<code>"render 0"</code>: logged the first time the DOM is rendered
Then the click event happens
<code>"handler"</code>: logged when the handler for the click fires
<code>"render 1"</code>: logged first because <code>flushSync</code> causes the DOM to synchronously get re-rendered with the new state
<code>"handler 0"</code>: logged after <code>flushSync</code>, but using the state value that was available when this function first initialized

Explanation

What does the code snippet to the right output by console.log?…