proxy-agent 6.5.0

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:npm/proxy-agent@6.5.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/proxy-agent@6.5.0

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

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}

{
  "name": "sample-proxy-agent",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of proxy-agent",
  "main": "src/index.js",
  "dependencies": {
    "proxy-agent": "6.5.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/proxy-agent@6.5.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/proxy-agent@6.5.0"
  ]
}

const { ProxyAgent, proxies } = require('proxy-agent');

/**
 * Creates a new ProxyAgent instance with optional configuration.
 *
 * @param {import('proxy-agent').ProxyAgentOptions} [options] - Proxy agent options
 * @returns {ProxyAgent} Configured ProxyAgent instance
 */
function createProxyAgent(options) {
  return new ProxyAgent(options);
}

/**
 * Checks whether a given proxy protocol is supported by ProxyAgent.
 *
 * @param {string} protocol - Proxy protocol scheme (e.g. 'http', 'https', 'socks5')
 * @returns {boolean} True if supported
 */
function isSupportedProxyProtocol(protocol) {
  if (typeof protocol !== 'string') return false;
  const cleanProto = protocol.replace(/:$/, '').toLowerCase();
  return Object.prototype.hasOwnProperty.call(proxies, cleanProto);
}

/**
 * Resolves the underlying agent for a given request via the ProxyAgent instance.
 *
 * @param {ProxyAgent} agent - ProxyAgent instance
 * @param {object} req - Request object with getHeader and path
 * @param {object} [opts] - Connection options (e.g. { secureEndpoint: boolean })
 * @returns {Promise<import('http').Agent>} The underlying agent to use
 */
async function resolveAgent(agent, req, opts = {}) {
  if (!agent || typeof agent.connect !== 'function') {
    throw new TypeError('Expected a valid ProxyAgent instance');
  }
  return agent.connect(req, opts);
}

module.exports = {
  createProxyAgent,
  isSupportedProxyProtocol,
  resolveAgent,
  ProxyAgent,
  proxies
};

import assert from 'node:assert';
import http from 'node:http';
import https from 'node:https';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const {
  createProxyAgent,
  isSupportedProxyProtocol,
  resolveAgent,
  ProxyAgent,
  proxies
} = require('../src/index.js');

// 1. Export verification
assert.strictEqual(typeof ProxyAgent, 'function', 'ProxyAgent should be exported as a constructor function');
assert.strictEqual(typeof proxies, 'object', 'proxies dictionary should be exported');
assert.strictEqual(typeof createProxyAgent, 'function', 'createProxyAgent should be exported as a function');
assert.strictEqual(typeof isSupportedProxyProtocol, 'function', 'isSupportedProxyProtocol should be exported as a function');
assert.strictEqual(typeof resolveAgent, 'function', 'resolveAgent should be exported as a function');

// 2. Default instantiation
const defaultAgent = createProxyAgent();
assert(defaultAgent instanceof ProxyAgent, 'Should instantiate a ProxyAgent');
assert(defaultAgent.httpAgent instanceof http.Agent, 'Should configure default httpAgent');
assert(defaultAgent.httpsAgent instanceof https.Agent, 'Should configure default httpsAgent');
assert.strictEqual(typeof defaultAgent.connect, 'function', 'Should provide connect method');
assert.strictEqual(typeof defaultAgent.destroy, 'function', 'Should provide destroy method');

// 3. Custom routing callback
const routingAgent = createProxyAgent({
  getProxyForUrl: (url) => {
    if (url.includes('proxy-target.example.com')) {
      return 'http://127.0.0.1:8080';
    }
    if (url.includes('socks-target.example.com')) {
      return 'socks5://127.0.0.1:1080';
    }
    return '';
  }
});
assert.strictEqual(typeof routingAgent.getProxyForUrl, 'function', 'Should configure custom getProxyForUrl');

// 4. Fallback to direct agents
const reqDirect = {
  getHeader(name) {
    if (name.toLowerCase() === 'host') return 'direct.example.com';
    return undefined;
  },
  path: '/api/v1/direct'
};

const directHttp = await resolveAgent(routingAgent, reqDirect, { secureEndpoint: false });
assert.strictEqual(directHttp, routingAgent.httpAgent, 'Should return default httpAgent when no proxy matched');

const directHttps = await resolveAgent(routingAgent, reqDirect, { secureEndpoint: true });
assert.strictEqual(directHttps, routingAgent.httpsAgent, 'Should return default httpsAgent when no proxy matched');

// 5. Proxy routing for HTTP and SOCKS
const reqHttpProxy = {
  getHeader(name) {
    if (name.toLowerCase() === 'host') return 'proxy-target.example.com';
    return undefined;
  },
  path: '/api/v1/resource'
};

const proxiedHttp = await resolveAgent(routingAgent, reqHttpProxy, { secureEndpoint: false });
assert(proxiedHttp !== routingAgent.httpAgent, 'Proxied HTTP agent should differ from default direct agent');
assert.strictEqual(proxiedHttp.proxy.origin, 'http://127.0.0.1:8080', 'Proxied HTTP agent should point to proxy URL');

const reqSocksProxy = {
  getHeader(name) {
    if (name.toLowerCase() === 'host') return 'socks-target.example.com';
    return undefined;
  },
  path: '/api/v1/secure-resource'
};

const proxiedSocks = await resolveAgent(routingAgent, reqSocksProxy, { secureEndpoint: true });
assert(proxiedSocks !== routingAgent.httpsAgent, 'Proxied SOCKS agent should differ from default https agent');

// 6. Caching proxy agent instances
const cachedHttp = await resolveAgent(routingAgent, reqHttpProxy, { secureEndpoint: false });
assert.strictEqual(cachedHttp, proxiedHttp, 'Subsequent connect for same target should return cached agent instance');
assert.strictEqual(routingAgent.cache.size, 2, 'Cache contains created proxy agent instances');

// 7. Destroy cleanup
assert.doesNotThrow(() => {
  routingAgent.destroy();
}, 'Destroying ProxyAgent should execute cleanly');

// 8. Supported proxy protocols
assert.strictEqual(isSupportedProxyProtocol('http'), true, 'http protocol should be supported');
assert.strictEqual(isSupportedProxyProtocol('https'), true, 'https protocol should be supported');
assert.strictEqual(isSupportedProxyProtocol('socks5'), true, 'socks5 protocol should be supported');
assert.strictEqual(isSupportedProxyProtocol('pac+http'), true, 'pac+http protocol should be supported');
assert.strictEqual(isSupportedProxyProtocol('ftp'), false, 'ftp protocol should not be supported');
assert.strictEqual(isSupportedProxyProtocol('unknown'), false, 'unknown protocol should not be supported');

console.log('Contract assertions passed.');