Commit 47e4b86d authored by Andrew Godwin's avatar Andrew Godwin
Browse files

Autodetect field alters

parent 80bdf68d

django/db/migrations/autodetector.py

+14 −0
Original line number Diff line number Diff line
@@ -89,6 +89,20 @@ class MigrationAutodetector(object): 
                        name = field_name,

                    )

                )

            # The same fields

            for field_name in old_field_names.intersection(new_field_names):

                # Did the field change?

                old_field_dec = old_model_state.get_field_by_name(field_name).deconstruct()

                new_field_dec = new_model_state.get_field_by_name(field_name).deconstruct()

                if old_field_dec != new_field_dec:

                    self.add_to_migration(

                        app_label,

                        operations.AlterField(

                            model_name = model_name,

                            name = field_name,

                            field = new_model_state.get_field_by_name(field_name),

                        )

                    )

        # Alright, now add internal dependencies

        for app_label, migrations in self.migrations.items():

            for m1, m2 in zip(migrations, migrations[1:]):

django/db/migrations/state.py

+6 −0
Original line number Diff line number Diff line
@@ -126,3 +126,9 @@ class ModelState(object): 
            tuple(self.bases),

            body,

        )



    def get_field_by_name(self, name):

        for fname, field in self.fields:

            if fname == name:

                return field

        raise ValueError("No field called %s on model %s" % (name, self.name))

tests/migrations/test_autodetector.py

+18 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ class AutodetectorTests(TestCase): 


    author_empty = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True))])

    author_name = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True)), ("name", models.CharField(max_length=200))])

    author_name_longer = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True)), ("name", models.CharField(max_length=400))])

    other_pony = ModelState("otherapp", "Pony", [("id", models.AutoField(primary_key=True))])

    other_stable = ModelState("otherapp", "Stable", [("id", models.AutoField(primary_key=True))])

    third_thing = ModelState("thirdapp", "Thing", [("id", models.AutoField(primary_key=True))])
@@ -130,3 +131,20 @@ class AutodetectorTests(TestCase): 
        action = migration.operations[0]

        self.assertEqual(action.__class__.__name__, "RemoveField")

        self.assertEqual(action.name, "name")



    def test_alter_field(self):

        "Tests autodetection of new fields"

        # Make state

        before = self.make_project_state([self.author_name])

        after = self.make_project_state([self.author_name_longer])

        autodetector = MigrationAutodetector(before, after)

        changes = autodetector.changes()

        # Right number of migrations?

        self.assertEqual(len(changes['testapp']), 1)

        # Right number of actions?

        migration = changes['testapp'][0]

        self.assertEqual(len(migration.operations), 1)

        # Right action?

        action = migration.operations[0]

        self.assertEqual(action.__class__.__name__, "AlterField")

        self.assertEqual(action.name, "name")

tests/migrations/test_operations.py

+2 −2
Original line number Diff line number Diff line
@@ -173,8 +173,8 @@ class OperationTests(TestCase): 
        operation = migrations.AlterField("Pony", "pink", models.IntegerField(null=True))

        new_state = project_state.clone()

        operation.state_forwards("test_alfl", new_state)

        self.assertEqual([f for n, f in project_state.models["test_alfl", "pony"].fields if n == "pink"][0].null, False)

        self.assertEqual([f for n, f in new_state.models["test_alfl", "pony"].fields if n == "pink"][0].null, True)

        self.assertEqual(project_state.models["test_alfl", "pony"].get_field_by_name("pink").null, False)

        self.assertEqual(new_state.models["test_alfl", "pony"].get_field_by_name("pink").null, True)

        # Test the database alteration

        self.assertColumnNotNull("test_alfl_pony", "pink")

        with connection.schema_editor() as editor: