interface UpdateConfig {
    get(key: 'updateCheckLastAt'): string | undefined;
    set(key: 'updateCheckLastAt', value: string): void;
}
interface UpdateCommandLike {
    opts(): Record<string, unknown>;
    parent?: UpdateCommandLike | null;
}
export interface UpdateNoticeOptions {
    command?: UpdateCommandLike;
    now?: Date;
    currentVersion?: string;
    fetchImpl?: typeof fetch;
    stdoutIsTTY?: boolean;
}
export declare function maybeShowUpdateNotice(config: UpdateConfig, options?: UpdateNoticeOptions): Promise<void>;
export declare function shouldCheckForUpdates(config: UpdateConfig, options?: UpdateNoticeOptions): boolean;
export declare function commandRequestedJson(command: UpdateCommandLike | undefined): boolean;
export declare function fetchLatestVersion(fetchImpl: typeof fetch): Promise<string | null>;
export declare function compareSemver(a: string, b: string): number;
export {};