import { MessageFunctionType, Result } from '../types';
export interface IsFQDNErrors {
    TARGET_ARGUMENT_NOT_A_STRING: MessageFunctionType;
}
export declare const IS_FQDN_ERRORS: IsFQDNErrors;
/**
 *  IsFQDN Options
 */
export interface IsFQDNOptions {
    require_tld?: boolean;
    allow_underscores?: boolean;
    allow_trailing_dot?: boolean;
    allow_numeric_tld?: boolean;
    allow_wildcard?: boolean;
}
/**
 * Tests whether the `target` string is a FQDN
 *
 * @param target The target string
 * @param options The options
 *
 * ### Example
 * ```
 * expect(isFQDN('domain.com').value).toBeTruthy()
 * ```
 */
export declare function isFQDN(target: string, options: IsFQDNOptions): Result<boolean | undefined>;