let%browser_only mockInitWebsocket: unit => unit = () => [%mel.raw {| function mockInitWebsocket() { console.log("Load JS"); } |} ]; mockInitWebsocket(); let element = Webapi.Dom.Document.querySelector("#root", Webapi.Dom.document); switch (element) { | Some(el) => let _ = ReactDOM.Client.hydrateRoot(el, ); (); | None => Js.log("No root element found") };