RequireNotNullish

Since 1.3.0

Ensure type is not null or undefined.

Signature

type RequireNotNullish<T> = null extends T ? never : undefined extends T ? never : T

Parameters

Parameter	Description
T	The type to check

Examples

Basic Usage

import type { RequireNotNullish } from 'uni-types'

type Result = RequireNotNullish<string> // string
type FailedNull = RequireNotNullish<null> // never
type FailedUndefined = RequireNotNullish<undefined> // never

With Union Types

type MaybeString = string | null | undefined
type StrictString = RequireNotNullish<MaybeString> // never (contains null/undefined)
type OptionalString = string | undefined
type NoUndefined = RequireNotNullish<OptionalString> // never

With Generic Types

type NonNullish<T> = RequireNotNullish<T>
type SafeValue = NonNullish<number> // number
type UnsafeValue = NonNullish<number | null> // never

Related

• AssertNotNil - Assert type is not never
• RequireArray - Ensure type is an array