src/use-interval.js


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// lifted from here:
// https://overreacted.io/making-setinterval-declarative-with-react-hooks/
import { useEffect, useRef } from 'react'

export const useInterval = (callback, delay) => {
  const savedCallback = useRef()

  // Remember the latest callback.
  useEffect(
    () => {
      savedCallback.current = callback
    },
    [callback]
  )

  // Set up the interval.
  useEffect(
    () => {
      function tick() {
        savedCallback.current()
      }
      if (delay !== null) {
        let id = setInterval(tick, delay)
        return () => clearInterval(id)
      }
    },
    [delay]
  )
}