Refs #24215 -- Improved error message for unhandled lazy model operations. (25c157e4) · Commits · Dom Sekotill / django

django/db/migrations/state.py

+36 −3

Original line number	Diff line number	Diff line
		@@ -232,9 +232,42 @@ class StateApps(Apps):
		if ignore_swappable:
		pending_models -= {make_model_tuple(settings.AUTH_USER_MODEL)}
		if pending_models:
		msg = "Unhandled pending operations for models: %s"
		labels = (".".join(model_key) for model_key in self._pending_operations)
		raise ValueError(msg % ", ".join(labels))
		raise ValueError(self._pending_models_error(pending_models))

		def _pending_models_error(self, pending_models):
		"""
		Almost all internal uses of lazy operations are to resolve string model
		references in related fields. We can extract the fields from those
		operations and use them to provide a nicer error message.

		This will work for any function passed to lazy_related_operation() that
		has a keyword argument called 'field'.
		"""
		def extract_field(operation):
		# Expect a functools.partial() with a kwarg called 'field' applied.
		try:
		return operation.func.keywords['field']
		except (AttributeError, KeyError):
		return None

		def extract_field_names(operations):
		return (str(field) for field in map(extract_field, operations) if field)

		get_ops = self._pending_operations.__getitem__
		# Ordered list of pairs of the form
		# ((app_label, model_name), [field_name_1, field_name_2, ...])
		models_fields = sorted(
		(model_key, sorted(extract_field_names(get_ops(model_key))))
		for model_key in pending_models
		)

		def model_text(model_key, fields):
		field_list = ", ".join(fields)
		field_text = " (referred to by fields: %s)" % field_list if fields else ""
		return ("%s.%s" % model_key) + field_text

		msg = "Unhandled pending operations for models:"
		return "\n ".join([msg] + [model_text(*i) for i in models_fields])

		@contextmanager
		def bulk_update(self):

tests/migrations/test_state.py

+34 −4

Original line number	Diff line number	Diff line
		@@ -625,8 +625,16 @@ class StateTests(SimpleTestCase):
		app_label = "migrations"
		apps = new_apps

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

		class Meta:
		app_label = "migrations"
		apps = new_apps

		class Book(models.Model):
		author = models.ForeignKey(Author, models.CASCADE)
		publisher = models.ForeignKey(Publisher, models.CASCADE)

		class Meta:
		app_label = "migrations"
		@@ -642,20 +650,42 @@ class StateTests(SimpleTestCase):
		# 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(Publisher))
		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)
		self.assertEqual(len(project_state.apps.get_models()), 4)

		# now make an invalid one with a ForeignKey
		project_state = ProjectState()
		project_state.add_model(ModelState.from_model(Book))
		with self.assertRaises(ValueError):
		msg = (
		"Unhandled pending operations for models:\n"
		" migrations.author (referred to by fields: migrations.Book.author)\n"
		" migrations.publisher (referred to by fields: migrations.Book.publisher)"
		)
		with self.assertRaisesMessage(ValueError, msg):
		project_state.apps

		# and another with ManyToManyField
		# And another with ManyToManyField.
		project_state = ProjectState()
		project_state.add_model(ModelState.from_model(Magazine))
		with self.assertRaises(ValueError):
		msg = (
		"Unhandled pending operations for models:\n"
		" migrations.author (referred to by fields: "
		"migrations.Magazine.authors, migrations.Magazine_authors.author)"
		)
		with self.assertRaisesMessage(ValueError, msg):
		project_state.apps

		# And now with multiple models and multiple fields.
		project_state.add_model(ModelState.from_model(Book))
		msg = (
		"Unhandled pending operations for models:\n"
		" migrations.author (referred to by fields: migrations.Book.author, "
		"migrations.Magazine.authors, migrations.Magazine_authors.author)\n"
		" migrations.publisher (referred to by fields: migrations.Book.publisher)"
		)
		with self.assertRaisesMessage(ValueError, msg):
		project_state.apps

		def test_real_apps(self):