DeepNullable

Since 1.1.0

Make all properties nullable recursively.

Signature

type DeepNullable<T> = T extends (...args: any[]) => any
  ? T
  : T extends Map<infer K, infer V>
    ? Map<DeepNullable<K>, DeepNullable<V>>
    : T extends Set<infer V>
      ? Set<DeepNullable<V>>
      : T extends readonly (infer E)[]
        ? DeepNullable<E>[]
        : T extends object
          ? { [K in keyof T]: DeepNullable<T[K]> | null }
          : T | null

Parameters

Parameter	Description
T	The target type

Description

Recursively makes all properties in an object type nullable (adds | null).

Examples

Basic Usage

import type { DeepNullable } from 'uni-types'

interface Config {
  database: {
    host: string
    port: number
  }
}

type Nullable = DeepNullable<Config>
// { database: { host: string | null; port: number | null } | null }

With Nested Objects

interface User {
  profile: {
    name: string
    address: {
      city: string
      zip: string
    }
  }
}

type NullableUser = DeepNullable<User>
// All nested properties can be null

Related

• DeepOptional - Make all properties optional
• DeepNonNullable - Remove null from all properties