/**
 * How long a test waits on a teardown before calling it hung. Derived, so
 * moving a ladder rung cannot turn these assertions into flakes.
 */
export declare const MAX_TEARDOWN_WAIT_MS: number;
/** Whether `pid` still exists (a reaped process's signal 0 throws ESRCH). */
export declare function alive(pid: number): boolean;
/** Poll until `predicate` holds or time runs out. */
export declare function waitFor(predicate: () => boolean, timeoutMs?: number): Promise<void>;
/**
 * The resolved value, or `"hung"` if `work` was still pending after `ms`.
 * A bounded assertion is the point: an unbounded `await` on a supervisor that
 * never tears down just hangs the test run instead of failing it.
 */
export declare function settleWithin<T>(work: Promise<T>, ms?: number): Promise<T | "hung">;