DeepAssign

Since v1.3.0

Deep assign properties from one object type to another. Similar to Object.assign but operates recursively on nested objects, assigning all properties from the source to the target.

Signature

export type DeepAssign<T, U> = {
	[K in keyof T | keyof U]: K extends keyof U
		? U[K] extends Record<string, any>
			? K extends keyof T
				? T[K] extends Record<string, any>
					? DeepAssign<T[K], U[K]>
					: U[K]
				: U[K]
			: U[K]
		: K extends keyof T
			? T[K]
			: never
}

Parameters

Parameter	Description
T	The target object type
U	The source object type to assign from

Examples

Basic Usage

import type { DeepAssign } from 'uni-types'

type Target = { a: number; b: { c: string } }
type Source = { b: { d: boolean }; e: number }
type Result = DeepAssign<Target, Source>
// { a: number; b: { c: string; d: boolean }; e: number }

Overwriting Nested Properties

import type { DeepAssign } from 'uni-types'

type Config = { database: { host: string; port: number }; cache: { ttl: number } }
type Override = { database: { host: string }; cache: { enabled: boolean } }
type Assigned = DeepAssign<Config, Override>
// { database: { host: string; port: number }; cache: { ttl: number; enabled: boolean } }