import { MessageFunctionType, Result } from '../types';
export interface IsBeforeErrors {
    AFTER_ARGUMENT_NOT_A_DATE: MessageFunctionType;
    BEFORE_ARGUMENT_NOT_A_DATE: MessageFunctionType;
}
export declare const IS_BEFORE_ERRORS: IsBeforeErrors;
/**
 * Checks whether the `before` date comes before the `after` date
 *
 * @param before The before date
 * @param after The after date
 * @return true if the `before` date comes before the `after` date, false otherwise
 * @example
 * ```
 * expect(isBefore(new Date(1), new Date(2)).value).toBeTruthy()
 * ```
 */
export declare function isBefore(before: Date, after: Date): Result<boolean | undefined>;