/**
 * Latency is what makes a mock exercise the states a real API forces an app
 * through — pending spinners, skeletons, optimistic UI, race conditions. The same
 * latency in a test suite is dead time, so the amount is per-environment and the
 * default under test is none.
 */
export type MockDelayInput = number | {
    /** Milliseconds under test. Defaults to `0`. */
    test?: number;
    /** Milliseconds everywhere else. Defaults to `0`. */
    dev?: number;
};
/**
 * True when running under a test runner: `NODE_ENV === 'test'` (vitest, jest) or
 * Vite's `MODE === 'test'`. Read defensively because neither `process` nor
 * `import.meta.env` exists in every environment this package runs in.
 */
export declare function isTestEnvironment(): boolean;
/** The pure resolution `mockDelay` applies, split out so both branches are testable. */
export declare function resolveMockDelay(input: MockDelayInput, isTest: boolean): number;
/**
 * Waits, in dev; resolves immediately under test unless a test delay is asked
 * for.
 *
 * ```ts
 * mock.get('/things', async ({ response }) => {
 *   await mockDelay(400);
 *   return response(200).json(things.list());
 * });
 *
 * // Keep a little latency under test, for a pending-state assertion.
 * await mockDelay({ dev: 400, test: 10 });
 * ```
 */
export declare function mockDelay(input?: MockDelayInput): Promise<void>;