From f034f6ae16e71e0d65779578d8ed66f3be6db03b Mon Sep 17 00:00:00 2001
From: Roberto Prevato <roberto.prevato@gmail.com>
Date: Wed, 17 Jan 2024 20:49:48 +0100
Subject: [PATCH] Fix #470

---
 CHANGELOG.md                     |  4 +++-
 blacksheep/server/application.py |  3 ++-
 blacksheep/server/routing.py     | 33 +++++++++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f493268..2e54c89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [2.0.6] - 2024-01-16 :kr: :heart:
+## [2.0.6] - 2024-01-17 :kr: :heart:
 
 - Adds built-in support for [Server-Sent events](https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events).
 - Adds a function to detect when the server process is terminating because it
@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Adds support for request handler normalization for methods defined as
   asynchronous generators. This feature is enabled by default only for
   ServerSentEvents, but can be configured for user defined types.
+- Raises exception when the default router is used to register routes, but not
+  associated to an application object. Fixes [#470](https://github.com/Neoteroi/BlackSheep/issues/470).
 
 Refer to the [BlackSheep documentation](https://www.neoteroi.dev/blacksheep/server-sent-events/)
 and to the [examples repository](https://github.com/Neoteroi/BlackSheep-Examples/tree/main/server-sent-events) for more information on server-sent events support.
diff --git a/blacksheep/server/application.py b/blacksheep/server/application.py
index 8ac2847..c52756c 100644
--- a/blacksheep/server/application.py
+++ b/blacksheep/server/application.py
@@ -64,7 +64,7 @@
     RoutesRegistry,
 )
 from blacksheep.server.routing import router as default_router
-from blacksheep.server.routing import validate_router
+from blacksheep.server.routing import validate_default_router, validate_router
 from blacksheep.server.websocket import WebSocket, format_reason
 from blacksheep.sessions import SessionMiddleware, SessionSerializer
 from blacksheep.settings.di import di_settings
@@ -706,6 +706,7 @@ async def start(self):
         if self.on_start:
             await self.on_start.fire()
 
+        validate_default_router()
         self.use_controllers()
         self.normalize_handlers()
         self.configure_middlewares()
diff --git a/blacksheep/server/routing.py b/blacksheep/server/routing.py
index aa3aa35..b6c0a72 100644
--- a/blacksheep/server/routing.py
+++ b/blacksheep/server/routing.py
@@ -66,6 +66,21 @@ class InvalidRouterConfigurationError(RouteException):
     """Base class for router configuration errors"""
 
 
+class OrphanDefaultRouterError(InvalidRouterConfigurationError):
+    """
+    Error raised when the default router was configured with routes, but it is not
+    associated to any application.
+    """
+
+    def __init__(self) -> None:
+        super().__init__(
+            "Invalid router configuration: the default router was used to register "
+            "routes, but it is not associated to any application object. To resolve, "
+            "ensure that the router bound to your application is used to register "
+            "routes. Do not use routing methods imported from the library."
+        )
+
+
 class SharedRouterError(InvalidRouterConfigurationError):
     """
     Error raised when the more than one application is using the same router.
@@ -941,13 +956,29 @@ def validate_router(app):
             # by uvicorn reload feature, when uvicorn is started programmatically.
             # See https://github.com/Neoteroi/BlackSheep/issues/438
             logging.getLogger("blacksheep.server").warning(
-                "[BlackSheep] The application was reloaded, resetting its router."
+                "The application was reloaded, resetting its router."
             )
             app_router.reset()
             return
         raise SharedRouterError()
 
 
+def validate_default_router():
+    """
+    This method ensures that the default router is associated to an application, if it
+    defines any route.
+    """
+    if set(router):
+        # The default router has routes defined, ensure that it is bound to an
+        # application
+        # verify that
+        try:
+            _apps_by_router_id[id(router)]
+        except KeyError:
+            # Not good
+            raise OrphanDefaultRouterError() from None
+
+
 # Singleton router used to store initial configuration,
 # before the application starts
 # this is used as *default* router, but it can be overridden;