feat: log CONNECT error response body (#139)

Connected to apify/apify-proxy#823.

On an internal proxy error (such as trying to access an invalid or
unresolvable URL - e.g. `https://example.comundefined`), the proxy
returns a response with the error message. `got-scraping` only logs the
length of the message, which is quite useless for most applications.

Author: barjin

package-lock.json

@@ -16,7 +16,7 @@
     "types": "./dist/index.d.ts",
     "type": "module",
     "dependencies": {
-        "got": "^13.0.0",
+        "got": "^14.2.1",
         "header-generator": "^2.1.41",
         "http2-wrapper": "^2.2.0",
         "mimic-response": "^4.0.0",

package.json

@@ -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.`);
     }
 }
 

src/hooks/proxy.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}`;
@@ -42,8 +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)}`, { cause: head.toString('utf8') }));
                     socket.destroy();
                     return;
                 }

src/resolve-protocol.ts

@@ -6,6 +6,7 @@
 		"target": "ES2022",
 		"verbatimModuleSyntax": true,
 		"incremental": false,
+		"lib": ["DOM", "ESNext"],
 	},
 	"include": [
 		"src"