/**
 * Check if a file path has a valid extension
 * @param filePath The file path to check
 * @param validExtensions The valid extensions
 * @returns true if the file path has a valid extension
 * @example
 * checkFileExtension("test.geojson", ["geojson", "json"]) // true
 * checkFileExtension("test.txt", ["md"]) // false
 */
export declare const checkFileExtension: (filePath: string, validExtensions: string[]) => boolean;
/**
 * Format a file size to a human readable string
 * @param bytes The file size in bytes
 * @returns The formatted file size
 * @example
 * formatFileSize(1024) // "1.0 KB"
 * formatFileSize(1024 * 1024) // "1.0 MB"
 */
export declare const formatFileSize: (bytes: number | null) => string;