Mutable

Since 1.1.0

Remove readonly from all properties recursively.

Signature

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

Parameters

Parameter	Description
T	The target type

Description

Recursively removes readonly modifiers from all properties.

Examples

Basic Usage

import type { Mutable } from 'uni-types'

interface Config {
  readonly database: {
    readonly host: string
    readonly ports: readonly number[]
  }
}

type Writable = Mutable<Config>
// { database: { host: string; ports: number[] } }

With Readonly Arrays

type ReadonlyArray = readonly string[]
type WritableArray = Mutable<ReadonlyArray>  // string[]

Converting Frozen Objects

interface FrozenConfig {
  readonly apiKey: string
  readonly endpoints: readonly {
    readonly url: string
    readonly method: string
  }[]
}

type EditableConfig = Mutable<FrozenConfig>
// All readonly removed, can now modify

Related

• Immutable - Make all properties readonly
• DeepMutable - Make all properties mutable