Fixed #25044 -- Fixed migrations for renaming ManyToManyField's through model. (f1e408ff) · Commits · Dom Sekotill / django

AUTHORS

+1 −0

Original line number	Diff line number	Diff line
		@@ -758,6 +758,7 @@ answer newbie questions, and generally made Django that much better:
		Vladimir Kuzma <vladimirkuzma.ch@gmail.com>
		Vlado <vlado@labath.org>
		Vsevolod Solovyov
		Vytis Banaitis <vytis.banaitis@gmail.com>
		wam-djangobug@wamber.net
		Wang Chun <wangchun@exoweb.net>
		Warren Smith <warren@wandrsmith.net>

django/db/migrations/autodetector.py

+7 −0

Original line number	Diff line number	Diff line
		@@ -867,6 +867,13 @@ class MigrationAutodetector(object):
		)
		if rename_key in self.renamed_models:
		new_field.remote_field.model = old_field.remote_field.model
		if hasattr(new_field, "remote_field") and getattr(new_field.remote_field, "through", None):
		rename_key = (
		new_field.remote_field.through._meta.app_label,
		new_field.remote_field.through._meta.model_name,
		)
		if rename_key in self.renamed_models:
		new_field.remote_field.through = old_field.remote_field.through
		old_field_dec = self.deep_deconstruct(old_field)
		new_field_dec = self.deep_deconstruct(new_field)
		if old_field_dec != new_field_dec:

django/db/migrations/operations/models.py

+22 −0

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		@@ -307,6 +307,28 @@ class RenameModel(ModelOperation):
		new_fields.append((name, field))
		state.models[related_key].fields = new_fields
		state.reload_model(*related_key)
		# Repoint M2Ms with through pointing to us
		related_models = {
		f.remote_field.model for f in model._meta.fields
		if getattr(f.remote_field, 'model', None)
		}
		model_name = '%s.%s' % (app_label, self.old_name)
		for related_model in related_models:
		if related_model == model:
		related_key = (app_label, self.new_name_lower)
		else:
		related_key = (related_model._meta.app_label, related_model._meta.model_name)
		new_fields = []
		changed = False
		for name, field in state.models[related_key].fields:
		if field.is_relation and field.many_to_many and field.remote_field.through == model_name:
		field = field.clone()
		field.remote_field.through = '%s.%s' % (app_label, self.new_name)
		changed = True
		new_fields.append((name, field))
		if changed:
		state.models[related_key].fields = new_fields
		state.reload_model(*related_key)
		state.reload_model(app_label, self.new_name_lower)

		def database_forwards(self, app_label, schema_editor, from_state, to_state):

tests/migrations/test_autodetector.py

+24 −0

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		@@ -259,6 +259,10 @@ class AutodetectorTests(TestCase):
		("id", models.AutoField(primary_key=True)),
		("publishers", models.ManyToManyField("testapp.Publisher", through="testapp.Contract")),
		])
		author_with_renamed_m2m_through = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("publishers", models.ManyToManyField("testapp.Publisher", through="testapp.Deal")),
		])
		author_with_former_m2m = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("publishers", models.CharField(max_length=100)),
		@@ -286,6 +290,11 @@ class AutodetectorTests(TestCase):
		("author", models.ForeignKey("testapp.Author", models.CASCADE)),
		("publisher", models.ForeignKey("testapp.Publisher", models.CASCADE)),
		])
		contract_renamed = ModelState("testapp", "Deal", [
		("id", models.AutoField(primary_key=True)),
		("author", models.ForeignKey("testapp.Author", models.CASCADE)),
		("publisher", models.ForeignKey("testapp.Publisher", models.CASCADE)),
		])
		publisher = ModelState("testapp", "Publisher", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=100)),
		@@ -848,6 +857,21 @@ class AutodetectorTests(TestCase):
		# no AlterField for the related field.
		self.assertNumberMigrations(changes, 'otherapp', 0)

		def test_rename_m2m_through_model(self):
		"""
		Tests autodetection of renamed models that are used in M2M relations as
		through models.
		"""
		# Make state
		before = self.make_project_state([self.author_with_m2m_through, self.publisher, self.contract])
		after = self.make_project_state([self.author_with_renamed_m2m_through, self.publisher, self.contract_renamed])
		autodetector = MigrationAutodetector(before, after, MigrationQuestioner({'ask_rename_model': True}))
		changes = autodetector._detect_changes()
		# Right number/type of migrations?
		self.assertNumberMigrations(changes, 'testapp', 1)
		self.assertOperationTypes(changes, 'testapp', 0, ['RenameModel'])
		self.assertOperationAttributes(changes, 'testapp', 0, 0, old_name='Contract', new_name='Deal')

		def test_rename_model_with_renamed_rel_field(self):
		"""
		Tests autodetection of renamed models while simultaneously renaming one

tests/migrations/test_operations.py

+41 −0

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		@@ -727,6 +727,47 @@ class OperationTests(OperationTestBase):
		self.assertEqual(Rider.objects.count(), 2)
		self.assertEqual(Pony._meta.get_field('riders').remote_field.through.objects.count(), 2)

		def test_rename_m2m_through_model(self):
		app_label = "test_rename_through"
		project_state = self.apply_operations(app_label, ProjectState(), operations=[
		migrations.CreateModel("Rider", fields=[
		("id", models.AutoField(primary_key=True)),
		]),
		migrations.CreateModel("Pony", fields=[
		("id", models.AutoField(primary_key=True)),
		]),
		migrations.CreateModel("PonyRider", fields=[
		("id", models.AutoField(primary_key=True)),
		("rider", models.ForeignKey("test_rename_through.Rider", models.CASCADE)),
		("pony", models.ForeignKey("test_rename_through.Pony", models.CASCADE)),
		]),
		migrations.AddField(
		"Pony",
		"riders",
		models.ManyToManyField("test_rename_through.Rider", through="test_rename_through.PonyRider"),
		),
		])
		Pony = project_state.apps.get_model(app_label, "Pony")
		Rider = project_state.apps.get_model(app_label, "Rider")
		PonyRider = project_state.apps.get_model(app_label, "PonyRider")
		pony = Pony.objects.create()
		rider = Rider.objects.create()
		PonyRider.objects.create(pony=pony, rider=rider)

		project_state = self.apply_operations(app_label, project_state, operations=[
		migrations.RenameModel("PonyRider", "PonyRider2"),
		])
		Pony = project_state.apps.get_model(app_label, "Pony")
		Rider = project_state.apps.get_model(app_label, "Rider")
		PonyRider = project_state.apps.get_model(app_label, "PonyRider2")
		pony = Pony.objects.first()
		rider = Rider.objects.create()
		PonyRider.objects.create(pony=pony, rider=rider)
		self.assertEqual(Pony.objects.count(), 1)
		self.assertEqual(Rider.objects.count(), 2)
		self.assertEqual(PonyRider.objects.count(), 2)
		self.assertEqual(pony.riders.count(), 2)

		def test_add_field(self):
		"""
		Tests the AddField operation.