'use strict'; const common = require('../common'); const assert = require('assert'); const cp = require('child_process'); const net = require('net'); if (process.argv[2] === 'child') { process.stdout.write('this should be ignored'); process.stderr.write('this should not be ignored'); const pipe = new net.Socket({ fd: 4 }); process.on('disconnect', () => { pipe.unref(); }); pipe.setEncoding('utf8'); pipe.on('data', (data) => { process.send(data); }); } else { assert.throws(() => { cp.fork(__filename, { stdio: ['pipe', 'pipe', 'pipe', 'pipe'] }); }, /Forked processes must have an IPC channel/); let ipc = ''; let stderr = ''; const buf = Buffer.from('data to send via pipe'); const child = cp.fork(__filename, ['child'], { stdio: [0, 'ignore', 'pipe', 'ipc', 'pipe'] }); assert.strictEqual(child.stdout, null); child.on('message', (msg) => { ipc += msg; if (ipc === buf.toString()) { child.disconnect(); } }); child.stderr.on('data', (chunk) => { stderr += chunk; }); child.on('exit', common.mustCall((code, signal) => { assert.strictEqual(code, 0); assert.strictEqual(signal, null); assert.strictEqual(stderr, 'this should not be ignored'); })); child.stdio[4].write(buf); }