pure-parse/dist/guards/optional.d.ts

Strongly typed validation library that decouples type aliases from validation logic

import { Guard, OptionalGuard } from './Guard';
/**
 * Represent an optional property. Note that in TypeScript, optional properties may be assigned `undefined` or omitted entirely from the object.
 * @example
 * Wrap properties in `optional` to make them optional:
 * ```ts
 * type User = {
 *  id: number
 *  email?: string
 * }
 * const isUser = objectGuard<User>({
 *   id: isNumber,
 *   email: optionalGuard(isString),
 * })
 * isUser({ id: 123 }) // -> true
 * isUser({ id: 123, email: undefined }) // -> true
 * isUser({ id: 123, email: 'abc@test.com' }) // -> true
 * ```
 * @param guard
 */
export declare const optionalGuard: <T>(guard: Guard<T>) => OptionalGuard<T>;
/**
 * Create an optional property that also can be `null`. Convenient when creating optional nullable properties in objects. Alias for `optional(oneOfGuard(isNull, guard))`.
 * @param guard
 */
export declare const optionalNullableGuard: <T>(guard: Guard<T>) => OptionalGuard<T | null>;
/**
 * Create a union with `null`. Convenient when creating nullable properties in objects. Alias for `unionGuard(isNull, guard)`.
 * @param guard
 */
export declare const nullableGuard: <T>(guard: Guard<T>) => (data: unknown) => data is T | null;
/**
 * Create a union with `undefined`, which is different from optional properties. Alias for `unionGuard(isUndefined, guard)`.
 * @param guard
 */
export declare const undefineableGuard: <T>(guard: Guard<T>) => (data: unknown) => data is T | undefined;