nullishAsync

Creates a nullish schema.

const Schema = v.nullishAsync<TWrapped, TDefault>(wrapped, default_);

Generics

• TWrapped extends BaseSchema<unknown, unknown, BaseIssue<unknown>> | BaseSchemaAsync<unknown, unknown, BaseIssue<unknown>>
• TDefault extends DefaultAsync<TWrapped, null | undefined>

Parameters

• wrapped TWrapped
• default_ TDefault

Explanation

With nullishAsync the validation of your schema will pass undefined and null inputs, and if you specify a default_ input value, the schema will use it if the input is undefined or null. For this reason, the output type may differ from the input type of the schema.

Note that nullishAsync accepts undefined or null as an input. If you want to accept only null inputs, use nullableAsync, and if you want to accept only undefined inputs, use optionalAsync instead. Also, if you want to set a default output value for any invalid input, you should use fallbackAsync instead.

Returns

• Schema NullishSchemaAsync<TWrapped, TDefault>

Examples

The following examples show how nullishAsync can be used.

Nullish username schema

Schema that accepts a unique username, undefined or null.

By using a function as the default_ parameter, the schema will return a unique username from the function call each time the input is undefined or null.

import { getUniqueUsername, isUsernameUnique } from '~/api';

const NullishUsernameSchema = v.nullishAsync(
  v.pipeAsync(
    v.string(),
    v.nonEmpty(),
    v.checkAsync(isUsernameUnique, 'The username is not unique.')
  ),
  getUniqueUsername
);

New user schema

Schema to validate new user details.

import { isEmailUnique, isUsernameUnique } from '~/api';

const NewUserSchema = v.objectAsync({
  email: v.pipeAsync(
    v.string(),
    v.email(),
    v.checkAsync(isEmailUnique, 'The email is not unique.')
  ),
  username: v.nullishAsync(
    v.pipeAsync(
      v.string(),
      v.nonEmpty(),
      v.checkAsync(isUsernameUnique, 'The username is not unique.')
    )
  ),
  password: v.pipe(v.string(), v.minLength(8)),
});

/*
  The input and output types of the schema:
    {
      email: string;
      password: string;
      username?: string | null | undefined;
    }
*/

Username schema

Schema that accepts a unique username.

import { isUsernameUnique } from '~/api';

const UsernameSchema = v.unwrap(
  // Assume this schema is from a different file and is reused here
  v.nullishAsync(
    v.pipeAsync(
      v.string(),
      v.nonEmpty(),
      v.checkAsync(isUsernameUnique, 'The username is not unique.')
    )
  )
);

Related

The following APIs can be combined with nullishAsync.

Schemas

• any,
• array,
• bigint,
• blob,
• boolean,
• custom,
• date,
• enum,
• file,
• function,
• instance,
• intersect,
• lazy,
• literal,
• looseObject,
• looseTuple,
• map,
• nan,
• never,
• nonNullable,
• nonNullish,
• nonOptional,
• null,
• nullable,
• nullish,
• number,
• object,
• objectWithRest,
• optional,
• picklist,
• promise,
• record,
• set,
• strictObject,
• strictTuple,
• string,
• symbol,
• tuple,
• tupleWithRest,
• undefined,
• undefinedable,
• union,
• unknown,
• variant,
• void

Methods

• config,
• getDefault,
• getFallback,
• unwrap

Actions

• brand,
• check,
• description,
• metadata,
• partialCheck,
• rawCheck,
• rawTransform,
• readonly,
• title,
• transform

Utils

• entriesFromList,
• isOfKind,
• isOfType

Async

• arrayAsync,
• checkAsync,
• customAsync,
• fallbackAsync,
• getDefaultsAsync,
• getFallbacksAsync,
• intersectAsync,
• lazyAsync,
• looseObjectAsync,
• looseTupleAsync,
• mapAsync,
• nonNullableAsync,
• nonNullishAsync,
• nonOptionalAsync,
• nullableAsync,
• objectAsync,
• objectWithRestAsync,
• optionalAsync,
• parseAsync,
• parserAsync,
• partialCheckAsync,
• pipeAsync,
• rawCheckAsync,
• rawTransformAsync,
• recordAsync,
• safeParseAsync,
• safeParserAsync,
• setAsync,
• strictObjectAsync,
• strictTupleAsync,
• transformAsync,
• tupleAsync,
• tupleWithRestAsync,
• undefinedableAsync,
• unionAsync,
• variantAsync