Bug: using useState without changing the state generate a useless rerender

When using useState in a component, this component will rerender twice, whereas nor the state nor the props did change.

React version: 16.13.1

Steps To Reproduce

1. Create a dummy functionnal component
2. Create a state with useState

Link to code example: codesandbox

import React from "react";

let count = 0;

const App = () => {
  const [a] = React.useState("render");
  count++;
  console.log(a, count);
  return <div>{count}</div>;
};

export default App;

The current behavior

Logs are: render 1 render 2

The expected behavior

render 1

[Sharcoux]

Same problem. When removing React.StrictMode it solves the problem

When removing useState and useEffect it solves the problem,too.

Removing the component solves the problem too xD

[rachelnabors]

I can confirm this is fixed in https://github.com/facebook/react/pull/18547 and the fix will be included in React 17. To be clear, the component will still run twice, but the console.log will be disabled on the second run.