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

[abhu85]

Summary

Fixes #368 - Emit the proxyConnect event for http-proxy-agent for parity with https-proxy-agent.

This PR adds proxyConnect event emission to http-proxy-agent. The event is emitted on both the request and the agent instance when the socket connects to the proxy server.

Changes

• Added ProxyConnect interface with socket property
• Emit proxyConnect event on the request after socket connects
• Emit proxyConnect event on the agent instance after socket connects
• Added test cases for both event emissions

Event Payload

Since http-proxy-agent doesn't use the CONNECT method (it sends requests directly through the proxy), the event payload is different from https-proxy-agent. The payload includes:

interface ProxyConnect {
  socket: net.Socket;
}

This gives users access to the connected socket so they can inspect connection details like remoteAddress, localPort, etc.

Usage Example

import { HttpProxyAgent } from 'http-proxy-agent';

const agent = new HttpProxyAgent('http://proxy:8080');

// Listen on the request
const req = http.request(url, { agent });
req.on('proxyConnect', (connect) => {
  console.log('Connected to proxy:', connect.socket.remoteAddress);
});

// Or listen on the agent
agent.on('proxyConnect', (connect, req) => {
  console.log('Proxy connection established');
});

Test Cases

• should emit "proxyConnect" event on the request
• should emit "proxyConnect" event on the agent

[changeset-bot]

🦋 Changeset detected

Latest commit: 78c1edf

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
http-proxy-agent	Minor

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