An assertion function that throws when condition is false. message can be a string or a lazy callback.

Install

npm install --save @yozora/invariant

Usage

• Syntax

  function invariant(
    condition: boolean,
    message?: string | (() => string),
  ): asserts condition

• Demo

  import invariant from '@yozora/invariant'
  
  invariant(typeof window !== 'undefined', '`window` is not defined.')

Related

• homepage