add types for events

Author: sapphi-red

lib/http-proxy/index.ts

@@ -93,7 +93,51 @@ export type ErrorCallback =
     target?: ProxyTargetUrl,
   ) => void;
 
-export class ProxyServer extends EventEmitter {
+type ProxyServerEventMap = {
+  error: Parameters<ErrorCallback>;
+  start: [
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+    target: ProxyTargetUrl,
+  ];
+  open: [socket: net.Socket];
+  proxyReq: [
+    proxyReq: http.ClientRequest,
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+    options: ServerOptions,
+  ];
+  proxyRes: [
+    proxyRes: http.IncomingMessage,
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+  ];
+  proxyReqWs: [
+    proxyReq: http.ClientRequest,
+    req: http.IncomingMessage,
+    socket: net.Socket,
+    options: ServerOptions,
+    head: any,
+  ];
+  econnreset: [
+    err: Error,
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+    target: ProxyTargetUrl,
+  ];
+  end: [
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+    proxyRes: http.IncomingMessage,
+  ];
+  close: [
+    proxyRes: http.IncomingMessage,
+    proxySocket: net.Socket,
+    proxyHead: any,
+  ];
+}
+
+export class ProxyServer extends EventEmitter<ProxyServerEventMap> {
   /**
    * Used for proxying WS(S) requests
    * @param req - Client request.
@@ -206,8 +250,8 @@ export class ProxyServer extends EventEmitter {
           // and there's no way for a user of http-proxy-3 to get ahold
           // of this res object and attach their own error handler until
           // after the passes. So we better attach one ASAP right here:
-          res.on("error", (...args) => {
-            this.emit("error", ...args);
+          (res as net.Socket).on("error", (err) => {
+            this.emit("error", err, req, res);
           });
         }
         let counter = args.length - 1;
@@ -240,7 +284,7 @@ export class ProxyServer extends EventEmitter {
         }
 
         if (!requestOptions.target && !requestOptions.forward) {
-          this.emit("error", new Error("Must set target or forward"));
+          this.emit("error", new Error("Must set target or forward"), req, res);
           return;
         }
 

lib/test/http/custom-proxy-error.test.ts

@@ -1,10 +1,11 @@
 /*
   custom-proxy-error.test.ts: Example of using the custom `proxyError` event.
-  
+
 pnpm test ./custom-proxy-error.test.ts
 */
 
 import * as httpProxy from "../..";
+import * as http from "http";
 import getPort from "../get-port";
 import fetch from "node-fetch";
 
@@ -27,7 +28,7 @@ describe("Test proxying over HTTP with latency", () => {
       .listen(ports.proxy);
 
     proxy.on("error", (_err, _req, res) => {
-      res.writeHead(500, {
+      (res as http.ServerResponse).writeHead(500, {
         "Content-Type": "text/plain",
       });
       res.end(CUSTOM_ERROR);

lib/test/lib/http-proxy-passes-web-incoming.test.ts

@@ -245,7 +245,7 @@ describe("#createProxyServer.web() using own http server", () => {
         proxyServer.close();
         expect(errReq).toEqual(req);
         expect(errRes).toEqual(res);
-        expect(err.code).toEqual("ECONNREFUSED");
+        expect((err as NodeJS.ErrnoException).code).toEqual("ECONNREFUSED");
         done();
       });
 
@@ -279,7 +279,7 @@ describe("#createProxyServer.web() using own http server", () => {
         proxyServer.close();
         expect(errReq).toEqual(req);
         expect(errRes).toEqual(res);
-        expect(err.code).toEqual("ECONNREFUSED");
+        expect((err as NodeJS.ErrnoException).code).toEqual("ECONNREFUSED");
         done();
       });
 
@@ -317,7 +317,7 @@ describe("#createProxyServer.web() using own http server", () => {
         expect(errReq).toEqual(req);
         expect(errRes).toEqual(res);
         expect(Date.now() - started).toBeGreaterThan(99);
-        expect(err.code).toEqual("ECONNRESET");
+        expect((err as NodeJS.ErrnoException).code).toEqual("ECONNRESET");
         done();
       });
 
@@ -362,7 +362,7 @@ describe("#createProxyServer.web() using own http server", () => {
         server.close();
         expect(errReq).toEqual(req);
         expect(errRes).toEqual(res);
-        expect(err.code).toEqual("ECONNRESET");
+        expect((err as NodeJS.ErrnoException).code).toEqual("ECONNRESET");
         doneOne();
       });
 

lib/test/lib/http-proxy.test.ts

@@ -168,7 +168,7 @@ describe("#createProxyServer() method with error response", () => {
 
     proxy
       .on("error", (err) => {
-        expect(err.code).toEqual("ECONNREFUSED");
+        expect((err as NodeJS.ErrnoException).code).toEqual("ECONNREFUSED");
         proxy.close();
         done();
       })
@@ -198,7 +198,7 @@ describe("#createProxyServer setting the correct timeout value", () => {
       .listen(ports.proxy);
 
     proxy.on("error", (e) => {
-      expect(e.code).toEqual("ECONNRESET");
+      expect((e as NodeJS.ErrnoException).code).toEqual("ECONNRESET");
     });
 
     const source = http.createServer((_req, res) => {
@@ -327,7 +327,7 @@ describe("#createProxyServer using the ws-incoming passes", () => {
     });
 
     proxy.on("error", (err) => {
-      expect(err.code).toEqual("ECONNREFUSED");
+      expect((err as NodeJS.ErrnoException).code).toEqual("ECONNREFUSED");
       proxyServer.close();
       maybe_done();
     });

lib/test/middleware/body-decoder-middleware.test.ts

@@ -34,7 +34,8 @@ describe("connect.bodyParser() middleware in http-proxy-3", () => {
     });
 
     // re-serialize parsed body before proxying.
-    proxy.on("proxyReq", (proxyReq, req, _res, _options) => {
+    proxy.on("proxyReq", (proxyReq, rawReq, _res, _options) => {
+      const req = rawReq as http.IncomingMessage & { body?: any };
       if (!req.body || !Object.keys(req.body).length) {
         return;
       }