynamic_key_prefix.key_prefix = 'another_key_prefix'

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(reverse('dynamic_key_prefix'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 10:15:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

    @test.utils.override_settings(MIDDLEWARE_CLASSES=[__name__ + '.UpdateVaryMiddleware'])
    def test_with_vary_changed_by_middleware(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('default'),
                HTTP_HEADER='header1',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Vary', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Header', response['Vary'])
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(
                reverse('default'),
                HTTP_HEADER='header1',
            )
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Vary', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Header', response['Vary'])
            self.assertEqual('Sun, 17 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            self.assertEqual('300', response['Age'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(
                reverse('default'),
                HTTP_HEADER='header2',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Vary', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Header', response['Vary'])
            self.assertEqual('Sun, 17 Jul 2016 10:15:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(
                reverse('default'),
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Vary', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Header', response['Vary'])
            self.assertEqual('Sun, 17 Jul 2016 10:15:00 GMT', response['Expires'])
            self.assertEqual('max-age=600', response['Cache-Control'])

    def test_static(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(reverse('static'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(reverse('static'))
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            self.assertEqual('300', response['Age'])

            response = client.get(
                reverse('static'),
                HTTP_CACHE_CONTROL='max-age=0',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:05:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:10:00 GMT
        with mock.patch.object(time, 'time', return_value=1468750200):
            response = client.get(
                reverse('static'),
                HTTP_PRAGMA='no-cache',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:15:00 GMT
        with mock.patch.object(time, 'time', return_value=1468750500):
            response = client.get(
                reverse('static'),
                HTTP_CACHE_CONTROL='max-age=600',
                HTTP_PRAGMA='no-cache',
            )
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Mon, 18 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            self.assertEqual('300', response['Age'])
            mocked_response.reset_mock()

            with test.utils.override_settings(DJANGOCACHE_CACHE_MIN_AGE=600):
                response = client.get(
                    reverse('static'),
                    HTTP_CACHE_CONTROL='max-age=200',
                )
                mocked_response.assert_not_called()
                self.assertNotIn('ETag', response)
                self.assertNotIn('Last-Modified', response)
                self.assertIn('Expires', response)
                self.assertIn('Cache-Control', response)
                self.assertIn('Age', response)
                self.assertEqual('Mon, 18 Jul 2016 10:10:00 GMT', response['Expires'])
                self.assertEqual('max-age=86400', response['Cache-Control'])
                self.assertEqual('300', response['Age'])
                mocked_response.reset_mock()

            response = client.get(
                reverse('static'),
                HTTP_CACHE_CONTROL='max-age=200',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:15:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

            response = client.get(
                reverse('static'),
                HTTP_CACHE_CONTROL='max-age=0',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:15:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])

    def test_static2(self):
        client = test.Client()

        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(reverse('static2'))
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(
                reverse('static2'),
                HTTP_CACHE_CONTROL='max-age=300',
            )
            mocked_response.assert_not_called()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            self.assertEqual('300', response['Age'])
            mocked_response.reset_mock()

        # Sun, 17 Jul 2016 10:10:00 GMT
        with mock.patch.object(time, 'time', return_value=1468750200):
            response = client.get(
                reverse('static'),
                HTTP_CACHE_CONTROL='max-age=300',
            )
            mocked_response.assert_called_once()
            self.assertNotIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Mon, 18 Jul 2016 10:10:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

    def test_with_last_modified(self):
        client = test.Client()

        # conditional request without cache -- not modified
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_last_modified'),
                HTTP_IF_MODIFIED_SINCE='Sun, 17 Jul 2016 09:55:00 GMT',
            )
            mocked_response.assert_not_called()
            self.assertEqual(304, response.status_code)
            self.assertNotIn('ETag', response)
            self.assertIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 09:55:00 GMT', response['Last-Modified'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Request once -- generate cache
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_last_modified'),
            )
            mocked_response.assert_called_once()
            self.assertEqual(200, response.status_code)
            self.assertNotIn('ETag', response)
            self.assertIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 09:55:00 GMT', response['Last-Modified'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # expired request with precondition -- hit cache
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_last_modified'),
                HTTP_IF_MODIFIED_SINCE='Sun, 17 Jul 2016 09:50:00 GMT',
            )
            mocked_response.assert_not_called()
            self.assertEqual(200, response.status_code)
            self.assertNotIn('ETag', response)
            self.assertIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 09:55:00 GMT', response['Last-Modified'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

    @unittest.skipIf(django.VERSION < (1, 9), 'this test works only with Django>=1.9')
    def test_with_last_modified_not_modified(self):
        client = test.Client()

        # Request once -- generate cache
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_last_modified'),
            )
            mocked_response.assert_called_once()
            self.assertEqual(200, response.status_code)
            mocked_response.reset_mock()

        # repeat request with precondition -- hit cache, not modified
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_last_modified'),
                HTTP_IF_MODIFIED_SINCE='Sun, 17 Jul 2016 09:55:00 GMT',
            )
            mocked_response.assert_not_called()
            self.assertEqual(304, response.status_code)
            self.assertNotIn('ETag', response)
            self.assertIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('Sun, 17 Jul 2016 09:55:00 GMT', response['Last-Modified'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

    def test_with_etag(self):
        client = test.Client()

        # conditional request without cache -- not modified
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_etag'),
                HTTP_IF_NONE_MATCH='"etag"',
            )
            mocked_response.assert_not_called()
            self.assertEqual(304, response.status_code)
            self.assertIn('Vary', response)
            self.assertIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('If-None-Match', response['Vary'])
            self.assertEqual('"etag"', response['ETag'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # Request once -- generate cache
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_etag'),
                HTTP_IF_NONE_MATCH='"another_etag"',
            )
            mocked_response.assert_called_once()
            self.assertEqual(200, response.status_code)
            self.assertIn('Vary', response)
            self.assertIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('If-None-Match', response['Vary'])
            self.assertEqual('"etag"', response['ETag'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

        # repeat request with precondition -- hit cache
        # Sun, 17 Jul 2016 10:05:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749900):
            response = client.get(
                reverse('cache_with_etag'),
                HTTP_IF_NONE_MATCH='"another_etag"',
            )
            mocked_response.assert_not_called()
            self.assertEqual(200, response.status_code)
            self.assertIn('Vary', response)
            self.assertIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertIn('Age', response)
            self.assertEqual('If-None-Match', response['Vary'])
            self.assertEqual('"etag"', response['ETag'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            self.assertEqual('300', response['Age'])
            mocked_response.reset_mock()

        # expired request with precondition -- miss cache
        # Sun, 17 Jul 2016 10:00:00 GMT
        with mock.patch.object(time, 'time', return_value=1468749600):
            response = client.get(
                reverse('cache_with_etag'),
                HTTP_IF_NONE_MATCH='"yet_another_etag"',
            )
            mocked_response.assert_called_once()
            self.assertEqual(200, response.status_code)
            self.assertIn('Vary', response)
            self.assertIn('ETag', response)
            self.assertNotIn('Last-Modified', response)
            self.assertIn('Expires', response)
            self.assertIn('Cache-Control', response)
            self.assertEqual('If-None-Match', response['Vary'])
            self.assertEqual('"etag"', response['ETag'])
            self.assertEqual('Mon, 18 Jul 2016 10:00:00 GMT', response['Expires'])
            self.assertEqual('max-age=86400', response['Cache-Control'])
            mocked_response.reset_mock()

    def test_no_cache(self):
        client = test.Client()
        response = client.get(reverse('no_cache'))
        mocked_response.assert_called_once()
        self.assertNotIn('ETag', response)
        self.assertNotIn('Last-Modified', response)
        self.assertNotIn('Expires', response)
        self.assertNotIn('Cache-Control', response)
        mocked_response.reset_mock()

        response = client.get(reverse('no_cache'))
        mocked_response.assert_called_once()
        self.assertNotIn('ETag', response)
        self.assertNotIn('Last-Modified', response)
        self.assertNotIn('Expires', response)
        self.assertNotIn('Cache-Control', response)

    def test_get_cache_max_age_returns_none_on_wrong_or_empty_result(self):
        self.assertIsNone(get_cache_max_age('max-age=a'))
        self.assertIsNone(get_cache_max_age('max-age='))