Add infrastructure for supporting multi-DB tests

Author: living180

tests/base.py

@@ -1,7 +1,7 @@
 import html5lib
 from asgiref.local import Local
 from django.http import HttpResponse
-from django.test import Client, RequestFactory, TestCase
+from django.test import Client, RequestFactory, TestCase, TransactionTestCase
 
 from debug_toolbar.toolbar import DebugToolbar
 
@@ -29,7 +29,7 @@ def handle_toolbar_created(sender, toolbar=None, **kwargs):
 rf = RequestFactory()
 
 
-class BaseTestCase(TestCase):
+class BaseMixin:
     client_class = ToolbarTestClient
 
     panel_id = None
@@ -67,6 +67,14 @@ def assertValidHTML(self, content):
             raise self.failureException("\n".join(msg_parts))
 
 
+class BaseTestCase(BaseMixin, TestCase):
+    pass
+
+
+class BaseMultiDBTestCase(BaseMixin, TransactionTestCase):
+    databases = {"default", "replica"}
+
+
 class IntegrationTestCase(TestCase):
     """Base TestCase for tests involving clients making requests."""
 

tests/settings.py

@@ -104,6 +104,20 @@
             "USER": "default_test",
         },
     },
+    "replica": {
+        "ENGINE": "django.{}db.backends.{}".format(
+            "contrib.gis." if USE_GIS else "", os.getenv("DB_BACKEND", "sqlite3")
+        ),
+        "NAME": os.getenv("DB_NAME", ":memory:"),
+        "USER": os.getenv("DB_USER"),
+        "PASSWORD": os.getenv("DB_PASSWORD"),
+        "HOST": os.getenv("DB_HOST", ""),
+        "PORT": os.getenv("DB_PORT", ""),
+        "TEST": {
+            "USER": "default_test",
+            "MIRROR": "default",
+        },
+    },
 }
 
 DEFAULT_AUTO_FIELD = "django.db.models.AutoField"