feat(http-proxy-agent): emit 'proxyConnect' event

.changeset/http-proxy-agent-proxyconnect.md

@@ -0,0 +1,7 @@
+---
+"http-proxy-agent": minor
+---
+
+feat(http-proxy-agent): emit 'proxyConnect' event
+
+Adds `proxyConnect` event emission to `http-proxy-agent` for parity with `https-proxy-agent`. The event is emitted on both the request and the agent instance when the socket connects to the proxy server.

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

@@ -9,6 +9,10 @@ import type { OutgoingHttpHeaders } from 'http';
 
 const debug = createDebug('http-proxy-agent');
 
+export interface ProxyConnect {
+	socket: net.Socket;
+}
+
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 type Protocol<T> = T extends `${infer Protocol}:${infer _}` ? Protocol : never;
 
@@ -166,6 +170,11 @@ export class HttpProxyAgent<Uri extends string> extends Agent {
 		// connection via the `callback()` function throwing.
 		await once(socket, 'connect');
 
+		// Emit the 'proxyConnect' event for parity with https-proxy-agent
+		const connect: ProxyConnect = { socket };
+		req.emit('proxyConnect', connect);
+		this.emit('proxyConnect', connect, req);
+
 		return socket;
 	}
 }

packages/http-proxy-agent/test/test.ts

@@ -207,6 +207,36 @@ describe('HttpProxyAgent', () => {
 			expect(body.host).toEqual(httpServerUrl.hostname);
 		});
 
+		it('should emit "proxyConnect" event on the request', async () => {
+			httpServer.once('request', (req, res) => {
+				res.end(JSON.stringify(req.headers));
+			});
+
+			const agent = new HttpProxyAgent(proxyUrl);
+
+			const r = req(httpServerUrl, { agent });
+			const [connect] = await once(r, 'proxyConnect');
+			expect(connect.socket).toBeDefined();
+			expect(connect.socket.remoteAddress).toBeDefined();
+			const res = await r;
+			expect(res.statusCode).toEqual(200);
+		});
+
+		it('should emit "proxyConnect" event on the agent', async () => {
+			httpServer.once('request', (req, res) => {
+				res.end(JSON.stringify(req.headers));
+			});
+
+			const agent = new HttpProxyAgent(proxyUrl);
+
+			const r = req(httpServerUrl, { agent });
+			const [connect] = await once(agent, 'proxyConnect');
+			expect(connect.socket).toBeDefined();
+			expect(connect.socket.remoteAddress).toBeDefined();
+			const res = await r;
+			expect(res.statusCode).toEqual(200);
+		});
+
 		it('should work with `keepAlive: true`', async () => {
 			httpServer.on('request', (req, res) => {
 				res.end(JSON.stringify(req.headers));