toBeNull()

Wait until the value is null.

Signature

toBeNull(options?: UntilToMatchOptions): Promise<T>

Parameters

options

• Type: UntilToMatchOptions
• Required: No

Options for timeout behavior.

Returns

A Promise that resolves to null when the value is null.

Examples

Basic Usage

import until from 'untiljs'

let data = { name: 'John' }
setTimeout(() => { data = null }, 500)

const result = await until(() => data).toBeNull()
console.log(result) // null

Waiting for Cleanup

import until from 'untiljs'

let user: User | null = { name: 'John' }

function logout() {
  user = null
}

setTimeout(logout, 1000)

await until(() => user).toBeNull()
console.log('User logged out')

With Timeout

import until from 'untiljs'

let data = { name: 'John' }

const result = await until(() => data).toBeNull({ timeout: 5000 })

With Vue

import { ref } from 'vue'
import until from 'untiljs'

const user = ref<User | null>({ name: 'John' })

async function logout() {
  user.value = null
  await until(user).toBeNull()
  console.log('Logout complete')
}

See Also

• toBeUndefined()
• toBeTruthy()
• not.toBeNull()