django/tests/migrations/test_state.py

from django.apps.registry import Apps
from django.db import models
from django.db.migrations.operations import RemoveField
from django.db.migrations.state import ProjectState, ModelState, InvalidBasesError
from django.test import TestCase

from .models import (FoodManager, FoodQuerySet, ModelWithCustomBase,
    NoMigrationFoodManager)


class StateTests(TestCase):
    """
    Tests state construction, rendering and modification by operations.
    """

    def test_create(self):
        """
        Tests making a ProjectState from an Apps
        """

        new_apps = Apps(["migrations"])

        class Author(models.Model):
            name = models.CharField(max_length=255)
            bio = models.TextField()
            age = models.IntegerField(blank=True, null=True)

            class Meta:
                app_label = "migrations"
                apps = new_apps
                unique_together = ["name", "bio"]
                index_together = ["bio", "age"]

        class AuthorProxy(Author):
            class Meta:
                app_label = "migrations"
                apps = new_apps
                proxy = True
                ordering = ["name"]

        class SubAuthor(Author):
            width = models.FloatField(null=True)

            class Meta:
                app_label = "migrations"
                apps = new_apps

        class Book(models.Model):
            title = models.CharField(max_length=1000)
            author = models.ForeignKey(Author)
            contributors = models.ManyToManyField(Author)

            class Meta:
                app_label = "migrations"
                apps = new_apps
                verbose_name = "tome"
                db_table = "test_tome"

        class Food(models.Model):

            food_mgr = FoodManager('a', 'b')
            food_qs = FoodQuerySet.as_manager()
            food_no_mgr = NoMigrationFoodManager('x', 'y')

            class Meta:
                app_label = "migrations"
                apps = new_apps

        class FoodNoManagers(models.Model):

            class Meta:
                app_label = "migrations"
                apps = new_apps

        class FoodNoDefaultManager(models.Model):

            food_no_mgr = NoMigrationFoodManager('x', 'y')
            food_mgr = FoodManager('a', 'b')
            food_qs = FoodQuerySet.as_manager()

            class Meta:
                app_label = "migrations"
                apps = new_apps

        mgr1 = FoodManager('a', 'b')
        mgr2 = FoodManager('x', 'y', c=3, d=4)

        class FoodOrderedManagers(models.Model):
            # The managers on this model should be ordered by their creation
            # counter and not by the order in model body

            food_no_mgr = NoMigrationFoodManager('x', 'y')
            food_mgr2 = mgr2
            food_mgr1 = mgr1

            class Meta:
                app_label = "migrations"
                apps = new_apps

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        author_proxy_state = project_state.models['migrations', 'authorproxy']
        sub_author_state = project_state.models['migrations', 'subauthor']
        book_state = project_state.models['migrations', 'book']
        food_state = project_state.models['migrations', 'food']
        food_no_managers_state = project_state.models['migrations', 'foodnomanagers']
        food_no_default_manager_state = project_state.models['migrations', 'foodnodefaultmanager']
        food_order_manager_state = project_state.models['migrations', 'foodorderedmanagers']

        self.assertEqual(author_state.app_label, "migrations")
        self.assertEqual(author_state.name, "Author")
        self.assertEqual([x for x, y in author_state.fields], ["id", "name", "bio", "age"])
        self.assertEqual(author_state.fields[1][1].max_length, 255)
        self.assertEqual(author_state.fields[2][1].null, False)
        self.assertEqual(author_state.fields[3][1].null, True)
        self.assertEqual(author_state.options, {"unique_together": {("name", "bio")}, "index_together": {("bio", "age")}})
        self.assertEqual(author_state.bases, (models.Model, ))

        self.assertEqual(book_state.app_label, "migrations")
        self.assertEqual(book_state.name, "Book")
        self.assertEqual([x for x, y in book_state.fields], ["id", "title", "author", "contributors"])
        self.assertEqual(book_state.fields[1][1].max_length, 1000)
        self.assertEqual(book_state.fields[2][1].null, False)
        self.assertEqual(book_state.fields[3][1].__class__.__name__, "ManyToManyField")
        self.assertEqual(book_state.options, {"verbose_name": "tome", "db_table": "test_tome"})
        self.assertEqual(book_state.bases, (models.Model, ))

        self.assertEqual(author_proxy_state.app_label, "migrations")
        self.assertEqual(author_proxy_state.name, "AuthorProxy")
        self.assertEqual(author_proxy_state.fields, [])
        self.assertEqual(author_proxy_state.options, {"proxy": True, "ordering": ["name"]})
        self.assertEqual(author_proxy_state.bases, ("migrations.author", ))

        self.assertEqual(sub_author_state.app_label, "migrations")
        self.assertEqual(sub_author_state.name, "SubAuthor")
        self.assertEqual(len(sub_author_state.fields), 2)
        self.assertEqual(sub_author_state.bases, ("migrations.author", ))

        # The default manager is used in migrations
        self.assertEqual([name for name, mgr in food_state.managers], ['food_mgr'])
        self.assertEqual(food_state.managers[0][1].args, ('a', 'b', 1, 2))

        # No explicit managers defined. Migrations will fall back to the default
        self.assertEqual(food_no_managers_state.managers, [])

        # food_mgr is used in migration but isn't the default mgr, hence add the
        # default
        self.assertEqual([name for name, mgr in food_no_default_manager_state.managers],
                         ['food_no_mgr', 'food_mgr'])
        self.assertEqual(food_no_default_manager_state.managers[0][1].__class__, models.Manager)
        self.assertIsInstance(food_no_default_manager_state.managers[1][1], FoodManager)

        self.assertEqual([name for name, mgr in food_order_manager_state.managers],
                         ['food_mgr1', 'food_mgr2'])
        self.assertEqual([mgr.args for name, mgr in food_order_manager_state.managers],
                         [('a', 'b', 1, 2), ('x', 'y', 3, 4)])

    def test_render(self):
        """
        Tests rendering a ProjectState into an Apps.
        """
        project_state = ProjectState()
        project_state.add_model(ModelState(
            app_label="migrations",
            name="Tag",
            fields=[
                ("id", models.AutoField(primary_key=True)),
                ("name", models.CharField(max_length=100)),
                ("hidden", models.BooleanField()),
            ],
        ))
        project_state.add_model(ModelState(
            app_label="migrations",
            name="SubTag",
            fields=[
                ('tag_ptr', models.OneToOneField(
                    auto_created=True,
                    primary_key=True,
                    to_field='id',
                    serialize=False,
                    to='migrations.Tag',
                )),
                ("awesome", models.BooleanField()),
            ],
            bases=("migrations.Tag",),
        ))

        base_mgr = models.Manager()
        mgr1 = FoodManager('a', 'b')
        mgr2 = FoodManager('x', 'y', c=3, d=4)
        project_state.add_model(ModelState(
            app_label="migrations",
            name="Food",
            fields=[
                ("id", models.AutoField(primary_key=True)),
            ],
            managers=[
                # The ordering we really want is objects, mgr1, mgr2
                ('default', base_mgr),
                ('food_mgr2', mgr2),
                ('food_mgr1', mgr1),
            ]
        ))

        new_apps = project_state.apps
        self.assertEqual(new_apps.get_model("migrations", "Tag")._meta.get_field("name").max_length, 100)
        self.assertEqual(new_apps.get_model("migrations", "Tag")._meta.get_field("hidden").null, False)

        self.assertEqual(len(new_apps.get_model("migrations", "SubTag")._meta.local_fields), 2)

        Food = new_apps.get_model("migrations", "Food")
        managers = sorted(Food._meta.managers)
        self.assertEqual([mgr.name for _, mgr, _ in managers],
                         ['default', 'food_mgr1', 'food_mgr2'])
        self.assertEqual([mgr.__class__ for _, mgr, _ in managers],
                         [models.Manager, FoodManager, FoodManager])
        self.assertIs(managers[0][1], Food._default_manager)

    def test_render_model_inheritance(self):
        class Book(models.Model):
            title = models.CharField(max_length=1000)

            class Meta:
                app_label = "migrations"
                apps = Apps()

        class Novel(Book):
            class Meta:
                app_label = "migrations"
                apps = Apps()

        # First, test rendering individually
        apps = Apps(["migrations"])

        # We shouldn't be able to render yet
        ms = ModelState.from_model(Novel)
        with self.assertRaises(InvalidBasesError):
            ms.render(apps)

        # Once the parent model is in the app registry, it should be fine
        ModelState.from_model(Book).render(apps)
        ModelState.from_model(Novel).render(apps)

    def test_render_model_with_multiple_inheritance(self):
        class Foo(models.Model):
            class Meta:
                app_label = "migrations"
                apps = Apps()

        class Bar(models.Model):
            class Meta:
                app_label = "migrations"
                apps = Apps()

        class FooBar(Foo, Bar):
            class Meta:
                app_label = "migrations"
                apps = Apps()

        class AbstractSubFooBar(FooBar):
            class Meta:
                abstract = True
                apps = Apps()

        class SubFooBar(AbstractSubFooBar):
            class Meta:
                app_label = "migrations"
                apps = Apps()

        apps = Apps(["migrations"])

        # We shouldn't be able to render yet
        ms = ModelState.from_model(FooBar)
        with self.assertRaises(InvalidBasesError):
            ms.render(apps)

        # Once the parent models are in the app registry, it should be fine
        ModelState.from_model(Foo).render(apps)
        self.assertSequenceEqual(ModelState.from_model(Foo).bases, [models.Model])
        ModelState.from_model(Bar).render(apps)
        self.assertSequenceEqual(ModelState.from_model(Bar).bases, [models.Model])
        ModelState.from_model(FooBar).render(apps)
        self.assertSequenceEqual(ModelState.from_model(FooBar).bases, ['migrations.foo', 'migrations.bar'])
        ModelState.from_model(SubFooBar).render(apps)
        self.assertSequenceEqual(ModelState.from_model(SubFooBar).bases, ['migrations.foobar'])

    def test_render_project_dependencies(self):
        """
        Tests that the ProjectState render method correctly renders models
        to account for inter-model base dependencies.
        """
        new_apps = Apps()

        class A(models.Model):
            class Meta:
                app_label = "migrations"
                apps = new_apps

        class B(A):
            class Meta:
                app_label = "migrations"
                apps = new_apps

        class C(B):
            class Meta:
                app_label = "migrations"
                apps = new_apps

        class D(A):
            class Meta:
                app_label = "migrations"
                apps = new_apps

        class E(B):
            class Meta:
                app_label = "migrations"
                apps = new_apps
                proxy = True

        class F(D):
            class Meta:
                app_label = "migrations"
                apps = new_apps
                proxy = True

        # Make a ProjectState and render it
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(A))
        project_state.add_model(ModelState.from_model(B))
        project_state.add_model(ModelState.from_model(C))
        project_state.add_model(ModelState.from_model(D))
        project_state.add_model(ModelState.from_model(E))
        project_state.add_model(ModelState.from_model(F))
        final_apps = project_state.apps
        self.assertEqual(len(final_apps.get_models()), 6)

        # Now make an invalid ProjectState and make sure it fails
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(A))
        project_state.add_model(ModelState.from_model(B))
        project_state.add_model(ModelState.from_model(C))
        project_state.add_model(ModelState.from_model(F))
        with self.assertRaises(InvalidBasesError):
            project_state.apps

    def test_render_unique_app_labels(self):
        """
        Tests that the ProjectState render method doesn't raise an
        ImproperlyConfigured exception about unique labels if two dotted app
        names have the same last part.
        """
        class A(models.Model):
            class Meta:
                app_label = "django.contrib.auth"

        class B(models.Model):
            class Meta:
                app_label = "vendor.auth"

        # Make a ProjectState and render it
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(A))
        project_state.add_model(ModelState.from_model(B))
        self.assertEqual(len(project_state.apps.get_models()), 2)

    def test_equality(self):
        """
        Tests that == and != are implemented correctly.
        """

        # Test two things that should be equal
        project_state = ProjectState()
        project_state.add_model(ModelState(
            "migrations",
            "Tag",
            [
                ("id", models.AutoField(primary_key=True)),
                ("name", models.CharField(max_length=100)),
                ("hidden", models.BooleanField()),
            ],
            {},
            None,
        ))
        other_state = project_state.clone()
        self.assertEqual(project_state, project_state)
        self.assertEqual(project_state, other_state)
        self.assertEqual(project_state != project_state, False)
        self.assertEqual(project_state != other_state, False)

        # Make a very small change (max_len 99) and see if that affects it
        project_state = ProjectState()
        project_state.add_model(ModelState(
            "migrations",
            "Tag",
            [
                ("id", models.AutoField(primary_key=True)),
                ("name", models.CharField(max_length=99)),
                ("hidden", models.BooleanField()),
            ],
            {},
            None,
        ))
        self.assertNotEqual(project_state, other_state)
        self.assertEqual(project_state == other_state, False)

    def test_dangling_references_throw_error(self):
        new_apps = Apps()

        class Author(models.Model):
            name = models.TextField()

            class Meta:
                app_label = "migrations"
                apps = new_apps

        class Book(models.Model):
            author = models.ForeignKey(Author)

            class Meta:
                app_label = "migrations"
                apps = new_apps

        class Magazine(models.Model):
            authors = models.ManyToManyField(Author)

            class Meta:
                app_label = "migrations"
                apps = new_apps

        # Make a valid ProjectState and render it
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(Author))
        project_state.add_model(ModelState.from_model(Book))
        project_state.add_model(ModelState.from_model(Magazine))
        self.assertEqual(len(project_state.apps.get_models()), 3)

        # now make an invalid one with a ForeignKey
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(Book))
        with self.assertRaises(ValueError):
            project_state.apps

        # and another with ManyToManyField
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(Magazine))
        with self.assertRaises(ValueError):
            project_state.apps

    def test_real_apps(self):
        """
        Tests that including real apps can resolve dangling FK errors.
        This test relies on the fact that contenttypes is always loaded.
        """
        new_apps = Apps()

        class TestModel(models.Model):
            ct = models.ForeignKey("contenttypes.ContentType")

            class Meta:
                app_label = "migrations"
                apps = new_apps

        # If we just stick it into an empty state it should fail
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(TestModel))
        with self.assertRaises(ValueError):
            project_state.apps

        # If we include the real app it should succeed
        project_state = ProjectState(real_apps=["contenttypes"])
        project_state.add_model(ModelState.from_model(TestModel))
        rendered_state = project_state.apps
        self.assertEqual(
            len([x for x in rendered_state.get_models() if x._meta.app_label == "migrations"]),
            1,
        )

    def test_ignore_order_wrt(self):
        """
        Makes sure ProjectState doesn't include OrderWrt fields when
        making from existing models.
        """
        new_apps = Apps()

        class Author(models.Model):
            name = models.TextField()

            class Meta:
                app_label = "migrations"
                apps = new_apps

        class Book(models.Model):
            author = models.ForeignKey(Author)

            class Meta:
                app_label = "migrations"
                apps = new_apps
                order_with_respect_to = "author"

        # Make a valid ProjectState and render it
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(Author))
        project_state.add_model(ModelState.from_model(Book))
        self.assertEqual(
            [name for name, field in project_state.models["migrations", "book"].fields],
            ["id", "author"],
        )

    def test_manager_refer_correct_model_version(self):
        """
        #24147 - Tests that managers refer to the correct version of a
        historical model
        """
        project_state = ProjectState()
        project_state.add_model(ModelState(
            app_label="migrations",
            name="Tag",
            fields=[
                ("id", models.AutoField(primary_key=True)),
                ("hidden", models.BooleanField()),
            ],
            managers=[
                ('food_mgr', FoodManager('a', 'b')),
                ('food_qs', FoodQuerySet.as_manager()),
            ]
        ))

        old_model = project_state.apps.get_model('migrations', 'tag')

        new_state = project_state.clone()
        operation = RemoveField("tag", "hidden")
        operation.state_forwards("migrations", new_state)

        new_model = new_state.apps.get_model('migrations', 'tag')

        self.assertIsNot(old_model, new_model)
        self.assertIs(old_model, old_model.food_mgr.model)
        self.assertIs(old_model, old_model.food_qs.model)
        self.assertIs(new_model, new_model.food_mgr.model)
        self.assertIs(new_model, new_model.food_qs.model)
        self.assertIsNot(old_model.food_mgr, new_model.food_mgr)
        self.assertIsNot(old_model.food_qs, new_model.food_qs)
        self.assertIsNot(old_model.food_mgr.model, new_model.food_mgr.model)
        self.assertIsNot(old_model.food_qs.model, new_model.food_qs.model)


class ModelStateTests(TestCase):
    def test_custom_model_base(self):
        state = ModelState.from_model(ModelWithCustomBase)
        self.assertEqual(state.bases, (models.Model,))

    def test_bound_field_sanity_check(self):
        field = models.CharField(max_length=1)
        field.model = models.Model
        with self.assertRaisesMessage(ValueError,
                'ModelState.fields cannot be bound to a model - "field" is.'):
            ModelState('app', 'Model', [('field', field)])

    def test_fields_immutability(self):
        """
        Tests that rendering a model state doesn't alter its internal fields.
        """
        apps = Apps()
        field = models.CharField(max_length=1)
        state = ModelState('app', 'Model', [('name', field)])
        Model = state.render(apps)
        self.assertNotEqual(Model._meta.get_field('name'), field)

    def test_repr(self):
        field = models.CharField(max_length=1)
        state = ModelState('app', 'Model', [('name', field)], bases=['app.A', 'app.B', 'app.C'])
        self.assertEqual(repr(state), "<ModelState: 'app.Model'>")

        project_state = ProjectState()
        project_state.add_model(state)
        with self.assertRaisesMessage(InvalidBasesError, "Cannot resolve bases for [<ModelState: 'app.Model'>]"):
            project_state.apps