[https-proxy-agent] Support SNI as default for proxy servers (#237)

Author: unhappychoice

.changeset/four-teachers-peel.md

@@ -0,0 +1,5 @@
+---
+"https-proxy-agent": patch
+---
+
+Support SNI for proxy servers

packages/https-proxy-agent/src/index.ts

@@ -91,7 +91,11 @@ export class HttpsProxyAgent<Uri extends string> extends Agent {
 		let socket: net.Socket;
 		if (proxy.protocol === 'https:') {
 			debug('Creating `tls.Socket`: %o', this.connectOpts);
-			socket = tls.connect(this.connectOpts);
+			const servername = this.connectOpts.servername || this.connectOpts.host;
+			socket = tls.connect({
+				...this.connectOpts,
+				servername: servername && net.isIP(servername) ? undefined : servername
+			});
 		} else {
 			debug('Creating `net.Socket`: %o', this.connectOpts);
 			socket = net.connect(this.connectOpts);