Interval.js

import { Component } from 'react'
import renderProps from '../utils/renderProps'

class Interval extends Component {
  state = {
    times: 0,
  }

  intervalId = undefined

  _clearIntervalIfNecessary = () => {
    if (this.intervalId) {
      this.intervalId = clearInterval(this.intervalId)
    }
  }

  _setIntervalIfNecessary = delay => {
    if (Number.isFinite(delay)) {
      this._clearIntervalIfNecessary()
      this.intervalId = setInterval(
        () => this.setState(s => ({ times: s.times + 1 })),
        delay
      )
    }
  }

  stop = () => {
    this._clearIntervalIfNecessary()
  }

  start = delay => {
    const _delay =
      typeof delay === 'number'
        ? delay
        : this.props.delay != null ? this.props.delay : 1000
    this._setIntervalIfNecessary(_delay)
  }

  toggle = () => {
    this.intervalId ? this.stop() : this.start()
  }

  componentDidMount() {
    this.start()
  }

  componentDidUpdate(prevProps) {
    if (prevProps.delay !== this.props.delay) {
      this.stop()
      this.start()
    }
  }

  componentWillUnmount() {
    this.stop()
  }

  render() {
    return renderProps(this.props, {
      start: this.start,
      stop: this.stop,
      toggle: this.toggle,
    })
  }
}

export default Interval