django/tests/urlpatterns_reverse/tests.py

"""
Unit tests for reverse URL lookups.
"""
import sys
import threading

from admin_scripts.tests import AdminScriptTestCase

from django.conf import settings
from django.conf.urls import include, url
from django.contrib.auth.models import User
from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
from django.http import (
    HttpRequest, HttpResponsePermanentRedirect, HttpResponseRedirect,
)
from django.shortcuts import redirect
from django.test import SimpleTestCase, TestCase, override_settings
from django.test.utils import override_script_prefix
from django.urls import (
    NoReverseMatch, Resolver404, ResolverMatch, URLPattern, URLResolver,
    get_callable, get_resolver, resolve, reverse, reverse_lazy,
)
from django.urls.resolvers import RegexPattern

from . import middleware, urlconf_outer, views
from .utils import URLObject
from .views import empty_view

resolve_test_data = (
    # These entries are in the format: (path, url_name, app_name, namespace, view_name, func, args, kwargs)
    # Simple case
    ('/normal/42/37/', 'normal-view', '', '', 'normal-view', views.empty_view, (), {'arg1': '42', 'arg2': '37'}),
    (
        '/view_class/42/37/', 'view-class', '', '', 'view-class', views.view_class_instance, (),
        {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/included/normal/42/37/', 'inc-normal-view', 'included_namespace_urls',
        'included_namespace_urls', 'included_namespace_urls:inc-normal-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/included/view_class/42/37/', 'inc-view-class', 'included_namespace_urls',
        'included_namespace_urls', 'included_namespace_urls:inc-view-class',
        views.view_class_instance, (), {'arg1': '42', 'arg2': '37'}
    ),

    # Unnamed args are dropped if you have *any* kwargs in a pattern
    ('/mixed_args/42/37/', 'mixed-args', '', '', 'mixed-args', views.empty_view, (), {'arg2': '37'}),
    (
        '/included/mixed_args/42/37/', 'inc-mixed-args', 'included_namespace_urls',
        'included_namespace_urls', 'included_namespace_urls:inc-mixed-args',
        views.empty_view, (), {'arg2': '37'}
    ),
    (
        '/included/12/mixed_args/42/37/', 'inc-mixed-args', 'included_namespace_urls',
        'included_namespace_urls', 'included_namespace_urls:inc-mixed-args',
        views.empty_view, (), {'arg2': '37'}
    ),

    # Unnamed views should have None as the url_name. Regression data for #21157.
    (
        '/unnamed/normal/42/37/', None, '', '', 'urlpatterns_reverse.views.empty_view', views.empty_view, (),
        {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/unnamed/view_class/42/37/', None, '', '', 'urlpatterns_reverse.views.ViewClass', views.view_class_instance,
        (), {'arg1': '42', 'arg2': '37'}
    ),

    # If you have no kwargs, you get an args list.
    ('/no_kwargs/42/37/', 'no-kwargs', '', '', 'no-kwargs', views.empty_view, ('42', '37'), {}),
    (
        '/included/no_kwargs/42/37/', 'inc-no-kwargs', 'included_namespace_urls',
        'included_namespace_urls', 'included_namespace_urls:inc-no-kwargs',
        views.empty_view, ('42', '37'), {}
    ),
    (
        '/included/12/no_kwargs/42/37/', 'inc-no-kwargs', 'included_namespace_urls',
        'included_namespace_urls', 'included_namespace_urls:inc-no-kwargs',
        views.empty_view, ('12', '42', '37'), {}
    ),

    # Namespaces
    (
        '/test1/inner/42/37/', 'urlobject-view', 'testapp', 'test-ns1', 'test-ns1:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/included/test3/inner/42/37/', 'urlobject-view', 'included_namespace_urls:testapp',
        'included_namespace_urls:test-ns3', 'included_namespace_urls:test-ns3:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/ns-included1/normal/42/37/', 'inc-normal-view', 'included_namespace_urls',
        'inc-ns1', 'inc-ns1:inc-normal-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/included/test3/inner/42/37/', 'urlobject-view', 'included_namespace_urls:testapp',
        'included_namespace_urls:test-ns3', 'included_namespace_urls:test-ns3:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/default/inner/42/37/', 'urlobject-view', 'testapp', 'testapp', 'testapp:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/other2/inner/42/37/', 'urlobject-view', 'nodefault', 'other-ns2', 'other-ns2:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/other1/inner/42/37/', 'urlobject-view', 'nodefault', 'other-ns1', 'other-ns1:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),

    # Nested namespaces
    (
        '/ns-included1/test3/inner/42/37/', 'urlobject-view', 'included_namespace_urls:testapp',
        'inc-ns1:test-ns3', 'inc-ns1:test-ns3:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/ns-included1/ns-included4/ns-included2/test3/inner/42/37/', 'urlobject-view',
        'included_namespace_urls:namespace_urls:included_namespace_urls:testapp',
        'inc-ns1:inc-ns4:inc-ns2:test-ns3',
        'inc-ns1:inc-ns4:inc-ns2:test-ns3:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/app-included/test3/inner/42/37/', 'urlobject-view', 'included_namespace_urls:testapp', 'inc-app:test-ns3',
        'inc-app:test-ns3:urlobject-view', views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),
    (
        '/app-included/ns-included4/ns-included2/test3/inner/42/37/', 'urlobject-view',
        'included_namespace_urls:namespace_urls:included_namespace_urls:testapp',
        'inc-app:inc-ns4:inc-ns2:test-ns3',
        'inc-app:inc-ns4:inc-ns2:test-ns3:urlobject-view',
        views.empty_view, (), {'arg1': '42', 'arg2': '37'}
    ),

    # Namespaces capturing variables
    (
        '/inc70/', 'inner-nothing', 'included_urls', 'inc-ns5', 'inc-ns5:inner-nothing',
        views.empty_view, (), {'outer': '70'}
    ),
    (
        '/inc78/extra/foobar/', 'inner-extra', 'included_urls', 'inc-ns5', 'inc-ns5:inner-extra',
        views.empty_view, (), {'outer': '78', 'extra': 'foobar'}
    ),
)

test_data = (
    ('places', '/places/3/', [3], {}),
    ('places', '/places/3/', ['3'], {}),
    ('places', NoReverseMatch, ['a'], {}),
    ('places', NoReverseMatch, [], {}),
    ('places?', '/place/', [], {}),
    ('places+', '/places/', [], {}),
    ('places*', '/place/', [], {}),
    ('places2?', '/', [], {}),
    ('places2+', '/places/', [], {}),
    ('places2*', '/', [], {}),
    ('places3', '/places/4/', [4], {}),
    ('places3', '/places/harlem/', ['harlem'], {}),
    ('places3', NoReverseMatch, ['harlem64'], {}),
    ('places4', '/places/3/', [], {'id': 3}),
    ('people', NoReverseMatch, [], {}),
    ('people', '/people/adrian/', ['adrian'], {}),
    ('people', '/people/adrian/', [], {'name': 'adrian'}),
    ('people', NoReverseMatch, ['name with spaces'], {}),
    ('people', NoReverseMatch, [], {'name': 'name with spaces'}),
    ('people2', '/people/name/', [], {}),
    ('people2a', '/people/name/fred/', ['fred'], {}),
    ('people_backref', '/people/nate-nate/', ['nate'], {}),
    ('people_backref', '/people/nate-nate/', [], {'name': 'nate'}),
    ('optional', '/optional/fred/', [], {'name': 'fred'}),
    ('optional', '/optional/fred/', ['fred'], {}),
    ('named_optional', '/optional/1/', [1], {}),
    ('named_optional', '/optional/1/', [], {'arg1': 1}),
    ('named_optional', '/optional/1/2/', [1, 2], {}),
    ('named_optional', '/optional/1/2/', [], {'arg1': 1, 'arg2': 2}),
    ('named_optional_terminated', '/optional/1/2/', [1, 2], {}),
    ('named_optional_terminated', '/optional/1/2/', [], {'arg1': 1, 'arg2': 2}),
    ('hardcoded', '/hardcoded/', [], {}),
    ('hardcoded2', '/hardcoded/doc.pdf', [], {}),
    ('people3', '/people/il/adrian/', [], {'state': 'il', 'name': 'adrian'}),
    ('people3', NoReverseMatch, [], {'state': 'il'}),
    ('people3', NoReverseMatch, [], {'name': 'adrian'}),
    ('people4', NoReverseMatch, [], {'state': 'il', 'name': 'adrian'}),
    ('people6', '/people/il/test/adrian/', ['il/test', 'adrian'], {}),
    ('people6', '/people//adrian/', ['adrian'], {}),
    ('range', '/character_set/a/', [], {}),
    ('range2', '/character_set/x/', [], {}),
    ('price', '/price/$10/', ['10'], {}),
    ('price2', '/price/$10/', ['10'], {}),
    ('price3', '/price/$10/', ['10'], {}),
    ('product', '/product/chocolate+($2.00)/', [], {'price': '2.00', 'product': 'chocolate'}),
    ('headlines', '/headlines/2007.5.21/', [], {'year': 2007, 'month': 5, 'day': 21}),
    (
        'windows', r'/windows_path/C:%5CDocuments%20and%20Settings%5Cspam/', [],
        {'drive_name': 'C', 'path': r'Documents and Settings\spam'}
    ),
    ('special', r'/special_chars/~@+%5C$*%7C/', [r'~@+\$*|'], {}),
    ('special', r'/special_chars/some%20resource/', [r'some resource'], {}),
    ('special', r'/special_chars/10%25%20complete/', [r'10% complete'], {}),
    ('special', r'/special_chars/some%20resource/', [], {'chars': r'some resource'}),
    ('special', r'/special_chars/10%25%20complete/', [], {'chars': r'10% complete'}),
    ('special', NoReverseMatch, [''], {}),
    ('mixed', '/john/0/', [], {'name': 'john'}),
    ('repeats', '/repeats/a/', [], {}),
    ('repeats2', '/repeats/aa/', [], {}),
    ('repeats3', '/repeats/aa/', [], {}),
    ('test', '/test/1', [], {}),
    ('inner-nothing', '/outer/42/', [], {'outer': '42'}),
    ('inner-nothing', '/outer/42/', ['42'], {}),
    ('inner-nothing', NoReverseMatch, ['foo'], {}),
    ('inner-extra', '/outer/42/extra/inner/', [], {'extra': 'inner', 'outer': '42'}),
    ('inner-extra', '/outer/42/extra/inner/', ['42', 'inner'], {}),
    ('inner-extra', NoReverseMatch, ['fred', 'inner'], {}),
    ('inner-no-kwargs', '/outer-no-kwargs/42/inner-no-kwargs/1/', ['42', '1'], {}),
    ('disjunction', NoReverseMatch, ['foo'], {}),
    ('inner-disjunction', NoReverseMatch, ['10', '11'], {}),
    ('extra-places', '/e-places/10/', ['10'], {}),
    ('extra-people', '/e-people/fred/', ['fred'], {}),
    ('extra-people', '/e-people/fred/', [], {'name': 'fred'}),
    ('part', '/part/one/', [], {'value': 'one'}),
    ('part', '/prefix/xx/part/one/', [], {'value': 'one', 'prefix': 'xx'}),
    ('part2', '/part2/one/', [], {'value': 'one'}),
    ('part2', '/part2/', [], {}),
    ('part2', '/prefix/xx/part2/one/', [], {'value': 'one', 'prefix': 'xx'}),
    ('part2', '/prefix/xx/part2/', [], {'prefix': 'xx'}),

    # Tests for nested groups. Nested capturing groups will only work if you
    # *only* supply the correct outer group.
    ('nested-noncapture', '/nested/noncapture/opt', [], {'p': 'opt'}),
    ('nested-capture', '/nested/capture/opt/', ['opt/'], {}),
    ('nested-capture', NoReverseMatch, [], {'p': 'opt'}),
    ('nested-mixedcapture', '/nested/capture/mixed/opt', ['opt'], {}),
    ('nested-mixedcapture', NoReverseMatch, [], {'p': 'opt'}),
    ('nested-namedcapture', '/nested/capture/named/opt/', [], {'outer': 'opt/'}),
    ('nested-namedcapture', NoReverseMatch, [], {'outer': 'opt/', 'inner': 'opt'}),
    ('nested-namedcapture', NoReverseMatch, [], {'inner': 'opt'}),

    ('non_path_include', '/includes/non_path_include/', [], {}),

    # Tests for #13154
    ('defaults', '/defaults_view1/3/', [], {'arg1': 3, 'arg2': 1}),
    ('defaults', '/defaults_view2/3/', [], {'arg1': 3, 'arg2': 2}),
    ('defaults', NoReverseMatch, [], {'arg1': 3, 'arg2': 3}),
    ('defaults', NoReverseMatch, [], {'arg2': 1}),

    # Security tests
    ('security', '/%2Fexample.com/security/', ['/example.com'], {}),
)


@override_settings(ROOT_URLCONF='urlpatterns_reverse.no_urls')
class NoURLPatternsTests(SimpleTestCase):

    def test_no_urls_exception(self):
        """
        URLResolver should raise an exception when no urlpatterns exist.
        """
        resolver = URLResolver(RegexPattern(r'^$'), settings.ROOT_URLCONF)

        with self.assertRaisesMessage(
            ImproperlyConfigured,
            "The included URLconf 'urlpatterns_reverse.no_urls' does not "
            "appear to have any patterns in it. If you see valid patterns in "
            "the file then the issue is probably caused by a circular import."
        ):
            getattr(resolver, 'url_patterns')


@override_settings(ROOT_URLCONF='urlpatterns_reverse.urls')
class URLPatternReverse(SimpleTestCase):

    def test_urlpattern_reverse(self):
        for name, expected, args, kwargs in test_data:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                try:
                    got = reverse(name, args=args, kwargs=kwargs)
                except NoReverseMatch:
                    self.assertEqual(NoReverseMatch, expected)
                else:
                    self.assertEqual(got, expected)

    def test_reverse_none(self):
        # Reversing None should raise an error, not return the last un-named view.
        with self.assertRaises(NoReverseMatch):
            reverse(None)

    def test_mixing_args_and_kwargs(self):
        msg = "Don't mix *args and **kwargs in call to reverse()!"
        with self.assertRaisesMessage(ValueError, msg):
            reverse('name', args=['a'], kwargs={'b': 'c'})

    @override_script_prefix('/{{invalid}}/')
    def test_prefix_braces(self):
        self.assertEqual(
            '/%7B%7Binvalid%7D%7D/includes/non_path_include/',
            reverse('non_path_include')
        )

    def test_prefix_parenthesis(self):
        # Parentheses are allowed and should not cause errors or be escaped
        with override_script_prefix('/bogus)/'):
            self.assertEqual(
                '/bogus)/includes/non_path_include/',
                reverse('non_path_include')
            )
        with override_script_prefix('/(bogus)/'):
            self.assertEqual(
                '/(bogus)/includes/non_path_include/',
                reverse('non_path_include')
            )

    @override_script_prefix('/bump%20map/')
    def test_prefix_format_char(self):
        self.assertEqual(
            '/bump%2520map/includes/non_path_include/',
            reverse('non_path_include')
        )

    @override_script_prefix('/%7Eme/')
    def test_non_urlsafe_prefix_with_args(self):
        # Regression for #20022, adjusted for #24013 because ~ is an unreserved
        # character. Tests whether % is escaped.
        self.assertEqual('/%257Eme/places/1/', reverse('places', args=[1]))

    def test_patterns_reported(self):
        # Regression for #17076
        with self.assertRaisesMessage(NoReverseMatch, r"1 pattern(s) tried: ['people/(?P<name>\\w+)/$']"):
            # this url exists, but requires an argument
            reverse("people", args=[])

    @override_script_prefix('/script:name/')
    def test_script_name_escaping(self):
        self.assertEqual(
            reverse('optional', args=['foo:bar']),
            '/script:name/optional/foo:bar/'
        )

    def test_view_not_found_message(self):
        msg = (
            "Reverse for 'nonexistent-view' not found. 'nonexistent-view' "
            "is not a valid view function or pattern name."
        )
        with self.assertRaisesMessage(NoReverseMatch, msg):
            reverse('nonexistent-view')

    def test_no_args_message(self):
        msg = "Reverse for 'places' with no arguments not found. 1 pattern(s) tried:"
        with self.assertRaisesMessage(NoReverseMatch, msg):
            reverse('places')

    def test_illegal_args_message(self):
        msg = "Reverse for 'places' with arguments '(1, 2)' not found. 1 pattern(s) tried:"
        with self.assertRaisesMessage(NoReverseMatch, msg):
            reverse('places', args=(1, 2))

    def test_illegal_kwargs_message(self):
        msg = "Reverse for 'places' with keyword arguments '{'arg1': 2}' not found. 1 pattern(s) tried:"
        with self.assertRaisesMessage(NoReverseMatch, msg):
            reverse('places', kwargs={'arg1': 2})


class ResolverTests(SimpleTestCase):
    def test_resolver_repr(self):
        """
        Test repr of URLResolver, especially when urlconf_name is a list
        (#17892).
        """
        # Pick a resolver from a namespaced URLconf
        resolver = get_resolver('urlpatterns_reverse.namespace_urls')
        sub_resolver = resolver.namespace_dict['test-ns1'][1]
        self.assertIn('<URLPattern list>', repr(sub_resolver))

    def test_reverse_lazy_object_coercion_by_resolve(self):
        """
        Verifies lazy object returned by reverse_lazy is coerced to
        text by resolve(). Previous to #21043, this would raise a TypeError.
        """
        urls = 'urlpatterns_reverse.named_urls'
        proxy_url = reverse_lazy('named-url1', urlconf=urls)
        resolver = get_resolver(urls)
        resolver.resolve(proxy_url)

    def test_resolver_reverse(self):
        resolver = get_resolver('urlpatterns_reverse.named_urls')
        test_urls = [
            # (name, args, kwargs, expected)
            ('named-url1', (), {}, ''),
            ('named-url2', ('arg',), {}, 'extra/arg/'),
            ('named-url2', (), {'extra': 'arg'}, 'extra/arg/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(resolver.reverse(name, *args, **kwargs), expected)

    def test_resolver_reverse_conflict(self):
        """
        url() name arguments don't need to be unique. The last registered
        pattern takes precedence for conflicting names.
        """
        resolver = get_resolver('urlpatterns_reverse.named_urls_conflict')
        test_urls = [
            # (name, args, kwargs, expected)
            # Without arguments, the last URL in urlpatterns has precedence.
            ('name-conflict', (), {}, 'conflict/'),
            # With an arg, the last URL in urlpatterns has precedence.
            ('name-conflict', ('arg',), {}, 'conflict-last/arg/'),
            # With a kwarg, other url()s can be reversed.
            ('name-conflict', (), {'first': 'arg'}, 'conflict-first/arg/'),
            ('name-conflict', (), {'middle': 'arg'}, 'conflict-middle/arg/'),
            ('name-conflict', (), {'last': 'arg'}, 'conflict-last/arg/'),
            # The number and order of the arguments don't interfere with reversing.
            ('name-conflict', ('arg', 'arg'), {}, 'conflict/arg/arg/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(resolver.reverse(name, *args, **kwargs), expected)

    def test_non_regex(self):
        """
        A Resolver404 is raised if resolving doesn't meet the basic
        requirements of a path to match - i.e., at the very least, it matches
        the root pattern '^/'. Never return None from resolve() to prevent a
        TypeError from occurring later (#10834).
        """
        test_urls = ['', 'a', '\\', '.']
        for path in test_urls:
            with self.subTest(path=path):
                with self.assertRaises(Resolver404):
                    resolve(path)

    def test_404_tried_urls_have_names(self):
        """
        The list of URLs that come back from a Resolver404 exception contains
        a list in the right format for printing out in the DEBUG 404 page with
        both the patterns and URL names, if available.
        """
        urls = 'urlpatterns_reverse.named_urls'
        # this list matches the expected URL types and names returned when
        # you try to resolve a nonexistent URL in the first level of included
        # URLs in named_urls.py (e.g., '/included/nonexistent-url')
        url_types_names = [
            [{'type': URLPattern, 'name': 'named-url1'}],
            [{'type': URLPattern, 'name': 'named-url2'}],
            [{'type': URLPattern, 'name': None}],
            [{'type': URLResolver}, {'type': URLPattern, 'name': 'named-url3'}],
            [{'type': URLResolver}, {'type': URLPattern, 'name': 'named-url4'}],
            [{'type': URLResolver}, {'type': URLPattern, 'name': None}],
            [{'type': URLResolver}, {'type': URLResolver}],
        ]
        with self.assertRaisesMessage(Resolver404, 'tried') as cm:
            resolve('/included/nonexistent-url', urlconf=urls)
        e = cm.exception
        # make sure we at least matched the root ('/') url resolver:
        self.assertIn('tried', e.args[0])
        self.assertEqual(
            len(e.args[0]['tried']),
            len(url_types_names),
            'Wrong number of tried URLs returned.  Expected %s, got %s.' % (
                len(url_types_names), len(e.args[0]['tried'])
            )
        )
        for tried, expected in zip(e.args[0]['tried'], url_types_names):
            for t, e in zip(tried, expected):
                with self.subTest(t):
                    self.assertIsInstance(t, e['type']), '%s is not an instance of %s' % (t, e['type'])
                    if 'name' in e:
                        if not e['name']:
                            self.assertIsNone(t.name, 'Expected no URL name but found %s.' % t.name)
                        else:
                            self.assertEqual(
                                t.name,
                                e['name'],
                                'Wrong URL name.  Expected "%s", got "%s".' % (e['name'], t.name)
                            )

    def test_namespaced_view_detail(self):
        resolver = get_resolver('urlpatterns_reverse.nested_urls')
        self.assertTrue(resolver._is_callback('urlpatterns_reverse.nested_urls.view1'))
        self.assertTrue(resolver._is_callback('urlpatterns_reverse.nested_urls.view2'))
        self.assertTrue(resolver._is_callback('urlpatterns_reverse.nested_urls.View3'))
        self.assertFalse(resolver._is_callback('urlpatterns_reverse.nested_urls.blub'))

    def test_view_detail_as_method(self):
        # Views which have a class name as part of their path.
        resolver = get_resolver('urlpatterns_reverse.method_view_urls')
        self.assertTrue(resolver._is_callback('urlpatterns_reverse.method_view_urls.ViewContainer.method_view'))
        self.assertTrue(resolver._is_callback('urlpatterns_reverse.method_view_urls.ViewContainer.classmethod_view'))

    def test_populate_concurrency(self):
        """
        URLResolver._populate() can be called concurrently, but not more
        than once per thread (#26888).
        """
        resolver = URLResolver(RegexPattern(r'^/'), 'urlpatterns_reverse.urls')
        resolver._local.populating = True
        thread = threading.Thread(target=resolver._populate)
        thread.start()
        thread.join()
        self.assertNotEqual(resolver._reverse_dict, {})


@override_settings(ROOT_URLCONF='urlpatterns_reverse.reverse_lazy_urls')
class ReverseLazyTest(TestCase):

    def test_redirect_with_lazy_reverse(self):
        response = self.client.get('/redirect/')
        self.assertRedirects(response, "/redirected_to/", status_code=302)

    def test_user_permission_with_lazy_reverse(self):
        alfred = User.objects.create_user('alfred', 'alfred@example.com', password='testpw')
        response = self.client.get('/login_required_view/')
        self.assertRedirects(response, "/login/?next=/login_required_view/", status_code=302)
        self.client.force_login(alfred)
        response = self.client.get('/login_required_view/')
        self.assertEqual(response.status_code, 200)

    def test_inserting_reverse_lazy_into_string(self):
        self.assertEqual(
            'Some URL: %s' % reverse_lazy('some-login-page'),
            'Some URL: /login/'
        )


class ReverseLazySettingsTest(AdminScriptTestCase):
    """
    reverse_lazy can be used in settings without causing a circular
    import error.
    """
    def setUp(self):
        self.write_settings('settings.py', extra="""
from django.urls import reverse_lazy
LOGIN_URL = reverse_lazy('login')""")

    def tearDown(self):
        self.remove_settings('settings.py')

    def test_lazy_in_settings(self):
        out, err = self.run_manage(['check'])
        self.assertNoOutput(err)


@override_settings(ROOT_URLCONF='urlpatterns_reverse.urls')
class ReverseShortcutTests(SimpleTestCase):

    def test_redirect_to_object(self):
        # We don't really need a model; just something with a get_absolute_url
        class FakeObj:
            def get_absolute_url(self):
                return "/hi-there/"

        res = redirect(FakeObj())
        self.assertIsInstance(res, HttpResponseRedirect)
        self.assertEqual(res.url, '/hi-there/')

        res = redirect(FakeObj(), permanent=True)
        self.assertIsInstance(res, HttpResponsePermanentRedirect)
        self.assertEqual(res.url, '/hi-there/')

    def test_redirect_to_view_name(self):
        res = redirect('hardcoded2')
        self.assertEqual(res.url, '/hardcoded/doc.pdf')
        res = redirect('places', 1)
        self.assertEqual(res.url, '/places/1/')
        res = redirect('headlines', year='2008', month='02', day='17')
        self.assertEqual(res.url, '/headlines/2008.02.17/')
        with self.assertRaises(NoReverseMatch):
            redirect('not-a-view')

    def test_redirect_to_url(self):
        res = redirect('/foo/')
        self.assertEqual(res.url, '/foo/')
        res = redirect('http://example.com/')
        self.assertEqual(res.url, 'http://example.com/')
        # Assert that we can redirect using UTF-8 strings
        res = redirect('/æøå/abc/')
        self.assertEqual(res.url, '/%C3%A6%C3%B8%C3%A5/abc/')
        # Assert that no imports are attempted when dealing with a relative path
        # (previously, the below would resolve in a UnicodeEncodeError from __import__ )
        res = redirect('/æøå.abc/')
        self.assertEqual(res.url, '/%C3%A6%C3%B8%C3%A5.abc/')
        res = redirect('os.path')
        self.assertEqual(res.url, 'os.path')

    def test_no_illegal_imports(self):
        # modules that are not listed in urlpatterns should not be importable
        redirect("urlpatterns_reverse.nonimported_module.view")
        self.assertNotIn("urlpatterns_reverse.nonimported_module", sys.modules)

    def test_reverse_by_path_nested(self):
        # Views added to urlpatterns using include() should be reversible.
        from .views import nested_view
        self.assertEqual(reverse(nested_view), '/includes/nested_path/')

    def test_redirect_view_object(self):
        from .views import absolute_kwargs_view
        res = redirect(absolute_kwargs_view)
        self.assertEqual(res.url, '/absolute_arg_view/')
        with self.assertRaises(NoReverseMatch):
            redirect(absolute_kwargs_view, wrong_argument=None)


@override_settings(ROOT_URLCONF='urlpatterns_reverse.namespace_urls')
class NamespaceTests(SimpleTestCase):

    def test_ambiguous_object(self):
        """
        Names deployed via dynamic URL objects that require namespaces can't
        be resolved.
        """
        test_urls = [
            ('urlobject-view', [], {}),
            ('urlobject-view', [37, 42], {}),
            ('urlobject-view', [], {'arg1': 42, 'arg2': 37}),
        ]
        for name, args, kwargs in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                with self.assertRaises(NoReverseMatch):
                    reverse(name, args=args, kwargs=kwargs)

    def test_ambiguous_urlpattern(self):
        """
        Names deployed via dynamic URL objects that require namespaces can't
        be resolved.
        """
        test_urls = [
            ('inner-nothing', [], {}),
            ('inner-nothing', [37, 42], {}),
            ('inner-nothing', [], {'arg1': 42, 'arg2': 37}),
        ]
        for name, args, kwargs in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                with self.assertRaises(NoReverseMatch):
                    reverse(name, args=args, kwargs=kwargs)

    def test_non_existent_namespace(self):
        """Nonexistent namespaces raise errors."""
        test_urls = [
            'blahblah:urlobject-view',
            'test-ns1:blahblah:urlobject-view',
        ]
        for name in test_urls:
            with self.subTest(name=name):
                with self.assertRaises(NoReverseMatch):
                    reverse(name)

    def test_normal_name(self):
        """Normal lookups work as expected."""
        test_urls = [
            ('normal-view', [], {}, '/normal/'),
            ('normal-view', [37, 42], {}, '/normal/37/42/'),
            ('normal-view', [], {'arg1': 42, 'arg2': 37}, '/normal/42/37/'),
            ('special-view', [], {}, '/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_simple_included_name(self):
        """Normal lookups work on names included from other patterns."""
        test_urls = [
            ('included_namespace_urls:inc-normal-view', [], {}, '/included/normal/'),
            ('included_namespace_urls:inc-normal-view', [37, 42], {}, '/included/normal/37/42/'),
            ('included_namespace_urls:inc-normal-view', [], {'arg1': 42, 'arg2': 37}, '/included/normal/42/37/'),
            ('included_namespace_urls:inc-special-view', [], {}, '/included/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_namespace_object(self):
        """Dynamic URL objects can be found using a namespace."""
        test_urls = [
            ('test-ns1:urlobject-view', [], {}, '/test1/inner/'),
            ('test-ns1:urlobject-view', [37, 42], {}, '/test1/inner/37/42/'),
            ('test-ns1:urlobject-view', [], {'arg1': 42, 'arg2': 37}, '/test1/inner/42/37/'),
            ('test-ns1:urlobject-special-view', [], {}, '/test1/inner/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_app_object(self):
        """
        Dynamic URL objects can return a (pattern, app_name) 2-tuple, and
        include() can set the namespace.
        """
        test_urls = [
            ('new-ns1:urlobject-view', [], {}, '/newapp1/inner/'),
            ('new-ns1:urlobject-view', [37, 42], {}, '/newapp1/inner/37/42/'),
            ('new-ns1:urlobject-view', [], {'arg1': 42, 'arg2': 37}, '/newapp1/inner/42/37/'),
            ('new-ns1:urlobject-special-view', [], {}, '/newapp1/inner/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_app_object_default_namespace(self):
        """
        Namespace defaults to app_name when including a (pattern, app_name)
        2-tuple.
        """
        test_urls = [
            ('newapp:urlobject-view', [], {}, '/new-default/inner/'),
            ('newapp:urlobject-view', [37, 42], {}, '/new-default/inner/37/42/'),
            ('newapp:urlobject-view', [], {'arg1': 42, 'arg2': 37}, '/new-default/inner/42/37/'),
            ('newapp:urlobject-special-view', [], {}, '/new-default/inner/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_embedded_namespace_object(self):
        """Namespaces can be installed anywhere in the URL pattern tree."""
        test_urls = [
            ('included_namespace_urls:test-ns3:urlobject-view', [], {}, '/included/test3/inner/'),
            ('included_namespace_urls:test-ns3:urlobject-view', [37, 42], {}, '/included/test3/inner/37/42/'),
            (
                'included_namespace_urls:test-ns3:urlobject-view', [], {'arg1': 42, 'arg2': 37},
                '/included/test3/inner/42/37/',
            ),
            ('included_namespace_urls:test-ns3:urlobject-special-view', [], {}, '/included/test3/inner/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_namespace_pattern(self):
        """Namespaces can be applied to include()'d urlpatterns."""
        test_urls = [
            ('inc-ns1:inc-normal-view', [], {}, '/ns-included1/normal/'),
            ('inc-ns1:inc-normal-view', [37, 42], {}, '/ns-included1/normal/37/42/'),
            ('inc-ns1:inc-normal-view', [], {'arg1': 42, 'arg2': 37}, '/ns-included1/normal/42/37/'),
            ('inc-ns1:inc-special-view', [], {}, '/ns-included1/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_app_name_pattern(self):
        """
        Namespaces can be applied to include()'d urlpatterns that set an
        app_name attribute.
        """
        test_urls = [
            ('app-ns1:inc-normal-view', [], {}, '/app-included1/normal/'),
            ('app-ns1:inc-normal-view', [37, 42], {}, '/app-included1/normal/37/42/'),
            ('app-ns1:inc-normal-view', [], {'arg1': 42, 'arg2': 37}, '/app-included1/normal/42/37/'),
            ('app-ns1:inc-special-view', [], {}, '/app-included1/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_namespace_pattern_with_variable_prefix(self):
        """
        Using include() with namespaces when there is a regex variable in front
        of it.
        """
        test_urls = [
            ('inc-outer:inc-normal-view', [], {'outer': 42}, '/ns-outer/42/normal/'),
            ('inc-outer:inc-normal-view', [42], {}, '/ns-outer/42/normal/'),
            ('inc-outer:inc-normal-view', [], {'arg1': 37, 'arg2': 4, 'outer': 42}, '/ns-outer/42/normal/37/4/'),
            ('inc-outer:inc-normal-view', [42, 37, 4], {}, '/ns-outer/42/normal/37/4/'),
            ('inc-outer:inc-special-view', [], {'outer': 42}, '/ns-outer/42/+%5C$*/'),
            ('inc-outer:inc-special-view', [42], {}, '/ns-outer/42/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_multiple_namespace_pattern(self):
        """Namespaces can be embedded."""
        test_urls = [
            ('inc-ns1:test-ns3:urlobject-view', [], {}, '/ns-included1/test3/inner/'),
            ('inc-ns1:test-ns3:urlobject-view', [37, 42], {}, '/ns-included1/test3/inner/37/42/'),
            (
                'inc-ns1:test-ns3:urlobject-view', [], {'arg1': 42, 'arg2': 37},
                '/ns-included1/test3/inner/42/37/',
            ),
            ('inc-ns1:test-ns3:urlobject-special-view', [], {}, '/ns-included1/test3/inner/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_nested_namespace_pattern(self):
        """Namespaces can be nested."""
        test_urls = [
            (
                'inc-ns1:inc-ns4:inc-ns1:test-ns3:urlobject-view', [], {},
                '/ns-included1/ns-included4/ns-included1/test3/inner/',
            ),
            (
                'inc-ns1:inc-ns4:inc-ns1:test-ns3:urlobject-view', [37, 42], {},
                '/ns-included1/ns-included4/ns-included1/test3/inner/37/42/',
            ),
            (
                'inc-ns1:inc-ns4:inc-ns1:test-ns3:urlobject-view', [], {'arg1': 42, 'arg2': 37},
                '/ns-included1/ns-included4/ns-included1/test3/inner/42/37/',
            ),
            (
                'inc-ns1:inc-ns4:inc-ns1:test-ns3:urlobject-special-view', [], {},
                '/ns-included1/ns-included4/ns-included1/test3/inner/+%5C$*/',
            ),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_app_lookup_object(self):
        """A default application namespace can be used for lookup."""
        test_urls = [
            ('testapp:urlobject-view', [], {}, '/default/inner/'),
            ('testapp:urlobject-view', [37, 42], {}, '/default/inner/37/42/'),
            ('testapp:urlobject-view', [], {'arg1': 42, 'arg2': 37}, '/default/inner/42/37/'),
            ('testapp:urlobject-special-view', [], {}, '/default/inner/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_app_lookup_object_with_default(self):
        """A default application namespace is sensitive to the current app."""
        test_urls = [
            ('testapp:urlobject-view', [], {}, 'test-ns3', '/default/inner/'),
            ('testapp:urlobject-view', [37, 42], {}, 'test-ns3', '/default/inner/37/42/'),
            ('testapp:urlobject-view', [], {'arg1': 42, 'arg2': 37}, 'test-ns3', '/default/inner/42/37/'),
            ('testapp:urlobject-special-view', [], {}, 'test-ns3', '/default/inner/+%5C$*/'),
        ]
        for name, args, kwargs, current_app, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs, current_app=current_app):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs, current_app=current_app), expected)

    def test_app_lookup_object_without_default(self):
        """
        An application namespace without a default is sensitive to the current
        app.
        """
        test_urls = [
            ('nodefault:urlobject-view', [], {}, None, '/other2/inner/'),
            ('nodefault:urlobject-view', [37, 42], {}, None, '/other2/inner/37/42/'),
            ('nodefault:urlobject-view', [], {'arg1': 42, 'arg2': 37}, None, '/other2/inner/42/37/'),
            ('nodefault:urlobject-special-view', [], {}, None, '/other2/inner/+%5C$*/'),
            ('nodefault:urlobject-view', [], {}, 'other-ns1', '/other1/inner/'),
            ('nodefault:urlobject-view', [37, 42], {}, 'other-ns1', '/other1/inner/37/42/'),
            ('nodefault:urlobject-view', [], {'arg1': 42, 'arg2': 37}, 'other-ns1', '/other1/inner/42/37/'),
            ('nodefault:urlobject-special-view', [], {}, 'other-ns1', '/other1/inner/+%5C$*/'),
        ]
        for name, args, kwargs, current_app, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs, current_app=current_app):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs, current_app=current_app), expected)

    def test_special_chars_namespace(self):
        test_urls = [
            ('special:included_namespace_urls:inc-normal-view', [], {}, '/+%5C$*/included/normal/'),
            ('special:included_namespace_urls:inc-normal-view', [37, 42], {}, '/+%5C$*/included/normal/37/42/'),
            (
                'special:included_namespace_urls:inc-normal-view', [], {'arg1': 42, 'arg2': 37},
                '/+%5C$*/included/normal/42/37/',
            ),
            ('special:included_namespace_urls:inc-special-view', [], {}, '/+%5C$*/included/+%5C$*/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_namespaces_with_variables(self):
        """Namespace prefixes can capture variables."""
        test_urls = [
            ('inc-ns5:inner-nothing', [], {'outer': '70'}, '/inc70/'),
            ('inc-ns5:inner-extra', [], {'extra': 'foobar', 'outer': '78'}, '/inc78/extra/foobar/'),
            ('inc-ns5:inner-nothing', ['70'], {}, '/inc70/'),
            ('inc-ns5:inner-extra', ['78', 'foobar'], {}, '/inc78/extra/foobar/'),
        ]
        for name, args, kwargs, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs), expected)

    def test_nested_app_lookup(self):
        """
        A nested current_app should be split in individual namespaces (#24904).
        """
        test_urls = [
            ('inc-ns1:testapp:urlobject-view', [], {}, None, '/ns-included1/test4/inner/'),
            ('inc-ns1:testapp:urlobject-view', [37, 42], {}, None, '/ns-included1/test4/inner/37/42/'),
            ('inc-ns1:testapp:urlobject-view', [], {'arg1': 42, 'arg2': 37}, None, '/ns-included1/test4/inner/42/37/'),
            ('inc-ns1:testapp:urlobject-special-view', [], {}, None, '/ns-included1/test4/inner/+%5C$*/'),
            ('inc-ns1:testapp:urlobject-view', [], {}, 'inc-ns1:test-ns3', '/ns-included1/test3/inner/'),
            ('inc-ns1:testapp:urlobject-view', [37, 42], {}, 'inc-ns1:test-ns3', '/ns-included1/test3/inner/37/42/'),
            (
                'inc-ns1:testapp:urlobject-view', [], {'arg1': 42, 'arg2': 37}, 'inc-ns1:test-ns3',
                '/ns-included1/test3/inner/42/37/',
            ),
            (
                'inc-ns1:testapp:urlobject-special-view', [], {}, 'inc-ns1:test-ns3',
                '/ns-included1/test3/inner/+%5C$*/',
            ),
        ]
        for name, args, kwargs, current_app, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs, current_app=current_app):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs, current_app=current_app), expected)

    def test_current_app_no_partial_match(self):
        """current_app shouldn't be used unless it matches the whole path."""
        test_urls = [
            ('inc-ns1:testapp:urlobject-view', [], {}, 'nonexistent:test-ns3', '/ns-included1/test4/inner/'),
            (
                'inc-ns1:testapp:urlobject-view', [37, 42], {}, 'nonexistent:test-ns3',
                '/ns-included1/test4/inner/37/42/',
            ),
            (
                'inc-ns1:testapp:urlobject-view', [], {'arg1': 42, 'arg2': 37}, 'nonexistent:test-ns3',
                '/ns-included1/test4/inner/42/37/',
            ),
            (
                'inc-ns1:testapp:urlobject-special-view', [], {}, 'nonexistent:test-ns3',
                '/ns-included1/test4/inner/+%5C$*/',
            ),
        ]
        for name, args, kwargs, current_app, expected in test_urls:
            with self.subTest(name=name, args=args, kwargs=kwargs, current_app=current_app):
                self.assertEqual(reverse(name, args=args, kwargs=kwargs, current_app=current_app), expected)


@override_settings(ROOT_URLCONF=urlconf_outer.__name__)
class RequestURLconfTests(SimpleTestCase):
    def test_urlconf(self):
        response = self.client.get('/test/me/')
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.content, b'outer:/test/me/,inner:/inner_urlconf/second_test/')
        response = self.client.get('/inner_urlconf/second_test/')
        self.assertEqual(response.status_code, 200)
        response = self.client.get('/second_test/')
        self.assertEqual(response.status_code, 404)

    @override_settings(
        MIDDLEWARE=[
            '%s.ChangeURLconfMiddleware' % middleware.__name__,
        ]
    )
    def test_urlconf_overridden(self):
        response = self.client.get('/test/me/')
        self.assertEqual(response.status_code, 404)
        response = self.client.get('/inner_urlconf/second_test/')
        self.assertEqual(response.status_code, 404)
        response = self.client.get('/second_test/')
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.content, b'outer:,inner:/second_test/')

    @override_settings(
        MIDDLEWARE=[
            '%s.NullChangeURLconfMiddleware' % middleware.__name__,
        ]
    )
    def test_urlconf_overridden_with_null(self):
        """
        Overriding request.urlconf with None will fall back to the default
        URLconf.
        """
        response = self.client.get('/test/me/')
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.content, b'outer:/test/me/,inner:/inner_urlconf/second_test/')
        response = self.client.get('/inner_urlconf/second_test/')
        self.assertEqual(response.status_code, 200)
        response = self.client.get('/second_test/')
        self.assertEqual(response.status_code, 404)

    @override_settings(
        MIDDLEWARE=[
            '%s.ChangeURLconfMiddleware' % middleware.__name__,
            '%s.ReverseInnerInResponseMiddleware' % middleware.__name__,
        ]
    )
    def test_reverse_inner_in_response_middleware(self):
        """
        Test reversing an URL from the *overridden* URLconf from inside
        a response middleware.
        """
        response = self.client.get('/second_test/')
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.content, b'/second_test/')

    @override_settings(
        MIDDLEWARE=[
            '%s.ChangeURLconfMiddleware' % middleware.__name__,
            '%s.ReverseOuterInResponseMiddleware' % middleware.__name__,
        ]
    )
    def test_reverse_outer_in_response_middleware(self):
        """
        Test reversing an URL from the *default* URLconf from inside
        a response middleware.
        """
        message = "Reverse for 'outer' not found."
        with self.assertRaisesMessage(NoReverseMatch, message):
            self.client.get('/second_test/')

    @override_settings(
        MIDDLEWARE=[
            '%s.ChangeURLconfMiddleware' % middleware.__name__,
            '%s.ReverseInnerInStreaming' % middleware.__name__,
        ]
    )
    def test_reverse_inner_in_streaming(self):
        """
        Test reversing an URL from the *overridden* URLconf from inside
        a streaming response.
        """
        response = self.client.get('/second_test/')
        self.assertEqual(response.status_code, 200)
        self.assertEqual(b''.join(response), b'/second_test/')

    @override_settings(
        MIDDLEWARE=[
            '%s.ChangeURLconfMiddleware' % middleware.__name__,
            '%s.ReverseOuterInStreaming' % middleware.__name__,
        ]
    )
    def test_reverse_outer_in_streaming(self):
        """
        Test reversing an URL from the *default* URLconf from inside
        a streaming response.
        """
        message = "Reverse for 'outer' not found."
        with self.assertRaisesMessage(NoReverseMatch, message):
            self.client.get('/second_test/')
            b''.join(self.client.get('/second_test/'))


class ErrorHandlerResolutionTests(SimpleTestCase):
    """Tests for handler400, handler404 and handler500"""

    def setUp(self):
        urlconf = 'urlpatterns_reverse.urls_error_handlers'
        urlconf_callables = 'urlpatterns_reverse.urls_error_handlers_callables'
        self.resolver = URLResolver(RegexPattern(r'^$'), urlconf)
        self.callable_resolver = URLResolver(RegexPattern(r'^$'), urlconf_callables)

    def test_named_handlers(self):
        handler = (empty_view, {})
        for code in [400, 404, 500]:
            with self.subTest(code=code):
                self.assertEqual(self.resolver.resolve_error_handler(code), handler)

    def test_callable_handlers(self):
        handler = (empty_view, {})
        for code in [400, 404, 500]:
            with self.subTest(code=code):
                self.assertEqual(self.callable_resolver.resolve_error_handler(code), handler)


@override_settings(ROOT_URLCONF='urlpatterns_reverse.urls_without_full_import')
class DefaultErrorHandlerTests(SimpleTestCase):

    def test_default_handler(self):
        "If the urls.py doesn't specify handlers, the defaults are used"
        response = self.client.get('/test/')
        self.assertEqual(response.status_code, 404)

        with self.assertRaisesMessage(ValueError, "I don't think I'm getting good"):
            self.client.get('/bad_view/')


@override_settings(ROOT_URLCONF=None)
class NoRootUrlConfTests(SimpleTestCase):
    """Tests for handler404 and handler500 if ROOT_URLCONF is None"""

    def test_no_handler_exception(self):
        msg = (
            "The included URLconf 'None' does not appear to have any patterns "
            "in it. If you see valid patterns in the file then the issue is "
            "probably caused by a circular import."
        )
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            self.client.get('/test/me/')


@override_settings(ROOT_URLCONF='urlpatterns_reverse.namespace_urls')
class ResolverMatchTests(SimpleTestCase):

    def test_urlpattern_resolve(self):
        for path, url_name, app_name, namespace, view_name, func, args, kwargs in resolve_test_data:
            with self.subTest(path=path):
                # Legacy support for extracting "function, args, kwargs".
                match_func, match_args, match_kwargs = resolve(path)
                self.assertEqual(match_func, func)
                self.assertEqual(match_args, args)
                self.assertEqual(match_kwargs, kwargs)
                # ResolverMatch capabilities.
                match = resolve(path)
                self.assertEqual(match.__class__, ResolverMatch)
                self.assertEqual(match.url_name, url_name)
                self.assertEqual(match.app_name, app_name)
                self.assertEqual(match.namespace, namespace)
                self.assertEqual(match.view_name, view_name)
                self.assertEqual(match.func, func)
                self.assertEqual(match.args, args)
                self.assertEqual(match.kwargs, kwargs)
                # and for legacy purposes:
                self.assertEqual(match[0], func)
                self.assertEqual(match[1], args)
                self.assertEqual(match[2], kwargs)

    def test_resolver_match_on_request(self):
        response = self.client.get('/resolver_match/')
        resolver_match = response.resolver_match
        self.assertEqual(resolver_match.url_name, 'test-resolver-match')

    def test_resolver_match_on_request_before_resolution(self):
        request = HttpRequest()
        self.assertIsNone(request.resolver_match)


@override_settings(ROOT_URLCONF='urlpatterns_reverse.erroneous_urls')
class ErroneousViewTests(SimpleTestCase):

    def test_noncallable_view(self):
        # View is not a callable (explicit import; arbitrary Python object)
        with self.assertRaisesMessage(TypeError, 'view must be a callable'):
            url(r'uncallable-object/$', views.uncallable)

    def test_invalid_regex(self):
        # Regex contains an error (refs #6170)
        msg = '(regex_error/$" is not a valid regular expression'
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            reverse(views.empty_view)


class ViewLoadingTests(SimpleTestCase):
    def test_view_loading(self):
        self.assertEqual(get_callable('urlpatterns_reverse.views.empty_view'), empty_view)

        # passing a callable should return the callable
        self.assertEqual(get_callable(empty_view), empty_view)

    def test_exceptions(self):
        # A missing view (identified by an AttributeError) should raise
        # ViewDoesNotExist, ...
        with self.assertRaisesMessage(ViewDoesNotExist, "View does not exist in"):
            get_callable('urlpatterns_reverse.views.i_should_not_exist')
        # ... but if the AttributeError is caused by something else don't
        # swallow it.
        with self.assertRaises(AttributeError):
            get_callable('urlpatterns_reverse.views_broken.i_am_broken')


class IncludeTests(SimpleTestCase):
    url_patterns = [
        url(r'^inner/$', views.empty_view, name='urlobject-view'),
        url(r'^inner/(?P<arg1>[0-9]+)/(?P<arg2>[0-9]+)/$', views.empty_view, name='urlobject-view'),
        url(r'^inner/\+\\\$\*/$', views.empty_view, name='urlobject-special-view'),
    ]
    app_urls = URLObject('inc-app')

    def test_include_urls(self):
        self.assertEqual(include(self.url_patterns), (self.url_patterns, None, None))

    def test_include_namespace(self):
        msg = (
            'Specifying a namespace in include() without providing an '
            'app_name is not supported.'
        )
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            include(self.url_patterns, 'namespace')

    def test_include_4_tuple(self):
        msg = 'Passing a 4-tuple to include() is not supported.'
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            include((self.url_patterns, 'app_name', 'namespace', 'blah'))

    def test_include_3_tuple(self):
        msg = 'Passing a 3-tuple to include() is not supported.'
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            include((self.url_patterns, 'app_name', 'namespace'))

    def test_include_3_tuple_namespace(self):
        msg = 'Cannot override the namespace for a dynamic module that provides a namespace.'
        with self.assertRaisesMessage(ImproperlyConfigured, msg):
            include((self.url_patterns, 'app_name', 'namespace'), 'namespace')

    def test_include_2_tuple(self):
        self.assertEqual(
            include((self.url_patterns, 'app_name')),
            (self.url_patterns, 'app_name', 'app_name')
        )

    def test_include_2_tuple_namespace(self):
        self.assertEqual(
            include((self.url_patterns, 'app_name'), namespace='namespace'),
            (self.url_patterns, 'app_name', 'namespace')
        )

    def test_include_app_name(self):
        self.assertEqual(
            include(self.app_urls),
            (self.app_urls, 'inc-app', 'inc-app')
        )

    def test_include_app_name_namespace(self):
        self.assertEqual(
            include(self.app_urls, 'namespace'),
            (self.app_urls, 'inc-app', 'namespace')
        )


@override_settings(ROOT_URLCONF='urlpatterns_reverse.urls')
class LookaheadTests(SimpleTestCase):
    def test_valid_resolve(self):
        test_urls = [
            '/lookahead-/a-city/',
            '/lookbehind-/a-city/',
            '/lookahead+/a-city/',
            '/lookbehind+/a-city/',
        ]
        for test_url in test_urls:
            with self.subTest(url=test_url):
                self.assertEqual(resolve(test_url).kwargs, {'city': 'a-city'})

    def test_invalid_resolve(self):
        test_urls = [
            '/lookahead-/not-a-city/',
            '/lookbehind-/not-a-city/',
            '/lookahead+/other-city/',
            '/lookbehind+/other-city/',
        ]
        for test_url in test_urls:
            with self.subTest(url=test_url):
                with self.assertRaises(Resolver404):
                    resolve(test_url)

    def test_valid_reverse(self):
        test_urls = [
            ('lookahead-positive', {'city': 'a-city'}, '/lookahead+/a-city/'),
            ('lookahead-negative', {'city': 'a-city'}, '/lookahead-/a-city/'),
            ('lookbehind-positive', {'city': 'a-city'}, '/lookbehind+/a-city/'),
            ('lookbehind-negative', {'city': 'a-city'}, '/lookbehind-/a-city/'),
        ]
        for name, kwargs, expected in test_urls:
            with self.subTest(name=name, kwargs=kwargs):
                self.assertEqual(reverse(name, kwargs=kwargs), expected)

    def test_invalid_reverse(self):
        test_urls = [
            ('lookahead-positive', {'city': 'other-city'}),
            ('lookahead-negative', {'city': 'not-a-city'}),
            ('lookbehind-positive', {'city': 'other-city'}),
            ('lookbehind-negative', {'city': 'not-a-city'}),
        ]
        for name, kwargs in test_urls:
            with self.subTest(name=name, kwargs=kwargs):
                with self.assertRaises(NoReverseMatch):
                    reverse(name, kwargs=kwargs)