Fixed #24340 -- Added nested deconstruction for list, tuple and dict values (ff8a02ae) · Commits · Dom Sekotill / django

django/db/migrations/autodetector.py

+28 −14

Original line number	Diff line number	Diff line
		@@ -52,8 +52,20 @@ class MigrationAutodetector(object):
		Used for full comparison for rename/alter; sometimes a single-level
		deconstruction will not compare correctly.
		"""
		if not hasattr(obj, 'deconstruct') or isinstance(obj, type):
		if isinstance(obj, list):
		return [self.deep_deconstruct(value) for value in obj]
		elif isinstance(obj, tuple):
		return tuple(self.deep_deconstruct(value) for value in obj)
		elif isinstance(obj, dict):
		return {
		key: self.deep_deconstruct(value)
		for key, value in obj.items()
		}
		elif isinstance(obj, type):
		# If this is a type that implements 'deconstruct' as an instance method,
		# avoid treating this as being deconstructible itself - see #22951
		return obj
		elif hasattr(obj, 'deconstruct'):
		deconstructed = obj.deconstruct()
		if isinstance(obj, models.Field):
		# we have a field which also returns a name
		@@ -67,6 +79,8 @@ class MigrationAutodetector(object):
		for key, value in kwargs.items()
		},
		)
		else:
		return obj

		def only_relation_agnostic_fields(self, fields):
		"""

tests/migrations/test_autodetector.py

+208 −1

Original line number	Diff line number	Diff line
		@@ -17,8 +17,16 @@ class DeconstructableObject(object):
		A custom deconstructable object.
		"""

		def __init__(self, args, *kwargs):
		self.args = args
		self.kwargs = kwargs

		def deconstruct(self):
		return self.__module__ + '.' + self.__class__.__name__, [], {}
		return (
		self.__module__ + '.' + self.__class__.__name__,
		self.args,
		self.kwargs
		)


		class AutodetectorTests(TestCase):
		@@ -63,6 +71,104 @@ class AutodetectorTests(TestCase):
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=models.IntegerField())),
		])
		author_name_deconstructable_list_1 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=[DeconstructableObject(), 123])),
		])
		author_name_deconstructable_list_2 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=[DeconstructableObject(), 123])),
		])
		author_name_deconstructable_list_3 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=[DeconstructableObject(), 999])),
		])
		author_name_deconstructable_tuple_1 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=(DeconstructableObject(), 123))),
		])
		author_name_deconstructable_tuple_2 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=(DeconstructableObject(), 123))),
		])
		author_name_deconstructable_tuple_3 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=(DeconstructableObject(), 999))),
		])
		author_name_deconstructable_dict_1 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default={
		'item': DeconstructableObject(), 'otheritem': 123
		})),
		])
		author_name_deconstructable_dict_2 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default={
		'item': DeconstructableObject(), 'otheritem': 123
		})),
		])
		author_name_deconstructable_dict_3 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default={
		'item': DeconstructableObject(), 'otheritem': 999
		})),
		])
		author_name_nested_deconstructable_1 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=DeconstructableObject(
		DeconstructableObject(1),
		(DeconstructableObject('t1'), DeconstructableObject('t2'),),
		a=DeconstructableObject('A'),
		b=DeconstructableObject(B=DeconstructableObject('c')),
		))),
		])
		author_name_nested_deconstructable_2 = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=DeconstructableObject(
		DeconstructableObject(1),
		(DeconstructableObject('t1'), DeconstructableObject('t2'),),
		a=DeconstructableObject('A'),
		b=DeconstructableObject(B=DeconstructableObject('c')),
		))),
		])
		author_name_nested_deconstructable_changed_arg = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=DeconstructableObject(
		DeconstructableObject(1),
		(DeconstructableObject('t1'), DeconstructableObject('t2-changed'),),
		a=DeconstructableObject('A'),
		b=DeconstructableObject(B=DeconstructableObject('c')),
		))),
		])
		author_name_nested_deconstructable_extra_arg = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=DeconstructableObject(
		DeconstructableObject(1),
		(DeconstructableObject('t1'), DeconstructableObject('t2'),),
		None,
		a=DeconstructableObject('A'),
		b=DeconstructableObject(B=DeconstructableObject('c')),
		))),
		])
		author_name_nested_deconstructable_changed_kwarg = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=DeconstructableObject(
		DeconstructableObject(1),
		(DeconstructableObject('t1'), DeconstructableObject('t2'),),
		a=DeconstructableObject('A'),
		b=DeconstructableObject(B=DeconstructableObject('c-changed')),
		))),
		])
		author_name_nested_deconstructable_extra_kwarg = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		("name", models.CharField(max_length=200, default=DeconstructableObject(
		DeconstructableObject(1),
		(DeconstructableObject('t1'), DeconstructableObject('t2'),),
		a=DeconstructableObject('A'),
		b=DeconstructableObject(B=DeconstructableObject('c')),
		c=None,
		))),
		])
		author_custom_pk = ModelState("testapp", "Author", [("pk_field", models.IntegerField(primary_key=True))])
		author_with_biography_non_blank = ModelState("testapp", "Author", [
		("id", models.AutoField(primary_key=True)),
		@@ -1225,6 +1331,107 @@ class AutodetectorTests(TestCase):
		changes = autodetector._detect_changes()
		self.assertEqual(changes, {})

		def test_deconstructable_list(self):
		"""Nested deconstruction descends into lists."""
		# When lists contain items that deconstruct to identical values, those lists
		# should be considered equal for the purpose of detecting state changes
		# (even if the original items are unequal).
		before = self.make_project_state([self.author_name_deconstructable_list_1])
		after = self.make_project_state([self.author_name_deconstructable_list_2])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(changes, {})

		# Legitimate differences within the deconstructed lists should be reported
		# as a change
		before = self.make_project_state([self.author_name_deconstructable_list_1])
		after = self.make_project_state([self.author_name_deconstructable_list_3])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		def test_deconstructable_tuple(self):
		"""Nested deconstruction descends into tuples."""
		# When tuples contain items that deconstruct to identical values, those tuples
		# should be considered equal for the purpose of detecting state changes
		# (even if the original items are unequal).
		before = self.make_project_state([self.author_name_deconstructable_tuple_1])
		after = self.make_project_state([self.author_name_deconstructable_tuple_2])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(changes, {})

		# Legitimate differences within the deconstructed tuples should be reported
		# as a change
		before = self.make_project_state([self.author_name_deconstructable_tuple_1])
		after = self.make_project_state([self.author_name_deconstructable_tuple_3])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		def test_deconstructable_dict(self):
		"""Nested deconstruction descends into dict values."""
		# When dicts contain items whose values deconstruct to identical values,
		# those dicts should be considered equal for the purpose of detecting
		# state changes (even if the original values are unequal).
		before = self.make_project_state([self.author_name_deconstructable_dict_1])
		after = self.make_project_state([self.author_name_deconstructable_dict_2])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(changes, {})

		# Legitimate differences within the deconstructed dicts should be reported
		# as a change
		before = self.make_project_state([self.author_name_deconstructable_dict_1])
		after = self.make_project_state([self.author_name_deconstructable_dict_3])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		def test_nested_deconstructable_objects(self):
		"""
		Nested deconstruction is applied recursively to the args/kwargs of
		deconstructed objects.
		"""
		# If the items within a deconstructed object's args/kwargs have the same
		# deconstructed values - whether or not the items themselves are different
		# instances - then the object as a whole is regarded as unchanged.
		before = self.make_project_state([self.author_name_nested_deconstructable_1])
		after = self.make_project_state([self.author_name_nested_deconstructable_2])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(changes, {})

		# Differences that exist solely within the args list of a deconstructed object
		# should be reported as changes
		before = self.make_project_state([self.author_name_nested_deconstructable_1])
		after = self.make_project_state([self.author_name_nested_deconstructable_changed_arg])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		# Additional args should also be reported as a change
		before = self.make_project_state([self.author_name_nested_deconstructable_1])
		after = self.make_project_state([self.author_name_nested_deconstructable_extra_arg])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		# Differences that exist solely within the kwargs dict of a deconstructed object
		# should be reported as changes
		before = self.make_project_state([self.author_name_nested_deconstructable_1])
		after = self.make_project_state([self.author_name_nested_deconstructable_changed_kwarg])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		# Additional kwargs should also be reported as a change
		before = self.make_project_state([self.author_name_nested_deconstructable_1])
		after = self.make_project_state([self.author_name_nested_deconstructable_extra_kwarg])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		self.assertEqual(len(changes), 1)

		def test_deconstruct_type(self):
		"""
		#22951 -- Uninstanted classes with deconstruct are correctly returned