monorepo/kifu/pwa/src/main.ts

import { GoBoard } from "./components/Board";
import { CoreApi, initCore } from "./coreApi";

window.customElements.define("go-board", GoBoard, { extends: "canvas" });

declare global {
  interface HTMLElementTagNameMap {
    "go-board": GoBoard;
  }
}

const main = async () => {
  let coreApi = await initCore();
  let response = await coreApi.playingField();
  console.log("playing field response: ", response);

  const root = document.getElementById("root");
  if (!root) {
    alert("could not retrieve the app root container");
    return;
  }

  const board = document.createElement("canvas", { is: "go-board" });
  console.log("constructed board: ", board);
  root.appendChild(board);
};

main();