Using empty string to prevent updating of dangerouslySetInnerHTML?

From @sebmarkbage's comment over in the React repo it sounds like dangerouslySetInnerHTML doesn't update the underlying DOM if it receives an empty string. I could also reproduce this: https://repl.it/repls/MotherlyPuzzlingComma

That's useful behavior for us in a server-rendering context where we don't need to ship the HTML to the client. But before merging that PR, I want to make sure this behavior is intended and not going away silently. And if so, should we maybe document it on the website?

首先檢視連結的 React issue 留言、repro，以及參照的 mozilla/kuma pull request，以確認空的 dangerouslySetInnerHTML 是否為預期行為。完成的標準是確認該行為，並決定是否應在 React 文件網站上加以說明。