/** How many consecutive ports to try before giving up. */
export declare const MAX_PORT_FALLBACK_ATTEMPTS = 10;
/** The highest port a TCP listener can bind. */
export declare const MAX_TCP_PORT = 65535;
/** True when `error` means "that port is taken", on either Deno or Node. */
export declare function isPortInUseError(error: unknown): boolean;
/**
 * True when `error` means "this host has no address in that family at all",
 * rather than "that port is taken".
 *
 * The two have to be told apart, because probing a family a host does not have
 * must not make every port look busy: an IPv4-only CI container or a machine
 * with IPv6 disabled would otherwise never find a free port to fall back to.
 */
export declare function isAddressFamilyUnavailableError(error: unknown): boolean;
/**
 * Binds `port` on every loopback family the dev server might use, and releases
 * it again, to see whether the dev server could have it.
 *
 * A port counts as available only when nothing holds it on *any* of those
 * addresses - see `PROBE_HOSTNAMES` for why one family is not enough. A family
 * the host does not have is skipped rather than counted as a collision.
 *
 * The Deno runtime is read through `getDenoRuntime()` rather than through the
 * `Deno` global directly: dnt rewrites every bare `Deno.` reference in the
 * published npm build into `@deno/shim-deno`, whose Node-backed `listen()`
 * reads `server._handle.fd` - null under Deno's `node:net`. A CLI installed
 * with `deno install -gArf npm:veryfront` runs that build on a real Deno, so
 * the shim was reached and `veryfront dev` died on "Cannot read properties of
 * null (reading 'fd')" before it ever printed a URL.
 */
export declare function isPortAvailable(port: number): Promise<boolean>;
/**
 * Returns `requestedPort`, or the first free port after it.
 *
 * Port 0 means "any free port", but it cannot be passed through: everything
 * downstream - the MCP port, `VERYFRONT_DEV_PORT`, the module server URL, the
 * printed `http://localhost:<port>` - is derived from the number the dev server
 * is handed, so handing it 0 lets the OS pick a port nothing else is told
 * about. It is resolved to a concrete ephemeral port here instead, and checked
 * with `probe` like any other candidate because the OS pool is per address
 * family while the dev server needs the port free on all of them.
 *
 * The scan stops at `MAX_TCP_PORT`: a runtime rejects port 65536 as an invalid
 * port rather than as an address in use, so scanning past the end of the range
 * would let that raw error escape instead of the `PORT_IN_USE` below.
 * `requestedPort` itself is always probed, so an out-of-range `--port` still
 * surfaces the runtime's own complaint about the value the user passed.
 *
 * Throws `PORT_IN_USE` - whose suggestion names `--port` - once the whole scan
 * range is taken.
 */
export declare function findAvailablePort(requestedPort: number, maxAttempts?: number, probe?: (port: number) => Promise<boolean>): Promise<number>;
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