js/globals/websocket

js/globals/websocket.ts

internal:globals/websocket — the WHATWG WebSocket global surface.

This module is the aggregation point for the browser-compatible WebSocket API. It re-exports four symbols and installs none of them itself: the globals bootstrap (internal:globals/global) pulls them from here and binds WebSocket, CloseEvent, and ErrorEvent onto globalThis, while MessageEvent is shared with the messaging subsystem. Application code should reach these through the globals rather than importing this specifier directly.

The re-exported surface is:

• WebSocket — the client class. Constructing one opens a connection to a ws:/wss: URL and drives it through the standard readyState lifecycle (CONNECTING → OPEN → CLOSING → CLOSED), delivering frames as message events and dispatching open, error, and close.
• CloseEvent — dispatched as the close event; carries the numeric close code, the reason string, and whether the closing handshake was clean.
• ErrorEvent — dispatched as the error event when the connection fails.
• MessageEvent — the shared event type carrying inbound frame payloads on event.data (a string for text frames, a Blob or ArrayBuffer for binary frames per binaryType).

The lower-level server/client engine (WebSocketConnection), the WebSocketError type, and the accept/connect option interfaces live in fino:net/http/websocket; server-side upgrades flow through the serve() handler rather than through this global. Reach for this module's exports when you want the portable, spec-shaped client; reach for the engine when you are accepting or multiplexing connections on the server.

WebSocket API: https://websockets.spec.whatwg.org/

const ws = new WebSocket('wss://example.com/ws', ['chat.v1']);
ws.binaryType = 'arraybuffer';

ws.onopen = () => ws.send('hello');
ws.onmessage = (event) => console.log('frame:', event.data);
ws.onerror = (event) => console.error('socket error:', event.message);
ws.onclose = (event) => console.log(`closed ${event.code}: ${event.reason}`);

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