Fixed #22811 -- Allowed setting both the old and new TEST database settings.

An ImproperlyConfigured exception will be raised they mismatch.

django/db/utils.py

@@ -183,6 +183,7 @@ class ConnectionHandler(object):
         'USER_CREATE': 'CREATE_USER',
         'PASSWD': 'PASSWORD',
     }
+    TEST_SETTING_RENAMES_REVERSE = {v: k for k, v in TEST_SETTING_RENAMES.items()}
 
     def prepare_test_settings(self, alias):
         """
@@ -193,18 +194,29 @@ class ConnectionHandler(object):
         except KeyError:
             raise ConnectionDoesNotExist("The connection %s doesn't exist" % alias)
 
+        test_dict_set = 'TEST' in conn
         test_settings = conn.setdefault('TEST', {})
+        old_test_settings = {}
         for key, value in six.iteritems(conn):
             if key.startswith('TEST_'):
                 new_key = key[5:]
                 new_key = self.TEST_SETTING_RENAMES.get(new_key, new_key)
-                if new_key in test_settings:
+                old_test_settings[new_key] = value
-                    raise ImproperlyConfigured("Connection %s has both %s and TEST[%s] specified." %
+
-                                               (alias, key, new_key))
+        if old_test_settings:
+            if test_dict_set:
+                if test_settings != old_test_settings:
+                    raise ImproperlyConfigured(
+                        "Connection '%s' has mismatched TEST and TEST_* "
+                        "database settings." % alias)
+            else:
+                test_settings = old_test_settings
+                for key, _ in six.iteritems(old_test_settings):
                     warnings.warn("In Django 1.9 the %s connection setting will be moved "
-                              "to a %s entry in the TEST setting" % (key, new_key),
+                                  "to a %s entry in the TEST setting" %
+                                  (self.TEST_SETTING_RENAMES_REVERSE.get(key, key), key),
                                   RemovedInDjango19Warning, stacklevel=2)
-                test_settings[new_key] = value
+
         for key in list(conn.keys()):
             if key.startswith('TEST_'):
                 del conn[key]

docs/ref/settings.txt

@@ -586,6 +586,8 @@ TEST
 
     All :setting:`TEST <DATABASE-TEST>` sub-entries used to be independent
     entries in the database settings dictionary, with a ``TEST_`` prefix.
+    For backwards compatibility with older versions of Django, you can define
+    both versions of the settings as long as they match.
     Further, ``TEST_CREATE``, ``TEST_USER_CREATE`` and ``TEST_PASSWD``
     were changed to ``CREATE_DB``, ``CREATE_USER`` and ``PASSWORD``
     respectively.

docs/releases/1.7.txt

@@ -1546,9 +1546,12 @@ will be removed in Django 1.8.
 
 Reorganization of database test settings
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 All database settings with a ``TEST_`` prefix have been deprecated in favor of
 entries in a :setting:`TEST <DATABASE-TEST>` dictionary in the database
-settings. The old settings will be supported until Django 1.9.
+settings. The old settings will be supported until Django 1.9. For backwards
+compatibility with older versions of Django, you can define both versions of
+the settings as long as they match.
 
 FastCGI support
 ~~~~~~~~~~~~~~~

tests/backends/tests.py

@@ -11,6 +11,7 @@ import unittest
 import warnings
 
 from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
 from django.core.management.color import no_style
 from django.db import (connection, connections, DEFAULT_DB_ALIAS,
     DatabaseError, IntegrityError, reset_queries, transaction)
@@ -1077,3 +1078,118 @@ class BackendUtilTests(TestCase):
               '0.1')
         equal('0.1234567890', 12, 0,
               '0')
+
+
+class DBTestSettingsRenamedTests(TestCase):
+
+    mismatch_msg = ("Connection 'test-deprecation' has mismatched TEST "
+                    "and TEST_* database settings.")
+
+    def setUp(self):
+        self.handler = ConnectionHandler()
+        self.db_settings = {'default': {}}
+
+    def test_mismatched_database_test_settings_1(self):
+        # if the TEST setting is used, all TEST_* keys must appear in it.
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {},
+                'TEST_NAME': 'foo',
+            }
+        })
+        with override_settings(DATABASES=self.db_settings):
+            with self.assertRaisesMessage(ImproperlyConfigured, self.mismatch_msg):
+                self.handler.prepare_test_settings('test-deprecation')
+
+    def test_mismatched_database_test_settings_2(self):
+        # if the TEST setting is used, all TEST_* keys must match.
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {'NAME': 'foo'},
+                'TEST_NAME': 'bar',
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            with self.assertRaisesMessage(ImproperlyConfigured, self.mismatch_msg):
+                self.handler.prepare_test_settings('test-deprecation')
+
+    def test_mismatched_database_test_settings_3(self):
+        # Verifies the mapping of an aliased key.
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {'CREATE_DB': 'foo'},
+                'TEST_CREATE': 'bar',
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            with self.assertRaisesMessage(ImproperlyConfigured, self.mismatch_msg):
+                self.handler.prepare_test_settings('test-deprecation')
+
+    def test_mismatched_database_test_settings_4(self):
+        # Verifies the mapping of an aliased key when the aliased key is missing.
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {},
+                'TEST_CREATE': 'bar',
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            with self.assertRaisesMessage(ImproperlyConfigured, self.mismatch_msg):
+                self.handler.prepare_test_settings('test-deprecation')
+
+    def test_mismatched_settings_old_none(self):
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {'CREATE_DB': None},
+                'TEST_CREATE': '',
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            with self.assertRaisesMessage(ImproperlyConfigured, self.mismatch_msg):
+                self.handler.prepare_test_settings('test-deprecation')
+
+    def test_mismatched_settings_new_none(self):
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {},
+                'TEST_CREATE': None,
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            with self.assertRaisesMessage(ImproperlyConfigured, self.mismatch_msg):
+                self.handler.prepare_test_settings('test-deprecation')
+
+    def test_matched_test_settings(self):
+        # should be able to define new settings and the old, if they match
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {'NAME': 'foo'},
+                'TEST_NAME': 'foo',
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            self.handler.prepare_test_settings('test-deprecation')
+
+    def test_new_settings_only(self):
+        # should be able to define new settings without the old
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST': {'NAME': 'foo'},
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            self.handler.prepare_test_settings('test-deprecation')
+
+    def test_old_settings_only(self):
+        # should be able to define old settings without the new
+        self.db_settings.update({
+            'test-deprecation': {
+                'TEST_NAME': 'foo',
+            },
+        })
+        with override_settings(DATABASES=self.db_settings):
+            self.handler.prepare_test_settings('test-deprecation')
+
+    def test_empty_settings(self):
+        with override_settings(DATABASES=self.db_settings):
+            self.handler.prepare_test_settings('default')