We need HttpResponse::hasResponded

src/HttpContext.h

@@ -70,6 +70,14 @@ private:
             /* Init socket ext */
             new (static_dispatch(us_ssl_socket_ext, us_socket_ext)(s)) HttpResponseData<SSL>;
 
+            /* Call filter */
+            HttpContextData<SSL> *httpContextData = getSocketContextDataS(s);
+            for (auto &f : httpContextData->filterHandlers) {
+                f((HttpResponse<SSL> *) s, 1);
+            }
+
+            // todo: handle filter closing the socket?
+
             return s;
         });
 
@@ -78,6 +86,12 @@ private:
             /* Get socket ext */
             HttpResponseData<SSL> *httpResponseData = (HttpResponseData<SSL> *) static_dispatch(us_ssl_socket_ext, us_socket_ext)(s);
 
+            /* Call filter */
+            HttpContextData<SSL> *httpContextData = getSocketContextDataS(s);
+            for (auto &f : httpContextData->filterHandlers) {
+                f((HttpResponse<SSL> *) s, -1);
+            }
+
             /* Signal broken HTTP request only if we have a pending request */
             if (httpResponseData->onAborted) {
                 httpResponseData->onAborted();
@@ -145,6 +159,13 @@ private:
                     return nullptr;
                 }
 
+                /* Returning from a request handler without responding or attaching an onAborted handler is ill-use */
+                if (!((HttpResponse<SSL> *) s)->hasResponded() && !httpResponseData->onAborted) {
+                    /* Throw exception here? */
+                    std::cerr << "µWebSockets ill-use: Returning from a request handler without responding or attaching an abort handler is forbidden." << std::endl;
+                    std::terminate();
+                }
+
                 /* Continue parsing */
                 return s;
 
@@ -269,6 +290,10 @@ public:
         static_dispatch(us_ssl_socket_context_free, us_socket_context_free)(getSocketContext());
     }
 
+    void filter(fu2::unique_function<void(HttpResponse<SSL> *, int)> &&filterHandler) {
+        getSocketContextData()->filterHandlers.emplace_back(std::move(filterHandler));
+    }
+
     /* Register an HTTP route handler acording to URL pattern */
     void onHttp(std::string method, std::string pattern, std::function<void(uWS::HttpResponse<SSL> *, uWS::HttpRequest *)> handler) {
         HttpContextData<SSL> *httpContextData = getSocketContextData();