@debugg-ai/debugg-ai-mcp/dist/services/ngrok/tunnelRegistry.js

Zero-Config, Fully AI-Managed End-to-End Testing for all code gen platforms.

/**
 * Cross-process tunnel registry.
 *
 * Lets multiple MCP server instances on the same machine discover and share
 * ngrok tunnels instead of each provisioning a duplicate for the same port.
 *
 * The file registry uses an atomic rename-write so concurrent processes never
 * see a partial JSON file.  All operations are best-effort — errors are
 * swallowed so a broken registry never blocks tunnel creation.
 */
import { existsSync, readFileSync, writeFileSync, renameSync } from 'fs';
import { tmpdir } from 'os';
import { join } from 'path';
// ── File-backed implementation (production) ───────────────────────────────────
const REGISTRY_FILE = join(tmpdir(), 'debugg-ai-tunnels.json');
export function createFileRegistry() {
    const store = {
        read() {
            try {
                if (!existsSync(REGISTRY_FILE))
                    return {};
                return JSON.parse(readFileSync(REGISTRY_FILE, 'utf8'));
            }
            catch {
                return {};
            }
        },
        write(data) {
            const tmp = `${REGISTRY_FILE}.${process.pid}.tmp`;
            try {
                writeFileSync(tmp, JSON.stringify(data));
                renameSync(tmp, REGISTRY_FILE);
            }
            catch {
                // best-effort
            }
        },
        isPidAlive(pid) {
            return checkPid(pid);
        },
        prune(opts) {
            return pruneRegistryData(store, opts);
        },
    };
    return store;
}
// ── In-memory implementation (tests / injectable) ─────────────────────────────
export function createInMemoryRegistry(isPidAliveImpl) {
    let data = {};
    const store = {
        read: () => ({ ...data }),
        write: (next) => { data = { ...next }; },
        isPidAlive: isPidAliveImpl ?? checkPid,
        prune: (opts) => pruneRegistryData(store, opts),
    };
    return store;
}
// ── No-op implementation (tests that don't exercise registry) ─────────────────
export const noopRegistry = {
    read: () => ({}),
    write: () => { },
    isPidAlive: () => false,
    prune: () => ({ pruned: 0, remaining: 0 }),
};
// ── Default selection ─────────────────────────────────────────────────────────
/**
 * Returns the appropriate registry for the current environment.
 * Tests (NODE_ENV=test) get the no-op registry; production gets file-backed.
 */
export function getDefaultRegistry() {
    return process.env.NODE_ENV === 'test' ? noopRegistry : createFileRegistry();
}
// ── Helpers ───────────────────────────────────────────────────────────────────
function checkPid(pid) {
    try {
        process.kill(pid, 0); // signal 0 = existence check, no signal sent
        return true;
    }
    catch {
        return false;
    }
}
/**
 * Shared prune logic — read, filter, write back. Used by both the file-backed
 * and in-memory implementations so the eviction policy lives in one place.
 *
 * Eviction rule: drop entries where EITHER the owner PID is dead OR the entry
 * hasn't been touched within `staleAfterMs`. The freshness check is what
 * defends against PID-reuse (bead 3th).
 */
function pruneRegistryData(store, opts) {
    const now = opts.nowMs ?? Date.now();
    const data = store.read();
    const next = {};
    let pruned = 0;
    for (const [port, entry] of Object.entries(data)) {
        const aliveAndFresh = store.isPidAlive(entry.ownerPid) &&
            (now - entry.lastAccessedAt) <= opts.staleAfterMs;
        if (aliveAndFresh) {
            next[port] = entry;
        }
        else {
            pruned++;
        }
    }
    if (pruned > 0)
        store.write(next);
    return { pruned, remaining: Object.keys(next).length };
}