Method constructor

src/websocket.ts:46–89

(webSocket: WebSocket)

 */
export class WebSocketTransport<T extends string | ArrayBuffer = string> {
  constructor (webSocket: WebSocket) {
    this.#webSocket = webSocket;

    // Always set binaryType — harmless for string mode, required for ArrayBuffer mode.
    webSocket.binaryType = "arraybuffer";

    if (webSocket.readyState === WebSocket.CONNECTING) {
      this.#sendQueue = [];
      webSocket.addEventListener("open", event => {
        try {
          for (let message of this.#sendQueue!) {
            webSocket.send(message);
          }
        } catch (err) {
          this.#receivedError(err);
        }
        this.#sendQueue = undefined;
      });
    }

    webSocket.addEventListener("message", (event: MessageEvent<any>) => {
      if (this.#error) {
        // Ignore further messages.
      } else if (typeof event.data === "string" || event.data instanceof ArrayBuffer) {
        if (this.#receiveResolver) {
          this.#receiveResolver(event.data as T);
          this.#receiveResolver = undefined;
          this.#receiveRejecter = undefined;
        } else {
          this.#receiveQueue.push(event.data as T);
        }
      } else {
        this.#receivedError(new TypeError("Received unexpected message type from WebSocket."));
      }
    });

    webSocket.addEventListener("close", (event: CloseEvent) => {
      this.#receivedError(new Error(`Peer closed WebSocket: ${event.code} ${event.reason}`));
    });

    webSocket.addEventListener("error", (event: Event) => {
      this.#receivedError(new Error(`WebSocket connection failed.`));
    });
  }

  #webSocket: WebSocket;
  #sendQueue?: T[];  // only if not opened yet