Refs #28478 -- Deprecated TestCase's allow_database_queries and multi_db in favor of databases.

tests/test_utils/test_deprecated_features.py

@@ -0,0 +1,64 @@
+from django.db import connections
+from django.db.utils import DEFAULT_DB_ALIAS
+from django.test import SimpleTestCase, TestCase, TransactionTestCase
+from django.utils.deprecation import RemovedInDjango31Warning
+
+
+class AllowDatabaseQueriesDeprecationTests(SimpleTestCase):
+    def test_enabled(self):
+        class AllowedDatabaseQueries(SimpleTestCase):
+            allow_database_queries = True
+        message = (
+            '`SimpleTestCase.allow_database_queries` is deprecated. Restrict '
+            'the databases available during the execution of '
+            'test_utils.test_deprecated_features.AllowDatabaseQueriesDeprecationTests.'
+            'test_enabled.<locals>.AllowedDatabaseQueries with the '
+            '`databases` attribute instead.'
+        )
+        with self.assertWarnsMessage(RemovedInDjango31Warning, message):
+            self.assertEqual(AllowedDatabaseQueries.databases, {'default'})
+
+    def test_explicitly_disabled(self):
+        class AllowedDatabaseQueries(SimpleTestCase):
+            allow_database_queries = False
+        message = (
+            '`SimpleTestCase.allow_database_queries` is deprecated. Restrict '
+            'the databases available during the execution of '
+            'test_utils.test_deprecated_features.AllowDatabaseQueriesDeprecationTests.'
+            'test_explicitly_disabled.<locals>.AllowedDatabaseQueries with '
+            'the `databases` attribute instead.'
+        )
+        with self.assertWarnsMessage(RemovedInDjango31Warning, message):
+            self.assertEqual(AllowedDatabaseQueries.databases, set())
+
+
+class MultiDbDeprecationTests(SimpleTestCase):
+    def test_transaction_test_case(self):
+        class MultiDbTestCase(TransactionTestCase):
+            multi_db = True
+        message = (
+            '`TransactionTestCase.multi_db` is deprecated. Databases '
+            'available during this test can be defined using '
+            'test_utils.test_deprecated_features.MultiDbDeprecationTests.'
+            'test_transaction_test_case.<locals>.MultiDbTestCase.databases.'
+        )
+        with self.assertWarnsMessage(RemovedInDjango31Warning, message):
+            self.assertEqual(MultiDbTestCase.databases, set(connections))
+        MultiDbTestCase.multi_db = False
+        with self.assertWarnsMessage(RemovedInDjango31Warning, message):
+            self.assertEqual(MultiDbTestCase.databases, {DEFAULT_DB_ALIAS})
+
+    def test_test_case(self):
+        class MultiDbTestCase(TestCase):
+            multi_db = True
+        message = (
+            '`TestCase.multi_db` is deprecated. Databases available during '
+            'this test can be defined using '
+            'test_utils.test_deprecated_features.MultiDbDeprecationTests.'
+            'test_test_case.<locals>.MultiDbTestCase.databases.'
+        )
+        with self.assertWarnsMessage(RemovedInDjango31Warning, message):
+            self.assertEqual(MultiDbTestCase.databases, set(connections))
+        MultiDbTestCase.multi_db = False
+        with self.assertWarnsMessage(RemovedInDjango31Warning, message):
+            self.assertEqual(MultiDbTestCase.databases, {DEFAULT_DB_ALIAS})

tests/test_utils/test_testcase.py

@@ -1,7 +1,7 @@
 from django.db import IntegrityError, transaction
 from django.test import TestCase, skipUnlessDBFeature
 
-from .models import PossessedCar
+from .models import Car, PossessedCar
 
 
 class TestTestCase(TestCase):
@@ -18,3 +18,12 @@ class TestTestCase(TestCase):
             car.delete()
         finally:
             self._rollback_atomics = rollback_atomics
+
+    def test_disallowed_database_queries(self):
+        message = (
+            "Database queries to 'other' are not allowed in this test. "
+            "Add 'other' to test_utils.test_testcase.TestTestCase.databases to "
+            "ensure proper test isolation and silence this failure."
+        )
+        with self.assertRaisesMessage(AssertionError, message):
+            Car.objects.using('other').get()

tests/test_utils/test_transactiontestcase.py

@@ -3,6 +3,8 @@ from unittest import mock
 from django.db import connections
 from django.test import TestCase, TransactionTestCase, override_settings
 
+from .models import Car
+
 
 class TestSerializedRollbackInhibitsPostMigrate(TransactionTestCase):
     """
@@ -32,9 +34,9 @@ class TestSerializedRollbackInhibitsPostMigrate(TransactionTestCase):
 
 
 @override_settings(DEBUG=True)  # Enable query logging for test_queries_cleared
-class TransactionTestCaseMultiDbTests(TestCase):
+class TransactionTestCaseDatabasesTests(TestCase):
     available_apps = []
-    multi_db = True
+    databases = {'default', 'other'}
 
     def test_queries_cleared(self):
         """
@@ -44,3 +46,17 @@ class TransactionTestCaseMultiDbTests(TestCase):
         """
         for alias in connections:
             self.assertEqual(len(connections[alias].queries_log), 0, 'Failed for alias %s' % alias)
+
+
+class DisallowedDatabaseQueriesTests(TransactionTestCase):
+    available_apps = ['test_utils']
+
+    def test_disallowed_database_queries(self):
+        message = (
+            "Database queries to 'other' are not allowed in this test. "
+            "Add 'other' to test_utils.test_transactiontestcase."
+            "DisallowedDatabaseQueriesTests.databases to ensure proper test "
+            "isolation and silence this failure."
+        )
+        with self.assertRaisesMessage(AssertionError, message):
+            Car.objects.using('other').get()

tests/test_utils/tests.py

@@ -7,8 +7,9 @@ from unittest import mock
 from django.conf import settings
 from django.contrib.staticfiles.finders import get_finder, get_finders
 from django.contrib.staticfiles.storage import staticfiles_storage
+from django.core.exceptions import ImproperlyConfigured
 from django.core.files.storage import default_storage
-from django.db import connection, models, router
+from django.db import connection, connections, models, router
 from django.forms import EmailField, IntegerField
 from django.http import HttpResponse
 from django.template.loader import render_to_string
@@ -1160,32 +1161,67 @@ class TestBadSetUpTestData(TestCase):
 class DisallowedDatabaseQueriesTests(SimpleTestCase):
     def test_disallowed_database_queries(self):
         expected_message = (
-            "Database queries aren't allowed in SimpleTestCase. "
-            "Either use TestCase or TransactionTestCase to ensure proper test isolation or "
-            "set DisallowedDatabaseQueriesTests.allow_database_queries to True to silence this failure."
+            "Database queries are not allowed in SimpleTestCase subclasses. "
+            "Either subclass TestCase or TransactionTestCase to ensure proper "
+            "test isolation or add 'default' to "
+            "test_utils.tests.DisallowedDatabaseQueriesTests.databases to "
+            "silence this failure."
         )
         with self.assertRaisesMessage(AssertionError, expected_message):
             Car.objects.first()
 
-
-class DisallowedDatabaseQueriesChunkedCursorsTests(SimpleTestCase):
-    def test_disallowed_database_queries(self):
+    def test_disallowed_database_chunked_cursor_queries(self):
         expected_message = (
-            "Database queries aren't allowed in SimpleTestCase. Either use "
-            "TestCase or TransactionTestCase to ensure proper test isolation or "
-            "set DisallowedDatabaseQueriesChunkedCursorsTests.allow_database_queries "
-            "to True to silence this failure."
+            "Database queries are not allowed in SimpleTestCase subclasses. "
+            "Either subclass TestCase or TransactionTestCase to ensure proper "
+            "test isolation or add 'default' to "
+            "test_utils.tests.DisallowedDatabaseQueriesTests.databases to "
+            "silence this failure."
         )
         with self.assertRaisesMessage(AssertionError, expected_message):
             next(Car.objects.iterator())
 
 
 class AllowedDatabaseQueriesTests(SimpleTestCase):
-    allow_database_queries = True
+    databases = {'default'}
 
     def test_allowed_database_queries(self):
         Car.objects.first()
 
+    def test_allowed_database_chunked_cursor_queries(self):
+        next(Car.objects.iterator(), None)
+
+
+class DatabaseAliasTests(SimpleTestCase):
+    def setUp(self):
+        self.addCleanup(setattr, self.__class__, 'databases', self.databases)
+
+    def test_no_close_match(self):
+        self.__class__.databases = {'void'}
+        message = (
+            "test_utils.tests.DatabaseAliasTests.databases refers to 'void' which is not defined "
+            "in settings.DATABASES."
+        )
+        with self.assertRaisesMessage(ImproperlyConfigured, message):
+            self._validate_databases()
+
+    def test_close_match(self):
+        self.__class__.databases = {'defualt'}
+        message = (
+            "test_utils.tests.DatabaseAliasTests.databases refers to 'defualt' which is not defined "
+            "in settings.DATABASES. Did you mean 'default'?"
+        )
+        with self.assertRaisesMessage(ImproperlyConfigured, message):
+            self._validate_databases()
+
+    def test_match(self):
+        self.__class__.databases = {'default', 'other'}
+        self.assertEqual(self._validate_databases(), frozenset({'default', 'other'}))
+
+    def test_all(self):
+        self.__class__.databases = '__all__'
+        self.assertEqual(self._validate_databases(), frozenset(connections))
+
 
 @isolate_apps('test_utils', attr_name='class_apps')
 class IsolatedAppsTests(SimpleTestCase):