refactor(#1136): replace http-proxy w/ httpxy

cspell.json

@@ -52,6 +52,7 @@
     "typicode",
     "vhosted",
     "websockets",
-    "xfwd"
+    "xfwd",
+    "httpxy"
   ]
 }

package.json

@@ -89,9 +89,8 @@
     "ws": "8.19.0"
   },
   "dependencies": {
-    "@types/http-proxy": "^1.17.15",
     "debug": "^4.3.6",
-    "http-proxy": "^1.18.1",
+    "httpxy": "^0.2.2",
     "is-glob": "^4.0.3",
     "is-plain-object": "^5.0.0",
     "micromatch": "^4.0.8"

src/handlers/response-interceptor.ts

@@ -8,7 +8,7 @@ const debug = Debug.extend('response-interceptor');
 
 type Interceptor<TReq = http.IncomingMessage, TRes = http.ServerResponse> = (
   buffer: Buffer,
-  proxyRes: TReq,
+  proxyRes: http.IncomingMessage,
   req: TReq,
   res: TRes,
 ) => Promise<Buffer | string>;
@@ -25,7 +25,7 @@ export function responseInterceptor<
   TRes extends http.ServerResponse = http.ServerResponse,
 >(interceptor: Interceptor<TReq, TRes>) {
   return async function proxyResResponseInterceptor(
-    proxyRes: TReq,
+    proxyRes: http.IncomingMessage,
     req: TReq,
     res: TRes,
   ): Promise<void> {
@@ -34,7 +34,7 @@ export function responseInterceptor<
     let buffer = Buffer.from('', 'utf8');
 
     // decompress proxy response
-    const _proxyRes = decompress<TReq>(proxyRes, proxyRes.headers['content-encoding']);
+    const _proxyRes = decompress(proxyRes, proxyRes.headers['content-encoding']);
 
     // concat data stream
     _proxyRes.on('data', (chunk) => (buffer = Buffer.concat([buffer, chunk])));

src/http-proxy-middleware.ts

@@ -2,7 +2,7 @@ import type * as http from 'node:http';
 import type * as https from 'node:https';
 import type * as net from 'node:net';
 
-import * as httpProxy from 'http-proxy';
+import { type ProxyServer, createProxyServer } from 'httpxy';
 
 import { verifyConfig } from './configuration';
 import { Debug as debug } from './debug';
@@ -18,7 +18,7 @@ export class HttpProxyMiddleware<TReq, TRes> {
   private wsInternalSubscribed = false;
   private serverOnCloseSubscribed = false;
   private proxyOptions: Options<TReq, TRes>;
-  private proxy: httpProxy<TReq, TRes>;
+  private proxy: ProxyServer<TReq, TRes>;
   private pathRewriter;
   private logger: Logger;
 
@@ -28,7 +28,7 @@ export class HttpProxyMiddleware<TReq, TRes> {
     this.logger = getLogger(options as unknown as Options);
 
     debug(`create proxy server`);
-    this.proxy = httpProxy.createProxyServer({});
+    this.proxy = createProxyServer({});
 
     this.registerPlugins(this.proxy, this.proxyOptions);
 
@@ -46,11 +46,41 @@ export class HttpProxyMiddleware<TReq, TRes> {
   // https://github.com/Microsoft/TypeScript/wiki/'this'-in-TypeScript#red-flags-for-this
   public middleware: RequestHandler = (async (req, res, next?) => {
     if (this.shouldProxy(this.proxyOptions.pathFilter, req)) {
+      let activeProxyOptions: Options<TReq, TRes>;
       try {
-        const activeProxyOptions = await this.prepareProxyRequest(req);
+        // Preparation Phase: Apply router and path rewriter.
+        activeProxyOptions = await this.prepareProxyRequest(req);
+
+        // [Smoking Gun] httpxy is inconsistent with error handling:
+        // 1. If target is missing (here), it emits 'error' but returns a boolean (bypassing our catch/next).
+        // 2. If a network error occurs (in proxy.web), it rejects the promise but SKIPS emitting 'error'.
+        // We manually throw here to force Case 1 into the catch block so next(err) is called for Express.
+        if (!activeProxyOptions.target && !activeProxyOptions.forward) {
+          throw new Error('Must provide a proper URL as target');
+        }
+      } catch (err) {
+        next?.(err);
+        return;
+      }
+
+      try {
+        // Proxying Phase: Handle the actual web request.
         debug(`proxy request to target: %O`, activeProxyOptions.target);
-        this.proxy.web(req, res, activeProxyOptions);
+        await this.proxy.web(req, res, activeProxyOptions);
       } catch (err) {
+        // Manually emit 'error' event because httpxy's promise-based API does not emit it automatically.
+        // This is crucial for backward compatibility with HPM plugins (like error-response-plugin)
+        // and custom listeners registered via the 'on: { error: ... }' option.
+
+        /**
+         * TODO: Ideally, TReq and TRes should be restricted via "TReq extends http.IncomingMessage = http.IncomingMessage"
+         * and "TRes extends http.ServerResponse = http.ServerResponse", which allows us to avoid the "req as TReq" below.
+         *
+         * However, making TReq and TRes constrained types may cause a breaking change for TypeScript users downstream.
+         * So we leave this as a TODO for now, and revisit it in a future major release.
+         */
+        this.proxy.emit('error', err as Error, req as TReq, res, activeProxyOptions.target);
+
         next?.(err);
       }
     } else {
@@ -70,7 +100,9 @@ export class HttpProxyMiddleware<TReq, TRes> {
     if (server && !this.serverOnCloseSubscribed) {
       server.on('close', () => {
         debug('server close signal received: closing proxy server');
-        this.proxy.close();
+        this.proxy.close(() => {
+          debug('proxy server closed');
+        });
       });
       this.serverOnCloseSubscribed = true;
     }
@@ -81,7 +113,7 @@ export class HttpProxyMiddleware<TReq, TRes> {
     }
   }) as RequestHandler;
 
-  private registerPlugins(proxy: httpProxy<TReq, TRes>, options: Options<TReq, TRes>) {
+  private registerPlugins(proxy: ProxyServer<TReq, TRes>, options: Options<TReq, TRes>) {
     const plugins = getPlugins<TReq, TRes>(options);
     plugins.forEach((plugin) => {
       debug(`register plugin: "${getFunctionName(plugin)}"`);
@@ -103,13 +135,21 @@ export class HttpProxyMiddleware<TReq, TRes> {
     try {
       if (this.shouldProxy(this.proxyOptions.pathFilter, req)) {
         const activeProxyOptions = await this.prepareProxyRequest(req);
-        this.proxy.ws(req, socket, head, activeProxyOptions);
+        await this.proxy.ws(req, socket, activeProxyOptions, head);
         debug('server upgrade event received. Proxying WebSocket');
       }
     } catch (err) {
       // This error does not include the URL as the fourth argument as we won't
       // have the URL if `this.prepareProxyRequest` throws an error.
-      this.proxy.emit('error', err, req, socket);
+
+      /**
+       * TODO: Ideally, TReq and TRes should be restricted via "TReq extends http.IncomingMessage = http.IncomingMessage"
+       * and "TRes extends http.ServerResponse = http.ServerResponse", which allows us to avoid the "req as TReq" below.
+       *
+       * However, making TReq and TRes constrained types may cause a breaking change for TypeScript users downstream.
+       * So we leave this as a TODO for now, and revisit it in a future major release.
+       */
+      this.proxy.emit('error', err as Error, req as TReq, socket);
     }
   };
 

src/plugins/default/error-response-plugin.ts

@@ -16,7 +16,7 @@ function isSocketLike(obj: any): obj is Socket {
 export const errorResponsePlugin: Plugin = (proxyServer, options) => {
   proxyServer.on('error', (err, req, res, target?) => {
     // Re-throw error. Not recoverable since req & res are empty.
-    if (!req && !res) {
+    if (!req || !res) {
       throw err; // "Error: Must provide a proper URL as target"
     }
 

src/plugins/default/proxy-events.ts

@@ -25,8 +25,21 @@ const debug = Debug.extend('proxy-events-plugin');
  * ```
  */
 export const proxyEventsPlugin: Plugin = (proxyServer, options) => {
-  Object.entries(options.on || {}).forEach(([eventName, handler]) => {
-    debug(`register event handler: "${eventName}" -> "${getFunctionName(handler)}"`);
-    proxyServer.on(eventName, handler as (...args: unknown[]) => void);
-  });
+  if (!options.on) {
+    return;
+  }
+
+  // hoist variable here for better typing
+  let eventName: keyof typeof options.on;
+  // for in provide better typing than Object.entries()
+  for (eventName in options.on) {
+    if (Object.prototype.hasOwnProperty.call(options.on, eventName)) {
+      const handler = options.on[eventName];
+      if (!handler) {
+        continue;
+      }
+      debug(`register event handler: "${eventName}" -> "${getFunctionName(handler)}"`);
+      proxyServer.on<keyof typeof options.on>(eventName, handler as (...args: unknown[]) => void);
+    }
+  }
 };

src/types.ts

@@ -5,7 +5,7 @@
 import type * as http from 'node:http';
 import type * as net from 'node:net';
 
-import type * as httpProxy from 'http-proxy';
+import type { ProxyServer, ProxyServerOptions } from 'httpxy';
 
 export type NextFunction<T = (err?: any) => void> = T;
 
@@ -24,25 +24,38 @@ export type Filter<TReq = http.IncomingMessage> =
   | ((pathname: string, req: TReq) => boolean);
 
 export interface Plugin<TReq = http.IncomingMessage, TRes = http.ServerResponse> {
-  (proxyServer: httpProxy<TReq, TRes>, options: Options<TReq, TRes>): void;
+  (proxyServer: ProxyServer<TReq, TRes>, options: Options<TReq, TRes>): void;
 }
 
 export interface OnProxyEvent<TReq = http.IncomingMessage, TRes = http.ServerResponse> {
-  error?: httpProxy.ErrorCallback<Error, TReq, TRes>;
-  proxyReq?: httpProxy.ProxyReqCallback<http.ClientRequest, TReq, TRes>;
-  proxyReqWs?: httpProxy.ProxyReqWsCallback<http.ClientRequest, TReq>;
-  proxyRes?: httpProxy.ProxyResCallback<TReq, TRes>;
-  open?: httpProxy.OpenCallback;
-  close?: httpProxy.CloseCallback<TReq>;
-  start?: httpProxy.StartCallback<TReq, TRes>;
-  end?: httpProxy.EndCallback<TReq, TRes>;
-  econnreset?: httpProxy.EconnresetCallback<Error, TReq, TRes>;
+  error?: (err: Error, req: TReq, res: TRes | net.Socket, target?: string | Partial<URL>) => void;
+  proxyReq?: (
+    proxyReq: http.ClientRequest,
+    req: TReq,
+    res: TRes,
+    options: ProxyServerOptions,
+  ) => void;
+  proxyReqWs?: (
+    proxyReq: http.ClientRequest,
+    req: TReq,
+    socket: net.Socket,
+    options: ProxyServerOptions,
+    head: any,
+  ) => void;
+  proxyRes?: (proxyRes: TReq, req: TReq, res: TRes) => void;
+  open?: (proxySocket: net.Socket) => void;
+  close?: (proxyRes: TReq, proxySocket: net.Socket, proxyHead: any) => void;
+  start?: (req: TReq, res: TRes, target: string | Partial<URL>) => void;
+  end?: (req: TReq, res: TRes, proxyRes: TReq) => void;
+  econnreset?: (err: Error, req: TReq, res: TRes, target: string | Partial<URL>) => void;
 }
 
 export type Logger = Pick<Console, 'info' | 'warn' | 'error'>;
 
-export interface Options<TReq = http.IncomingMessage, TRes = http.ServerResponse>
-  extends httpProxy.ServerOptions {
+export interface Options<
+  TReq = http.IncomingMessage,
+  TRes = http.ServerResponse,
+> extends ProxyServerOptions {
   /**
    * Narrow down requests to proxy or not.
    * Filter on {@link http.IncomingMessage.url `pathname`} which is relative to the proxy's "mounting" point in the server.
@@ -122,9 +135,9 @@ export interface Options<TReq = http.IncomingMessage, TRes = http.ServerResponse
    * @link https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/router.md
    */
   router?:
-    | { [hostOrPath: string]: httpProxy.ServerOptions['target'] }
-    | ((req: TReq) => httpProxy.ServerOptions['target'])
-    | ((req: TReq) => Promise<httpProxy.ServerOptions['target']>);
+    | { [hostOrPath: string]: ProxyServerOptions['target'] }
+    | ((req: TReq) => ProxyServerOptions['target'])
+    | ((req: TReq) => Promise<ProxyServerOptions['target']>);
   /**
    * Log information from http-proxy-middleware
    * @example

tsconfig.json

@@ -9,7 +9,8 @@
     "incremental": true,
     "declaration": true,
     "strict": true,
-    "noImplicitAny": false
+    "noImplicitAny": false,
+    "skipLibCheck": true
   },
   "include": ["./src"]
 }

yarn.lock

@@ -1508,13 +1508,6 @@
   resolved "https://registry.yarnpkg.com/@types/http-errors/-/http-errors-2.0.1.tgz#20172f9578b225f6c7da63446f56d4ce108d5a65"
   integrity sha512-/K3ds8TRAfBvi5vfjuz8y6+GiAYBZ0x4tXv1Av6CWBWn0IlADc+ZX9pMq7oU0fNQPnBwIZl3rmeLp6SBApbxSQ==
 
-"@types/http-proxy@^1.17.15":
-  version "1.17.15"
-  resolved "https://registry.yarnpkg.com/@types/http-proxy/-/http-proxy-1.17.15.tgz#12118141ce9775a6499ecb4c01d02f90fc839d36"
-  integrity sha512-25g5atgiVNTIv0LBDTg1H74Hvayx0ajtJPLLcYE3whFv75J0pWNtOBzaXJQgDTmrX1bx5U9YC2w/n65BN1HwRQ==
-  dependencies:
-    "@types/node" "*"
-
 "@types/is-glob@4.0.4":
   version "4.0.4"
   resolved "https://registry.yarnpkg.com/@types/is-glob/-/is-glob-4.0.4.tgz#1d60fa47ff70abc97b4d9ea45328747c488b3a50"
@@ -2891,11 +2884,6 @@ eventemitter3@^3.1.0:
   resolved "https://registry.yarnpkg.com/eventemitter3/-/eventemitter3-3.1.2.tgz#2d3d48f9c346698fce83a85d7d664e98535df6e7"
   integrity sha512-tvtQIeLVHjDkJYnzf2dgVMxfuSGJeM/7UCG17TT4EumTfNtF+0nebF/4zWOIkCreAbtNqhGEboB6BWrwqNaw4Q==
 
-eventemitter3@^4.0.0:
-  version "4.0.7"
-  resolved "https://registry.yarnpkg.com/eventemitter3/-/eventemitter3-4.0.7.tgz#2de9b68f6528d5644ef5c59526a1b4a07306169f"
-  integrity sha512-8guHBZCwKnFhYdHr2ysuRWErTwhoN2X8XELRlrRwpmfeY2jjuUN4taQMsULKUVo1K4DvZl+0pgfyoysHxvmvEw==
-
 eventemitter3@^5.0.1:
   version "5.0.1"
   resolved "https://registry.yarnpkg.com/eventemitter3/-/eventemitter3-5.0.1.tgz#53f5ffd0a492ac800721bb42c66b841de96423c4"
@@ -3139,11 +3127,6 @@ flatted@^3.2.9:
   resolved "https://registry.yarnpkg.com/flatted/-/flatted-3.4.2.tgz#f5c23c107f0f37de8dbdf24f13722b3b98d52726"
   integrity sha512-PjDse7RzhcPkIJwy5t7KPWQSZ9cAbzQXcafsetQoD7sOJRQlGikNbx7yZp2OotDnJyrDcbyRq3Ttb18iYOqkxA==
 
-follow-redirects@^1.0.0:
-  version "1.15.6"
-  resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.15.6.tgz#7f815c0cda4249c74ff09e95ef97c23b5fd0399b"
-  integrity sha512-wWN62YITEaOpSK584EZXJafH1AGpO8RVgElfkuXbTOrPX4fIfOyEpW/CsiNd8JdYrAoOvafRTOEnvsO++qCqFA==
-
 foreground-child@^3.1.0:
   version "3.3.1"
   resolved "https://registry.yarnpkg.com/foreground-child/-/foreground-child-3.3.1.tgz#32e8e9ed1b68a3497befb9ac2b6adf92a638576f"
@@ -3459,15 +3442,6 @@ http-proxy-agent@^7.0.0:
     agent-base "^7.1.0"
     debug "^4.3.4"
 
-http-proxy@^1.18.1:
-  version "1.18.1"
-  resolved "https://registry.yarnpkg.com/http-proxy/-/http-proxy-1.18.1.tgz#401541f0534884bbf95260334e72f88ee3976549"
-  integrity sha512-7mz/721AbnJwIVbnaSv1Cz3Am0ZLT/UBwkC92VlxhXv/k/BBQfM2fXElQNC27BVGr0uwUpplYPQM9LnaBMR5NQ==
-  dependencies:
-    eventemitter3 "^4.0.0"
-    follow-redirects "^1.0.0"
-    requires-port "^1.0.0"
-
 http2-wrapper@^2.2.1:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/http2-wrapper/-/http2-wrapper-2.2.1.tgz#310968153dcdedb160d8b72114363ef5fce1f64a"
@@ -3492,6 +3466,11 @@ https-proxy-agent@^7.0.6:
     agent-base "^7.1.2"
     debug "4"
 
+httpxy@^0.2.2:
+  version "0.2.2"
+  resolved "https://registry.yarnpkg.com/httpxy/-/httpxy-0.2.2.tgz#1603165cfd12087f2039c4a8532ce61eab5d84e5"
+  integrity sha512-QnS6mAOqvdmfctFaD/Kp5cwRMcaUhEmIyw2rjVYnhJb8EuAyd/79biT/50HUTKvq/PwoXYTP6J3d9TUxzHFZwA==
+
 human-signals@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/human-signals/-/human-signals-2.1.0.tgz#dc91fcba42e4d06e4abaed33b3e7a3c02f514ea0"
@@ -5102,11 +5081,6 @@ require-from-string@^2.0.2:
   resolved "https://registry.yarnpkg.com/require-from-string/-/require-from-string-2.0.2.tgz#89a7fdd938261267318eafe14f9c32e598c36909"
   integrity sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==
 
-requires-port@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/requires-port/-/requires-port-1.0.0.tgz#925d2601d39ac485e091cf0da5c6e694dc3dcaff"
-  integrity sha512-KigOCHcocU3XODJxsu8i/j8T9tzT4adHiecwORRQ0ZZFcp7ahwXuRU1m+yuO90C5ZUyGeGfocHDI14M3L3yDAQ==
-
 resolve-alpn@^1.2.0:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/resolve-alpn/-/resolve-alpn-1.2.1.tgz#b7adbdac3546aaaec20b45e7d8265927072726f9"