typelevel-assert

<TypeLevel> Assert provides convenient assertions for type-level programming.

Usage

Installation

``sh
npm i -D typelevel-assert
`

Start to code (try it out)

`ts
import { assertType, Is } from 'typelevel-assert';

type Hi = Hi ${T}!;

assertType, 'Hi TypeLevel!'>>();
`

API

The assertType() assertion accepts a type parameter T.

* ✅ The compiler succeeds, if T is true
* ❌ The compiler fails, if T is not true

<TypeLevel> Assert has the following built-in type predicates that can be used with assertType:

| type | description |
| --- | --- |
| And | true if both C1 and C2 are true, false otherwise |
| Or | true if any of C1 or C2 is true, false otherwise |
| Not | true if C is false, true otherwise |
| Equals | And, Extends> |
| Extends | syntactic sugar for [T1] extends [T2] ? true : false |
| Is | true if T1 is exactly T2`, false otherwise |