willunmount-class.tsx

import React, { Component } from 'react'

class WillUnmount extends Component {
  componentDidMount() {
    console.log('Eu estou montado')
  }

  componentWillUnmount() {
    console.log('Vou desmontar')
  }

  render() {
    return (
      <>
        ...Content
      </>
    )
  }
}

export default WillUnmount