import React from 'react';
import { createGlobalState } from 'react-hooks-global-state';

const initialState = { counter: 0 };
const { GlobalStateProvider, useGlobalState } = createGlobalState(initialState);

const Counter = () => {
  const [value, update] = useGlobalState('counter');
  return (
    <div>
      <span>Counter: {value}</span>
      <button onClick={() => update(v => v + 1)}>+1</button>
      <button onClick={() => update(v => v - 1)}>-1</button>
    </div>
  );
};

const App = () => (
  <GlobalStateProvider>
    <Counter />
    <Counter />
  </GlobalStateProvider>
);