React batch updates for multiple setState() calls inside useEffect hook

Question

On this answer by Dan Abramov here on SO, I\'ve found out the following:

Does React keep the order for state updates?

Currently (React 16 and earl

Answer 1

Nice question. Here is additional info to complete @FranklinOcean answer.

Answer for current version of react, which is 16.8.3.

Based on the following codesandbox:

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Batched setStuff calls:

• Inline the component function block synchronously (I think it is equivalent to having an effect running before the other effects and without dependencies)
• In a useEffect block synchronously
• In a synthetic event handler synchronously (managed by react, such as onClick={handlerFunction})

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Non batched calls that will trigger a re-render each time:

• Any asynchronous code (promise/async function in any of the above use cases)
• Non synthetic event (event managed outside react lib)
• That includes XHR or other networks callbacks

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I'll try re-run the sandbox with future versions of react to see how it goes!