import { MessageFunctionType, Result } from '../types';
export interface IsPortErrors {
    TARGET_ARGUMENT_NOT_A_STRING: MessageFunctionType;
}
export declare const IS_PORT_ERRORS: IsPortErrors;
/**
 * Check if `target` is a valid port number
 *
 * ### Example
 * ```
 * expect(().value).toBeTruthy()
 * ```
 *
 * @param target The port number
 *
 * ### Example
 *
 * expect(isPort('4200').value).toBeTruthy()
 *
 */
export declare function isPort(target: string): Result<boolean | undefined>;