Fixed tests, covered flags and events isolation modules

tests/test_utils/test_i18n.py

@@ -114,6 +114,24 @@ class TestSimpleI18nMiddleware:
         assert middleware not in dp.update.outer_middlewares
         assert middleware in dp.message.outer_middlewares
 
+    async def test_get_unknown_locale(self, i18n: I18n):
+        dp = Dispatcher()
+        middleware = SimpleI18nMiddleware(i18n=i18n)
+        middleware.setup(router=dp)
+
+        locale = await middleware.get_locale(
+            None,
+            {
+                "event_from_user": User(
+                    id=42,
+                    is_bot=False,
+                    first_name="Test",
+                    language_code="unknown",
+                )
+            },
+        )
+        assert locale == i18n.default_locale
+
 
 @pytest.mark.asyncio
 class TestConstI18nMiddleware: