Refs #18586 -- Split out long custom_columns lookup test into multiple tests.

class CustomColumnsTests(TestCase):

    def test_db_column(self):

    def setUp(self):

        a1 = Author.objects.create(first_name="John", last_name="Smith")

        a2 = Author.objects.create(first_name="Peter", last_name="Jones")

        art = Article.objects.create(headline="Django lets you build Web apps easily")

        art.authors = [a1, a2]

        # Although the table and column names on Author have been set to custom

        # values, nothing about using the Author model has changed...

        self.a1 = a1

        self.art = art

        # Query the available authors

    def test_query_all_available_authors(self):

        self.assertQuerysetEqual(

            Author.objects.all(), [

                "Peter Jones", "John Smith",

            ],

            six.text_type

        )

    def test_get_first_name(self):

        self.assertEqual(

            Author.objects.get(first_name__exact="John"),

            self.a1,

        )

    def test_filter_first_name(self):

        self.assertQuerysetEqual(

            Author.objects.filter(first_name__exact="John"), [

                "John Smith",

            ],

            six.text_type

        )

        self.assertEqual(

            Author.objects.get(first_name__exact="John"),

            a1,

        )

    def test_field_error(self):

        self.assertRaises(FieldError,

            lambda: Author.objects.filter(firstname__exact="John")

        )

        a = Author.objects.get(last_name__exact="Smith")

        a.first_name = "John"

        a.last_name = "Smith"

    def test_attribute_error(self):

        with self.assertRaises(AttributeError):

            self.a1.firstname

        self.assertRaises(AttributeError, lambda: a.firstname)

        self.assertRaises(AttributeError, lambda: a.last)

        with self.assertRaises(AttributeError):

            self.a1.last

        # Although the Article table uses a custom m2m table,

        # nothing about using the m2m relationship has changed...

        # Get all the authors for an article

    def test_get_all_authors_for_an_article(self):

        self.assertQuerysetEqual(

            art.authors.all(), [

            self.art.authors.all(), [

                "Peter Jones",

                "John Smith",

            ],

            six.text_type

        )

        # Get the articles for an author

    def test_get_all_articles_for_an_author(self):

        self.assertQuerysetEqual(

            a.article_set.all(), [

            self.a1.article_set.all(), [

                "Django lets you build Web apps easily",

            ],

            lambda a: a.headline

        )

        # Query the authors across the m2m relation

    def test_get_author_m2m_relation(self):

        self.assertQuerysetEqual(

            art.authors.filter(last_name='Jones'), [

            self.art.authors.filter(last_name='Jones'), [

                "Peter Jones"

            ],

            six.text_type