export declare type FilesValidator<ErrorType = string> = (files: ReadonlyArray<File>) => ReadonlyArray<ErrorType | string | undefined> | ErrorType | string | undefined;
/**
 * Factory method for creating a common file type validator.
 *
 * @param {string} accept - It is the same as 'accept' attribute for HTML <input>.
 * @param {function} getError - A callback function for generating a customised user error.
 */
export declare function createFileTypeValidator<ErrorType = string>({ accept, getError, }: {
    accept: string;
    getError?: (file: File) => ErrorType;
}): FilesValidator<ErrorType>;
/**
 * Factory method for creating a common total selection size validator.
 *
 * @param {number} maxSize - Max selection size in bytes.
 * @param {function} getError - A callback function for generating a customised user error.
 */
export declare function createTotalSizeValidator<ErrorType = string>({ maxSize, getError, }: {
    maxSize: number;
    getError?: (totalSize: number) => ErrorType;
}): FilesValidator<ErrorType>;