Registry / messaging / websocket-as-promised

websocket-as-promised

library3.0.1jsnpmunverified

A WebSocket client library providing a Promise-based API for connecting, disconnecting, and messaging with servers. Version 3.0.1 is the latest stable release. It supports both browser and Node.js environments with ESM and CommonJS modules. Key differentiators include built-in TypeScript types, support for raw, JSON, and binary data, and a request/response pattern. The library is actively maintained and requires a global Promise constructor or polyfill for older environments.

messaging

npm install websocket-as-promised

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · WEBSOCKET-AS-PROMI

websocket-as-promised

messagingjavascriptv3.0.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

WebSocketAsPromised

✓ import WebSocketAsPromised from 'websocket-as-promised'

✗ const WebSocketAsPromised = require('websocket-as-promised')

Default export; CommonJS require works in Node.js, but TypeScript types are better with ESM import.

WebSocketAsPromised

✓ import WebSocketAsPromised from 'websocket-as-promised'

✗ import { WebSocketAsPromised } from 'websocket-as-promised'

The library exports a single default class, not a named export. Named import will result in undefined.

WebSocketAsPromised type

✓ import WebSocketAsPromised from 'websocket-as-promised'

✗ import type WebSocketAsPromised from 'websocket-as-promised'

TypeScript type imports should use the default import syntax; the library provides type declarations alongside the class.

Shows how to create a WebSocket client with JSON packing, send a request and await response, then close connection.

import WebSocketAsPromised from 'websocket-as-promised'; const wsp = new WebSocketAsPromised('ws://example.com', { packMessage: data => JSON.stringify(data), unpackMessage: data => JSON.parse(data), extractMessageData: event => event.data, // for browser }); (async () => { try { await wsp.open(); const response = await wsp.sendRequest({ type: 'ping' }); console.log('Response:', response); } catch (err) { console.error('Error:', err); } finally { await wsp.close(); } })();

Debug

Known issues

gotchaWhen using the 'ws' package in Node.js, omitting extractMessageData option causes data to be undefined.

fix

Set extractMessageData: event => event in constructor options.

affects: >=0.0.0

gotchasendRequest() returns a promise that may never resolve if no matching response is received; ensure server sends a response with matching requestId.

fix

Define packMessage and unpackMessage options for automatic request/response tracking, or implement timeout logic.

affects: >=0.0.0

gotchaThe library expects a global Promise constructor; in environments without native Promise, install a polyfill.

fix

Install 'es6-promise' or similar polyfill, or use Node.js >=10 which includes native Promise.

affects: >=0.0.0

breakingVersion 3.0 removed the `onOpen`, `onClose`, `onError` event properties; use `onStatusChange` or `open()`, `close()` promises instead.

fix

Migrate from `wsp.onOpen.addListener(...)` to `wsp.onStatusChange.addListener(...)` or handle via `await wsp.open()`.

affects: >=3.0.0

Errors

Common errors & fixes

TypeError: Cannot read properties of undefined (reading 'data')

In Node.js with 'ws', the onmessage handler receives the WebSocket frame directly, not a MessageEvent.

fix

Add extractMessageData: event => event to constructor options.

Error: open() called when connection already open

Calling open() on an already opened WebSocket.

fix

Check wsp.isOpening or handle connection state before calling open().

Error: Request timeout

sendRequest() waiting for response but server never sent one with matching requestId.

fix

Ensure server sends a response with the same ID, or implement custom timeout logic using Promise.race.

Upgrade

Version history

3.0.1latest on npm

Audit

Dependencies

wsoptionalOptional WebSocket implementation for Node.js; required when using the 'ws' package instead of browser WebSocket.

websocketoptionalOptional WebSocket implementation for Node.js; provides W3C-compatible WebSocket client.

Agent activity

23 hits · last 30 days

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OpenAI (training)

Resources

githubgit://github.com/vitalets/websocket-as-promised ↗

packagewebsocket-as-promised ↗

homepagehttps://github.com/vitalets/websocket-as-promised#readme ↗