@escapace/deferred

A TypeScript implementation of the deferred pattern, providing explicit control over promise resolution and rejection.

Installation

pnpm add @escapace/deferred

Usage

import { Deferred } from '@escapace/deferred'

// Create a deferred
const deferred = new Deferred<string>()

// Access the promise
const promise = deferred.promise

// Resolve the deferred
deferred.resolve('success')

// Or reject it
// deferred.reject('error')

// Check state
console.log(deferred.isFulfilled()) // true
console.log(deferred.isResolved()) // true

API Reference

new Deferred<T>()

Creates a new deferred instance.

Properties:

• promise: Promise<T> - The underlying promise

Methods:

resolve(value?: PromiseLike<T> | T): void

Resolves the deferred with the given value.

reject(reason?: any): void

Rejects the deferred with the given reason.

isPending(): boolean

Returns true if the promise is still pending.

isFulfilled(): boolean

Returns true if the promise was resolved successfully.

isRejected(): boolean

Returns true if the promise was rejected.

isResolved(): boolean

Returns true if the deferred has been resolved or rejected.

Error Handling:

• Attempting to resolve or reject a deferred twice throws an error: "Deferred cannot be resolved twice"

License

MPL-2.0