From c9610eca9907ef50a06a34e9b9b59414a274d216 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jind=C5=99ich=20B=C3=A4r?= <jindrichbar@gmail.com>
Date: Thu, 16 May 2024 13:47:22 +0200
Subject: [PATCH] feat: throw ProxyError with `cause`

---
 src/hooks/proxy.ts      | 4 +++-
 src/resolve-protocol.ts | 6 +++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/hooks/proxy.ts b/src/hooks/proxy.ts
index e16f98a..3ca15bd 100644
--- a/src/hooks/proxy.ts
+++ b/src/hooks/proxy.ts
@@ -24,11 +24,13 @@ export async function proxyHook(options: Options): Promise<void> {
     }
 }
 
+export class ProxyError extends Error {}
+
 function validateProxyProtocol(protocol: string) {
     const isSupported = protocol === 'http:' || protocol === 'https:';
 
     if (!isSupported) {
-        throw new Error(`Proxy URL protocol "${protocol}" is not supported. Please use HTTP or HTTPS.`);
+        throw new ProxyError(`Proxy URL protocol "${protocol}" is not supported. Please use HTTP or HTTPS.`);
     }
 }
 
diff --git a/src/resolve-protocol.ts b/src/resolve-protocol.ts
index 8410ab2..c6c5bab 100644
--- a/src/resolve-protocol.ts
+++ b/src/resolve-protocol.ts
@@ -4,6 +4,7 @@ import { URL } from 'node:url';
 import { type Headers } from 'got';
 import { auto, type ResolveProtocolConnectFunction, type ResolveProtocolFunction } from 'http2-wrapper';
 import QuickLRU from 'quick-lru';
+import { ProxyError } from './hooks/proxy.js';
 
 const connect = async (proxyUrl: string, options: tls.ConnectionOptions, callback: () => void) => new Promise<TLSSocket>((resolve, reject) => {
     let host = `${options.host}:${options.port}`;
@@ -42,11 +43,10 @@ const connect = async (proxyUrl: string, options: tls.ConnectionOptions, callbac
 
             request.once('connect', (response, socket, head) => {
                 if (response.statusCode !== 200 || head.length > 0) {
-                    reject(new Error(`Proxy responded with ${response.statusCode} ${response.statusMessage}: ${head.length} bytes.
+                    reject(new ProxyError(`Proxy responded with ${response.statusCode} ${response.statusMessage}: ${head.length} bytes.
 
 Below is the first 100 bytes of the proxy response body:
-${head.toString('utf8', 0, 100)}
-`));
+${head.toString('utf8', 0, 100)}`, { cause: head.toString('utf8') }));
                     socket.destroy();
                     return;
                 }