WebSocketCloseInfo

type WebSocketCloseInfo =
  | { kind: "closed"; code?: number; reason?: string; wasClean?: boolean }
  | {
      kind: "aborted";
      cause?: unknown;
      code?: number;
      reason?: string;
      wasClean?: boolean;
    }
  | {
      kind: "error";
      cause: unknown;
      code?: number;
      reason?: string;
      wasClean?: boolean;
    };

What session.closed resolves with, once the session has ended for good.

• closed: the session ended normally, including a manual session.close().

• aborted: the session was cancelled; cause is the abort reason.

• error: the session failed; cause is required.

• code, reason, and wasClean come from the native close event when one was observed. A manual session.close(code, reason) fills code and reason when the close event does not.