/**
 * .what = interface for useWhen with modifiers
 * .why = enables useWhen.only, useWhen.skip, etc.
 */
interface UseWhen {
    <T>(desc: string, fn: () => T): T;
    only: <T>(desc: string, fn: () => T) => T;
    skip: <T>(desc: string, fn: () => T) => T;
    skipIf: (condition: boolean) => <T>(desc: string, fn: () => T) => T;
    runIf: (condition: boolean) => <T>(desc: string, fn: () => T) => T;
}
/**
 * .what = execute a fn synchronously and capture its return value for sibling blocks
 * .why = enables sharing operation results across sequential blocks without let declarations
 * .note = unlike useThen, does not create a test block - executes immediately during collection
 */
export declare const useWhen: UseWhen;
export {};