gistfile1.txt

function DrawingComponent(props: DrawingComponentProps) {
  ...
  const [histories, setHistories] = useState<Array<History>>([]);

  ...

  function clear() {
    layerRef.current?.destroyChildren();
    layerRef.current?.clear();

    console.log(histories);
    setHistories([...histories, { mode: "clear", startTime: Date.now() }]);
    console.log(histories);
    if (lastDrawMode === "brush") {
      console.log("draw");
      drawLine();
    } else {
      eraseLine();
    }
  }
  
  ...
  render(
    <Button variant="secondary" onClick={clear}>
      Clear
    </Button>
  );
}