API Overview

UntilJS provides a simple, Promise-based API for waiting on value changes.

Installation

pnpm

pnpm add untiljs

npm

npm install untiljs

yarn

yarn add untiljs

Quick Reference

Functions

Function	Description
until()	Main function to create an Until instance
createStore()	Create a reactive store for use with until

Types

Type	Description
WatchSource	Types of values that can be watched
Subscribable	Interface for subscribable objects
UntilToMatchOptions	Options for wait methods

Methods

Method	Description
toBe(value, options?)	Wait until value equals target
toMatch(condition, options?)	Wait until condition returns true
toBeTruthy(options?)	Wait until value is truthy
toBeNull(options?)	Wait until value is null
toBeUndefined(options?)	Wait until value is undefined
toBeNaN(options?)	Wait until value is NaN
changed(options?)	Wait until value changes
changedTimes(n, options?)	Wait until value changes n times
toContains(value, options?)	Wait until array contains value
not.*	Inverse of any method above

Basic Usage

import until from 'untiljs'

// Basic usage
let value = 0
setTimeout(() => { value = 5 }, 1000)

await until(() => value).toBe(5)

Return Value

All methods return a Promise that resolves to:

• The current value when the condition is met
• The current value on timeout (if throwOnTimeout is false)
• Rejects on timeout (if throwOnTimeout is true)

const result = await until(() => value).toBe(5)
console.log(result) // 5