joplin/packages/app-desktop/gui/ResizableLayout/utils/layoutItemProp.ts

import findItemByKey from './findItemByKey';
import { LayoutItem } from './types';

export default function layoutItemProp(layout: LayoutItem, key: string, propName: string) {
	const item = findItemByKey(layout, key);
	if (!item) throw new Error(`Could not find layout item: ${key}`);
	return (item as any)[propName];
}