/**
 * Checks whether a TCP port can be bound on a given host (i.e. the port is free).
 *
 * Attempts to bind a throwaway server to `host:port`; resolves `true` if the bind
 * succeeds (the server is closed immediately) and `false` if it fails (e.g. the port
 * is still held by another process or socket).
 *
 * @param host The host/address to bind on (e.g. "127.0.0.2")
 * @param port The port to test
 * @returns A promise resolving to `true` if the port is free, `false` otherwise
 */
export declare function isPortFree(host: string, port: number): Promise<boolean>;
/**
 * Polls until every `host:port` in `ports` is free, or `timeoutMs` elapses.
 *
 * Unlike binding to an ephemeral port (which only proves the *address* is usable), this
 * verifies the specific fixed ports a Harper instance binds are actually released, which
 * is what the next test suite needs before it can reuse the address.
 *
 * @param host The host/address the ports are bound on (e.g. "127.0.0.2")
 * @param ports The fixed ports to wait on
 * @param timeoutMs Maximum time to wait for all ports to become free
 * @param pollIntervalMs Delay between polls (default 100ms)
 * @returns `true` if all ports became free within the timeout, `false` if it gave up
 */
export declare function waitForPortsFree(host: string, ports: number[], timeoutMs: number, pollIntervalMs?: number): Promise<boolean>;