Add "res" event after "proxyRes", when the headers of res is already filled (using web-outgoing.js)

Author: dav1d8

index.d.ts

@@ -106,6 +106,7 @@ declare class Server extends events.EventEmitter {
     on(event: "proxyReq", listener: Server.ProxyReqCallback): this;
     on(event: "proxyRes", listener: Server.ProxyResCallback): this;
     on(event: "proxyReqWs", listener: Server.ProxyReqWsCallback): this;
+    on(event: "res", listener: Server.ResCallback): this;
     on(event: "econnreset", listener: Server.EconnresetCallback): this;
     on(event: "end", listener: Server.EndCallback): this;
     on(event: "open", listener: Server.OpenCallback): this;
@@ -117,6 +118,7 @@ declare class Server extends events.EventEmitter {
     once(event: "proxyReq", listener: Server.ProxyReqCallback): this;
     once(event: "proxyRes", listener: Server.ProxyResCallback): this;
     once(event: "proxyReqWs", listener: Server.ProxyReqWsCallback): this;
+    once(event: "res", listener: Server.ResCallback): this;
     once(event: "econnreset", listener: Server.EconnresetCallback): this;
     once(event: "end", listener: Server.EndCallback): this;
     once(event: "open", listener: Server.OpenCallback): this;
@@ -213,6 +215,11 @@ declare namespace Server {
         options: ServerOptions,
         head: any,
     ) => void;
+    type ResCallback<TIncomingMessage = http.IncomingMessage, TServerResponse = http.ServerResponse> = (
+        proxyRes: TIncomingMessage,
+        req: TIncomingMessage,
+        res: TServerResponse,
+    ) => void;
     type EconnresetCallback<TError = Error, TIncomingMessage = http.IncomingMessage, TServerResponse = http.ServerResponse> = (
         err: TError,
         req: TIncomingMessage,

lib/http-proxy/passes/web-incoming.js

@@ -191,6 +191,10 @@ module.exports = {
         }
       }
 
+      if (!options.selfHandleResponse) {
+        if(server) { server.emit('res', proxyRes, req, res); }
+      }
+
       if (!res.finished) {
         // Allow us to listen when the proxy has completed
         proxyRes.on('end', function () {