Support async tests decorated with override_config

constance/test/unittest.py

@@ -1,5 +1,7 @@
 from functools import wraps
 
+from asgiref.sync import iscoroutinefunction
+from asgiref.sync import sync_to_async
 from django import VERSION as DJANGO_VERSION
 from django.test import SimpleTestCase
 from django.test.utils import override_settings
@@ -27,10 +29,22 @@ def __call__(self, test_func):
                 raise Exception("Only subclasses of Django SimpleTestCase can be decorated with override_config")
             return self.modify_test_case(test_func)
 
-        @wraps(test_func)
-        def inner(*args, **kwargs):
-            with self:
-                return test_func(*args, **kwargs)
+        if iscoroutinefunction(test_func):
+
+            @wraps(test_func)
+            async def inner(*args, **kwargs):
+                try:
+                    await sync_to_async(self.enable, thread_sensitive=True)()
+                    return await test_func(*args, **kwargs)
+                finally:
+                    await sync_to_async(self.disable, thread_sensitive=True)()
+
+        else:
+
+            @wraps(test_func)
+            def inner(*args, **kwargs):
+                with self:
+                    return test_func(*args, **kwargs)
 
         return inner
 

docs/testing.rst

@@ -40,6 +40,11 @@ method level and also as a
                 self.assertEqual(config.YOUR_FAVOURITE_COLOR, "Blue?")
 
 
+The method decorator also supports ``async def`` tests. The overridden values
+remain active until the awaited test completes, including when it raises an
+exception.
+
+
 Pytest usage
 ~~~~~~~~~~~~
 

tests/test_test_overrides.py

@@ -1,4 +1,10 @@
+import asyncio
+from unittest.mock import patch
+
+from asgiref.sync import async_to_sync
+from asgiref.sync import iscoroutinefunction
 from django.test import TestCase
+from django.test import TransactionTestCase
 
 from constance import config
 from constance.test import override_config
@@ -35,3 +41,51 @@ class OverrideConfigClassDecoratorTestCase(TestCase):
     def test_override_config_on_class_changes_config_value(self):
         """Assert that the class decorator changes config.BOOL_VALUE."""
         self.assertFalse(config.BOOL_VALUE)
+
+
+class OverrideConfigAsyncDecoratorTestCase(TransactionTestCase):
+    @override_config(BOOL_VALUE=False)
+    async def test_override_config_on_async_method(self):
+        self.assertFalse(await config.BOOL_VALUE)
+        await asyncio.sleep(0)
+        self.assertFalse(await config.BOOL_VALUE)
+
+    def test_async_override_lasts_until_await_completes(self):
+        @override_config(BOOL_VALUE=False)
+        async def decorated():
+            self.assertFalse(await config.BOOL_VALUE)
+            await asyncio.sleep(0)
+            self.assertFalse(await config.BOOL_VALUE)
+            return "completed"
+
+        self.assertTrue(iscoroutinefunction(decorated))
+        self.assertEqual(async_to_sync(decorated)(), "completed")
+        self.assertTrue(config.BOOL_VALUE)
+
+    def test_async_override_restores_after_exception(self):
+        @override_config(BOOL_VALUE=False)
+        async def decorated():
+            self.assertFalse(await config.BOOL_VALUE)
+            await asyncio.sleep(0)
+            raise ValueError("test failure")
+
+        with self.assertRaisesMessage(ValueError, "test failure"):
+            async_to_sync(decorated)()
+        self.assertTrue(config.BOOL_VALUE)
+
+    def test_async_override_with_database_backend(self):
+        from constance import settings
+        from constance.base import Config
+
+        with patch.object(settings, "BACKEND", "constance.backends.database.DatabaseBackend"):
+            database_config = Config()
+        with patch("constance.test.unittest.config", database_config):
+
+            @override_config(BOOL_VALUE=False)
+            async def decorated():
+                self.assertFalse(await database_config.BOOL_VALUE)
+                await asyncio.sleep(0)
+                self.assertFalse(await database_config.BOOL_VALUE)
+
+            async_to_sync(decorated)()
+        self.assertTrue(database_config.BOOL_VALUE)