import type { VFileData as Data, VFile } from 'vfile';
import type { MarkdownAstroData } from './types.js';
export declare class InvalidAstroDataError extends TypeError {
}
export declare function safelyGetAstroData(vfileData: Data): MarkdownAstroData | InvalidAstroDataError;
export declare function setVfileFrontmatter(vfile: VFile, frontmatter: Record<string, any>): void;