toBeTruthy()

Wait until the value is truthy.

Signature

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

Parameters

options

• Type: UntilToMatchOptions
• Required: No

Options for timeout and comparison behavior.

Returns

A Promise that resolves to the current value when it's truthy.

What is Truthy?

In JavaScript, truthy values are values that evaluate to true in a boolean context:

• Non-empty strings: 'hello', 'false'
• Non-zero numbers: 1, -1, 3.14
• Objects: {}, []
• Functions: () => {}

Falsy values:

• false
• 0
• '' (empty string)
• null
• undefined
• NaN

Examples

Basic Usage

import until from 'untiljs'

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

const result = await until(() => data).toBeTruthy()
console.log(result) // { name: 'John' }

Waiting for Non-Null

import until from 'untiljs'

let user: User | null = null

fetch('/api/user')
  .then(res => res.json())
  .then(data => { user = data })

await until(() => user).toBeTruthy()
console.log('User loaded:', user)

With Timeout

import until from 'untiljs'

let data = null

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

if (result) {
  console.log('Data loaded:', result)
} else {
  console.log('Timed out waiting for data')
}

With Vue

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

const loading = ref(true)
const data = ref<string | null>(null)

async function fetchData() {
  loading.value = true

  setTimeout(() => {
    data.value = 'Hello World'
    loading.value = false
  }, 1000)

  // Wait for data to be truthy
  await until(data).toBeTruthy()

  console.log('Data loaded:', data.value)
}

With React (createStore)

import until, { createStore } from 'untiljs'

const dataStore = createStore<string | null>(null)

async function fetchData() {
  setTimeout(() => {
    dataStore.value = 'Hello World'
  }, 1000)

  await until(dataStore).toBeTruthy()
  console.log('Data loaded:', dataStore.value)
}

DOM Elements

import until from 'untiljs'

// Wait for element to exist
await until(() => document.getElementById('my-element')).toBeTruthy()

const element = document.getElementById('my-element')
console.log('Element found:', element)

See Also

• toBeNull()
• toBeUndefined()
• toMatch()