roam-research-mcp/build/utils/net.js

MCP server and CLI for Roam Research

import { createServer } from 'node:net';
/**
 * Checks if a given port is currently in use.
 * @param port The port to check.
 * @param host Optional host to probe. When omitted, probes the wildcard address
 *   (any interface). Pass the host you intend to bind — a wildcard probe and a
 *   host-specific bind disagree in both directions, so the two must match or
 *   the answer is about a port nobody is going to open.
 * @returns A promise that resolves to true if the port is in use, and false otherwise.
 */
export function isPortInUse(port, host) {
    return new Promise((resolve) => {
        const server = createServer();
        server.once('error', (err) => {
            if (err.code === 'EADDRINUSE') {
                resolve(true);
            }
            else {
                // Handle other errors if necessary, but for this check, we assume other errors mean the port is available.
                resolve(false);
            }
        });
        server.once('listening', () => {
            server.close();
            resolve(false);
        });
        if (host) {
            server.listen(port, host);
        }
        else {
            server.listen(port);
        }
    });
}
// `findAvailablePort` lived here until 3.1.0. It existed so stdio mode could
// drift to a free port when 8088 was taken, and it has no caller now that stdio
// opens no socket: `--server` binds the exact configured port and fails loudly
// rather than drifting, because a shared daemon must keep a stable URL.
// Anything reaching for it again probably wants that failure instead.