[1.2.X] Migrated the custom_managers tests. Thanks to Alex Gaynor.

Backport of r13774 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13791 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/modeltests/custom_managers/tests.py

@@ -0,0 +1,71 @@
+from django.test import TestCase
+
+from models import Person, Book, Car, PersonManager, PublishedBookManager
+
+
+class CustomManagerTests(TestCase):
+    def test_manager(self):
+        p1 = Person.objects.create(first_name="Bugs", last_name="Bunny", fun=True)
+        p2 = Person.objects.create(first_name="Droopy", last_name="Dog", fun=False)
+
+        self.assertQuerysetEqual(
+            Person.objects.get_fun_people(), [
+                "Bugs Bunny"
+            ],
+            unicode
+        )
+        # The RelatedManager used on the 'books' descriptor extends the default
+        # manager
+        self.assertTrue(isinstance(p2.books, PublishedBookManager))
+
+        b1 = Book.published_objects.create(
+            title="How to program", author="Rodney Dangerfield", is_published=True
+        )
+        b2 = Book.published_objects.create(
+            title="How to be smart", author="Albert Einstein", is_published=False
+        )
+
+        # The default manager, "objects", doesn't exist, because a custom one
+        # was provided.
+        self.assertRaises(AttributeError, lambda: Book.objects)
+
+        # The RelatedManager used on the 'authors' descriptor extends the
+        # default manager
+        self.assertTrue(isinstance(b2.authors, PersonManager))
+
+        self.assertQuerysetEqual(
+            Book.published_objects.all(), [
+                "How to program",
+            ],
+            lambda b: b.title
+        )
+
+        c1 = Car.cars.create(name="Corvette", mileage=21, top_speed=180)
+        c2 = Car.cars.create(name="Neon", mileage=31, top_speed=100)
+
+        self.assertQuerysetEqual(
+            Car.cars.order_by("name"), [
+                "Corvette",
+                "Neon",
+            ],
+            lambda c: c.name
+        )
+
+        self.assertQuerysetEqual(
+            Car.fast_cars.all(), [
+                "Corvette",
+            ],
+            lambda c: c.name
+        )
+
+        # Each model class gets a "_default_manager" attribute, which is a
+        # reference to the first manager defined in the class. In this case,
+        # it's "cars".
+
+        self.assertQuerysetEqual(
+            Car._default_manager.order_by("name"), [
+                "Corvette",
+                "Neon",
+            ],
+            lambda c: c.name
+        )