Refs #24299 -- Made contenttypes migrations signal handler more robust. (d392c1e1) · Commits · Dom Sekotill / django

django/contrib/contenttypes/models.py

+13 −12

Original line number	Diff line number	Diff line
		@@ -4,7 +4,7 @@ import warnings

		from django.apps import apps
		from django.db import models
		from django.db.utils import OperationalError, ProgrammingError
		from django.db.utils import IntegrityError, OperationalError, ProgrammingError
		from django.utils.deprecation import RemovedInDjango20Warning
		from django.utils.encoding import force_text, python_2_unicode_compatible
		from django.utils.translation import ugettext_lazy as _
		@@ -58,18 +58,11 @@ class ContentTypeManager(models.Manager):

		# The ContentType entry was not found in the cache, therefore we
		# proceed to load or create it.
		try:
		try:
		# We start with get() and not get_or_create() in order to use
		# the db_for_read (see #20401).
		ct = self.get(app_label=opts.app_label, model=opts.model_name)
		except (OperationalError, ProgrammingError):
		# It's possible to migrate a single app before contenttypes,
		# as it's not a required initial dependency (it's contrib!)
		# Have a nice error for this.
		raise RuntimeError(
		"Error creating new content types. Please make sure contenttypes "
		"is migrated before trying to migrate apps individually."
		)
		except self.model.DoesNotExist:
		# Not found in the database; we proceed to create it. This time we
		# use get_or_create to take care of any race conditions.
		@@ -77,6 +70,14 @@ class ContentTypeManager(models.Manager):
		app_label=opts.app_label,
		model=opts.model_name,
		)
		except (OperationalError, ProgrammingError, IntegrityError):
		# It's possible to migrate a single app before contenttypes,
		# as it's not a required initial dependency (it's contrib!)
		# Have a nice error for this.
		raise RuntimeError(
		"Error creating new content types. Please make sure contenttypes "
		"is migrated before trying to migrate apps individually."
		)
		self._add_to_cache(self.db, ct)
		return ct

django/contrib/contenttypes/tests/tests.py

+25 −1

Original line number	Diff line number	Diff line
		@@ -5,8 +5,9 @@ import warnings
		from django.contrib.contenttypes.models import ContentType
		from django.contrib.contenttypes.views import shortcut
		from django.contrib.sites.shortcuts import get_current_site
		from django.db.utils import IntegrityError, OperationalError, ProgrammingError
		from django.http import Http404, HttpRequest
		from django.test import TestCase, override_settings
		from django.test import TestCase, mock, override_settings
		from django.utils import six

		from .models import (
		@@ -264,3 +265,26 @@ class ContentTypesTests(TestCase):
		"ContentType.name field doesn't exist any longer. Please remove it from your code."
		)
		self.assertTrue(ContentType.objects.filter(model='OldModel').exists())

		@mock.patch('django.contrib.contenttypes.models.ContentTypeManager.get_or_create')
		@mock.patch('django.contrib.contenttypes.models.ContentTypeManager.get')
		def test_message_if_get_for_model_fails(self, mocked_get, mocked_get_or_create):
		"""
		Check that `RuntimeError` with nice error message is raised if
		`get_for_model` fails because of database errors.
		"""

		def _test_message(mocked_method):
		for ExceptionClass in (IntegrityError, OperationalError, ProgrammingError):
		mocked_method.side_effect = ExceptionClass
		with self.assertRaisesMessage(
		RuntimeError,
		"Error creating new content types. Please make sure contenttypes "
		"is migrated before trying to migrate apps individually."
		):
		ContentType.objects.get_for_model(ContentType)

		_test_message(mocked_get)

		mocked_get.side_effect = ContentType.DoesNotExist
		_test_message(mocked_get_or_create)