tests.py

from datetime import datetime
from operator import attrgetter
from django.core.exceptions import FieldError
from django.db import connection
from django.test import TestCase, skipUnlessDBFeature
from models import Author, Article, Tag

from bson.objectid import ObjectId


class LookupTests(TestCase):

    #def setUp(self):
    def setUp(self):
        # Create a few Authors.
        self.au1 = Author(name='Author 1')
        self.au1.save()
        self.au2 = Author(name='Author 2')
        self.au2.save()
        # Create a couple of Articles.
        self.a1 = Article(headline='Article 1', pub_date=datetime(2005, 7, 26), author=self.au1)
        self.a1.save()
        self.a2 = Article(headline='Article 2', pub_date=datetime(2005, 7, 27), author=self.au1)
        self.a2.save()
        self.a3 = Article(headline='Article 3', pub_date=datetime(2005, 7, 27), author=self.au1)
        self.a3.save()
        self.a4 = Article(headline='Article 4', pub_date=datetime(2005, 7, 28), author=self.au1)
        self.a4.save()
        self.a5 = Article(headline='Article 5', pub_date=datetime(2005, 8, 1, 9, 0), author=self.au2)
        self.a5.save()
        self.a6 = Article(headline='Article 6', pub_date=datetime(2005, 8, 1, 8, 0), author=self.au2)
        self.a6.save()
        self.a7 = Article(headline='Article 7', pub_date=datetime(2005, 7, 27), author=self.au2)
        self.a7.save()
        # Create a few Tags.
        self.t1 = Tag(name='Tag 1')
        self.t1.save()
        self.t1.articles.add(self.a1, self.a2, self.a3)
        self.t2 = Tag(name='Tag 2')
        self.t2.save()
        self.t2.articles.add(self.a3, self.a4, self.a5)
        self.t3 = Tag(name='Tag 3')
        self.t3.save()
        self.t3.articles.add(self.a5, self.a6, self.a7)

    def test_exists(self):
        # We can use .exists() to check that there are some
        self.assertTrue(Article.objects.exists())
        for a in Article.objects.all():
            a.delete()
        # There should be none now!
        self.assertFalse(Article.objects.exists())

    @skipUnlessDBFeature('supports_date_lookup_using_string')
    def test_lookup_date_as_str(self):
        # A date lookup can be performed using a string search
        self.assertQuerysetEqual(Article.objects.filter(pub_date__startswith='2005'),
            [
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 7>',
                '<Article: Article 1>',
            ])

    def test_iterator(self):
        # Each QuerySet gets iterator(), which is a generator that "lazily"
        # returns results using database-level iteration.
        self.assertQuerysetEqual(Article.objects.iterator(),
            [
                'Article 5',
                'Article 6',
                'Article 4',
                'Article 2',
                'Article 3',
                'Article 7',
                'Article 1',
            ],
            transform=attrgetter('headline'))
        # iterator() can be used on any QuerySet.
        self.assertQuerysetEqual(
            Article.objects.filter(headline__endswith='4').iterator(),
            ['Article 4'],
            transform=attrgetter('headline'))

    def test_count(self):
        # count() returns the number of objects matching search criteria.
        self.assertEqual(Article.objects.count(), 7)
        self.assertEqual(Article.objects.filter(pub_date__exact=datetime(2005, 7, 27)).count(), 3)
        self.assertEqual(Article.objects.filter(headline__startswith='Blah blah').count(), 0)

        # count() should respect sliced query sets.
        articles = Article.objects.all()
        self.assertEqual(articles.count(), 7)
        self.assertEqual(articles[:4].count(), 4)
        self.assertEqual(articles[1:100].count(), 6)
        self.assertEqual(articles[10:100].count(), 0)

        # Date and date/time lookups can also be done with strings.
        self.assertEqual(Article.objects.filter(pub_date__exact='2005-07-27 00:00:00').count(), 3)

    def test_in_bulk(self):
        # in_bulk() takes a list of IDs and returns a dictionary mapping IDs to objects.
        arts = Article.objects.in_bulk([self.a1.id, self.a2.id])
        self.assertEqual(arts[self.a1.id], self.a1)
        self.assertEqual(arts[self.a2.id], self.a2)
        self.assertEqual(Article.objects.in_bulk([self.a3.id]), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk(set([self.a3.id])), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk(frozenset([self.a3.id])), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk((self.a3.id,)), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk([ObjectId()]), {})
        self.assertEqual(Article.objects.in_bulk([]), {})
        self.assertRaises(AssertionError, Article.objects.in_bulk, 'foo')
        self.assertRaises(TypeError, Article.objects.in_bulk)
        self.assertRaises(TypeError, Article.objects.in_bulk, headline__startswith='Blah')

    def test_values(self):
        # values() returns a list of dictionaries instead of object instances --
        # and you can specify which fields you want to retrieve.
        identity = lambda x:x
        self.assertQuerysetEqual(Article.objects.values('headline'),
            [
                {'headline': u'Article 5'},
                {'headline': u'Article 6'},
                {'headline': u'Article 4'},
                {'headline': u'Article 2'},
                {'headline': u'Article 3'},
                {'headline': u'Article 7'},
                {'headline': u'Article 1'},
            ],
            transform=identity)
        self.assertQuerysetEqual(
            Article.objects.filter(pub_date__exact=datetime(2005, 7, 27)).values('id'),
            [{'id': self.a2.id}, {'id': self.a3.id}, {'id': self.a7.id}],
            transform=identity)
        self.assertQuerysetEqual(Article.objects.values('id', 'headline'),
            [
                {'id': self.a5.id, 'headline': 'Article 5'},
                {'id': self.a6.id, 'headline': 'Article 6'},
                {'id': self.a4.id, 'headline': 'Article 4'},
                {'id': self.a2.id, 'headline': 'Article 2'},
                {'id': self.a3.id, 'headline': 'Article 3'},
                {'id': self.a7.id, 'headline': 'Article 7'},
                {'id': self.a1.id, 'headline': 'Article 1'},
            ],
            transform=identity)
        # You can use values() with iterator() for memory savings,
        # because iterator() uses database-level iteration.
        self.assertQuerysetEqual(Article.objects.values('id', 'headline').iterator(),
            [
                {'headline': u'Article 5', 'id': self.a5.id},
                {'headline': u'Article 6', 'id': self.a6.id},
                {'headline': u'Article 4', 'id': self.a4.id},
                {'headline': u'Article 2', 'id': self.a2.id},
                {'headline': u'Article 3', 'id': self.a3.id},
                {'headline': u'Article 7', 'id': self.a7.id},
                {'headline': u'Article 1', 'id': self.a1.id},
            ],
            transform=identity)

    def test_values_list(self):
        # values_list() is similar to values(), except that the results are
        # returned as a list of tuples, rather than a list of dictionaries.
        # Within each tuple, the order of the elemnts is the same as the order
        # of fields in the values_list() call.
        identity = lambda x:x
        self.assertQuerysetEqual(Article.objects.values_list('headline'),
            [
                (u'Article 5',),
                (u'Article 6',),
                (u'Article 4',),
                (u'Article 2',),
                (u'Article 3',),
                (u'Article 7',),
                (u'Article 1',),
            ], transform=identity)
        self.assertQuerysetEqual(Article.objects.values_list('id').order_by('id'),
            [(self.a1.id,), (self.a2.id,), (self.a3.id,), (self.a4.id,), (self.a5.id,), (self.a6.id,), (self.a7.id,)],
            transform=identity)
        self.assertQuerysetEqual(
            Article.objects.values_list('id', flat=True).order_by('id'),
            [self.a1.id, self.a2.id, self.a3.id, self.a4.id, self.a5.id, self.a6.id, self.a7.id],
            transform=identity)
        self.assertRaises(TypeError, Article.objects.values_list, 'id', 'headline', flat=True)

    def test_get_next_previous_by(self):
        # Every DateField and DateTimeField creates get_next_by_FOO() and
        # get_previous_by_FOO() methods. In the case of identical date values,
        # these methods will use the ID as a fallback check. This guarantees
        # that no records are skipped or duplicated.
        self.assertEqual(repr(self.a1.get_next_by_pub_date()),
                         '<Article: Article 2>')
        self.assertEqual(repr(self.a2.get_next_by_pub_date()),
                         '<Article: Article 3>')
        self.assertEqual(repr(self.a2.get_next_by_pub_date(headline__endswith='6')),
                         '<Article: Article 6>')
        self.assertEqual(repr(self.a3.get_next_by_pub_date()),
                         '<Article: Article 7>')
        self.assertEqual(repr(self.a4.get_next_by_pub_date()),
                         '<Article: Article 6>')
        self.assertRaises(Article.DoesNotExist, self.a5.get_next_by_pub_date)
        self.assertEqual(repr(self.a6.get_next_by_pub_date()),
                         '<Article: Article 5>')
        self.assertEqual(repr(self.a7.get_next_by_pub_date()),
                         '<Article: Article 4>')

        self.assertEqual(repr(self.a7.get_previous_by_pub_date()),
                         '<Article: Article 3>')
        self.assertEqual(repr(self.a6.get_previous_by_pub_date()),
                         '<Article: Article 4>')
        self.assertEqual(repr(self.a5.get_previous_by_pub_date()),
                         '<Article: Article 6>')
        self.assertEqual(repr(self.a4.get_previous_by_pub_date()),
                         '<Article: Article 7>')
        self.assertEqual(repr(self.a3.get_previous_by_pub_date()),
                         '<Article: Article 2>')
        self.assertEqual(repr(self.a2.get_previous_by_pub_date()),
                         '<Article: Article 1>')

    def test_escaping(self):
        # Underscores, percent signs and backslashes have special meaning in the
        # underlying SQL code, but Django handles the quoting of them automatically.
        a8 = Article(headline='Article_ with underscore', pub_date=datetime(2005, 11, 20))
        a8.save()
        self.assertQuerysetEqual(Article.objects.filter(headline__startswith='Article'),
            [
                '<Article: Article_ with underscore>',
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 7>',
                '<Article: Article 1>',
            ])
        self.assertQuerysetEqual(Article.objects.filter(headline__startswith='Article_'),
                                 ['<Article: Article_ with underscore>'])
        a9 = Article(headline='Article% with percent sign', pub_date=datetime(2005, 11, 21))
        a9.save()
        self.assertQuerysetEqual(Article.objects.filter(headline__startswith='Article'),
            [
                '<Article: Article% with percent sign>',
                '<Article: Article_ with underscore>',
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 7>',
                '<Article: Article 1>',
            ])
        self.assertQuerysetEqual(Article.objects.filter(headline__startswith='Article%'),
                                 ['<Article: Article% with percent sign>'])
        a10 = Article(headline='Article with \\ backslash', pub_date=datetime(2005, 11, 22))
        a10.save()
        self.assertQuerysetEqual(Article.objects.filter(headline__contains='\\'),
                                 ['<Article: Article with \ backslash>'])

    def test_exclude(self):
        a8 = Article.objects.create(headline='Article_ with underscore', pub_date=datetime(2005, 11, 20))
        a9 = Article.objects.create(headline='Article% with percent sign', pub_date=datetime(2005, 11, 21))
        a10 = Article.objects.create(headline='Article with \\ backslash', pub_date=datetime(2005, 11, 22))

        # exclude() is the opposite of filter() when doing lookups:
        self.assertQuerysetEqual(
            Article.objects.filter(headline__contains='Article').exclude(headline__contains='with'),
            [
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 7>',
                '<Article: Article 1>',
            ])
        self.assertQuerysetEqual(Article.objects.exclude(headline__startswith="Article_"),
            [
                '<Article: Article with \\ backslash>',
                '<Article: Article% with percent sign>',
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 7>',
                '<Article: Article 1>',
            ])
        self.assertQuerysetEqual(Article.objects.exclude(headline="Article 7"),
            [
                '<Article: Article with \\ backslash>',
                '<Article: Article% with percent sign>',
                '<Article: Article_ with underscore>',
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 1>',
            ])

    def test_none(self):
       # none() returns an EmptyQuerySet that behaves like any other QuerySet object
        self.assertQuerysetEqual(Article.objects.none(), [])
        self.assertQuerysetEqual(
            Article.objects.none().filter(headline__startswith='Article'), [])
        self.assertQuerysetEqual(
            Article.objects.filter(headline__startswith='Article').none(), [])
        self.assertEqual(Article.objects.none().count(), 0)
        self.assertEqual(
            Article.objects.none().update(headline="This should not take effect"), 0)
        self.assertQuerysetEqual(
            [article for article in Article.objects.none().iterator()],
            [])

    def test_in(self):
        # using __in with an empty list should return an empty query set
        self.assertQuerysetEqual(Article.objects.filter(id__in=[]), [])
        self.assertQuerysetEqual(Article.objects.exclude(id__in=[]),
            [
                '<Article: Article 5>',
                '<Article: Article 6>',
                '<Article: Article 4>',
                '<Article: Article 2>',
                '<Article: Article 3>',
                '<Article: Article 7>',
                '<Article: Article 1>',
            ])

    def test_error_messages(self):
        # Programming errors are pointed out with nice error messages
        try:
            Article.objects.filter(pub_date_year='2005').count()
            self.fail('FieldError not raised')
        except FieldError, ex:
            self.assertEqual(str(ex), "Cannot resolve keyword 'pub_date_year' "
                             "into field. Choices are: author, headline, id, pub_date, tag")
        try:
            Article.objects.filter(headline__starts='Article')
            self.fail('FieldError not raised')
        except FieldError, ex:
            self.assertEqual(str(ex), "Join on field 'headline' not permitted. "
                             "Did you misspell 'starts' for the lookup type?")

    def test_regex(self):
        # Create some articles with a bit more interesting headlines for testing field lookups:
        for a in Article.objects.all():
            a.delete()
        now = datetime.now()
        a1 = Article(pub_date=now, headline='f')
        a1.save()
        a2 = Article(pub_date=now, headline='fo')
        a2.save()
        a3 = Article(pub_date=now, headline='foo')
        a3.save()
        a4 = Article(pub_date=now, headline='fooo')
        a4.save()
        a5 = Article(pub_date=now, headline='hey-Foo')
        a5.save()
        a6 = Article(pub_date=now, headline='bar')
        a6.save()
        a7 = Article(pub_date=now, headline='AbBa')
        a7.save()
        a8 = Article(pub_date=now, headline='baz')
        a8.save()
        a9 = Article(pub_date=now, headline='baxZ')
        a9.save()
        # zero-or-more
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'fo*'),
            ['<Article: f>', '<Article: fo>', '<Article: foo>', '<Article: fooo>'])
        self.assertQuerysetEqual(Article.objects.filter(headline__iregex=r'fo*'),
            [
                '<Article: f>',
                '<Article: fo>',
                '<Article: foo>',
                '<Article: fooo>',
                '<Article: hey-Foo>',
            ])
        # one-or-more
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'fo+'),
            ['<Article: fo>', '<Article: foo>', '<Article: fooo>'])
        # wildcard
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'fooo?'),
            ['<Article: foo>', '<Article: fooo>'])
        # leading anchor
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'^b'),
            ['<Article: bar>', '<Article: baxZ>', '<Article: baz>'])
        self.assertQuerysetEqual(Article.objects.filter(headline__iregex=r'^a'),
            ['<Article: AbBa>'])
        # trailing anchor
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'z$'),
            ['<Article: baz>'])
        self.assertQuerysetEqual(Article.objects.filter(headline__iregex=r'z$'),
            ['<Article: baxZ>', '<Article: baz>'])
        # character sets
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'ba[rz]'),
            ['<Article: bar>', '<Article: baz>'])
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'ba.[RxZ]'),
            ['<Article: baxZ>'])
        self.assertQuerysetEqual(Article.objects.filter(headline__iregex=r'ba[RxZ]'),
            ['<Article: bar>', '<Article: baxZ>', '<Article: baz>'])

        # and more articles:
        a10 = Article(pub_date=now, headline='foobar')
        a10.save()
        a11 = Article(pub_date=now, headline='foobaz')
        a11.save()
        a12 = Article(pub_date=now, headline='ooF')
        a12.save()
        a13 = Article(pub_date=now, headline='foobarbaz')
        a13.save()
        a14 = Article(pub_date=now, headline='zoocarfaz')
        a14.save()
        a15 = Article(pub_date=now, headline='barfoobaz')
        a15.save()
        a16 = Article(pub_date=now, headline='bazbaRFOO')
        a16.save()

        # alternation
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'oo(f|b)'),
            [
                '<Article: barfoobaz>',
                '<Article: foobar>',
                '<Article: foobarbaz>',
                '<Article: foobaz>',
            ])
        self.assertQuerysetEqual(Article.objects.filter(headline__iregex=r'oo(f|b)'),
            [
                '<Article: barfoobaz>',
                '<Article: foobar>',
                '<Article: foobarbaz>',
                '<Article: foobaz>',
                '<Article: ooF>',
            ])
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'^foo(f|b)'),
            ['<Article: foobar>', '<Article: foobarbaz>', '<Article: foobaz>'])

        # greedy matching
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'b.*az'),
            [
                '<Article: barfoobaz>',
                '<Article: baz>',
                '<Article: bazbaRFOO>',
                '<Article: foobarbaz>',
                '<Article: foobaz>',
            ])
        self.assertQuerysetEqual(Article.objects.filter(headline__iregex=r'b.*ar'),
            [
                '<Article: bar>',
                '<Article: barfoobaz>',
                '<Article: bazbaRFOO>',
                '<Article: foobar>',
                '<Article: foobarbaz>',
            ])

    @skipUnlessDBFeature('supports_regex_backreferencing')
    def test_regex_backreferencing(self):
        # grouping and backreferences
        now = datetime.now()
        a10 = Article(pub_date=now, headline='foobar')
        a10.save()
        a11 = Article(pub_date=now, headline='foobaz')
        a11.save()
        a12 = Article(pub_date=now, headline='ooF')
        a12.save()
        a13 = Article(pub_date=now, headline='foobarbaz')
        a13.save()
        a14 = Article(pub_date=now, headline='zoocarfaz')
        a14.save()
        a15 = Article(pub_date=now, headline='barfoobaz')
        a15.save()
        a16 = Article(pub_date=now, headline='bazbaRFOO')
        a16.save()
        self.assertQuerysetEqual(Article.objects.filter(headline__regex=r'b(.).*b\1'),
            ['<Article: barfoobaz>', '<Article: bazbaRFOO>', '<Article: foobarbaz>'])