CloseEvent
A CloseEvent is sent to clients using WebSockets when the connection is closed. This is delivered to the listener indicated by the WebSocket object's onclose attribute.
interface CloseEvent extends Event {
readonly code: number;
readonly reason: string;
readonly wasClean: boolean;
}var CloseEvent: {
prototype: CloseEvent;
new (type: string, eventInitDict?: CloseEventInit): CloseEvent;
};