@nx/module-federation/dist/src/utils/port-utils.js

The Nx Plugin for Module Federation contains executors and utilities that support building applications using Module Federation.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.isPortInUse = isPortInUse;
const net_1 = require("net");
/**
 * Check if a port is in use by attempting to bind to it. Binding is local and
 * resolves immediately, so unlike a connection-based check it never stalls on
 * the OS TCP connect timeout when `localhost` resolves to an unreachable address
 * (e.g. IPv6 `::1`) -- the cause of the `nx serve` hang in #33909.
 */
function isPortInUse(port, host = 'localhost') {
    return new Promise((resolve) => {
        const server = (0, net_1.createServer)();
        server.once('error', (err) => {
            resolve(err.code === 'EADDRINUSE');
        });
        server.once('listening', () => {
            server.close(() => resolve(false));
        });
        server.listen(port, host);
    });
}