Gotta get them dots!

Dots.js

import React from 'react'

class Dots extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      dots: '',
      timerID: null,
    }
  }

  increaseDots = () => {
    let { dots } = this.state
    dots = dots.length > 2 ? '' : dots + '.'
    this.setState({ dots })
  }

  componentWillMount() {
    const timerID = setInterval(() => {
      this.increaseDots()
    }, 1000)
    this.setState({ timerID })
  }

  componentWillUnmount() {
    clearInterval(this.state.timerID)
  }

  render() {
    return <span>{this.state.dots}</span>
  }
}

export default Dots