Class OneWayWebSocket

site/src/utils/OneWayWebSocket.ts:81–226

}

export class OneWayWebSocket<TData = unknown>
	implements OneWayWebSocketApi<TData>
{
	readonly #socket: WebSocket;
	readonly #errorListeners = new Set<(e: Event) => void>();
	readonly #messageListenerWrappers = new Map<
		OneWayEventCallback<TData, "message">,
		WebSocketMessageCallback
	>();

	constructor(init: OneWayWebSocketInit) {
		const {
			apiRoute,
			searchParams,
			serverProtocols,
			binaryType = "blob",
			location = window.location,
			websocketInit = defaultInit,
		} = init;

		if (
			!apiRoute.startsWith("/api/v2/") &&
			!apiRoute.startsWith("/api/experimental")
		) {
			throw new Error(
				`API route '${apiRoute}' does not begin with '/api/v2/' or '/api/experimental'`,
			);
		}

		const formattedParams =
			searchParams instanceof URLSearchParams
				? searchParams
				: new URLSearchParams(searchParams);
		const paramsString = formattedParams.toString();
		const paramsSuffix = paramsString ? `?${paramsString}` : "";
		const wsProtocol = location.protocol === "https:" ? "wss:" : "ws:";
		const url = `${wsProtocol}//${location.host}${apiRoute}${paramsSuffix}`;

		this.#socket = websocketInit(url, serverProtocols);
		this.#socket.binaryType = binaryType;
	}

	get url(): string {
		return this.#socket.url;
	}

	addEventListener<TEvent extends WebSocketEventType>(
		event: TEvent,
		callback: OneWayEventCallback<TData, TEvent>,
	): void {
		if (this.#socket.readyState === WebSocket.CLOSED) {
			return;
		}

		// Not happy about all the type assertions, but there are some nasty
		// type contravariance issues if you try to resolve the function types
		// properly. This is actually the lesser of two evils
		const looseCallback = callback as OneWayEventCallback<