propTypes // Extending JavaScript with ease (beginner level tutorial)

propTypes.js

import React from 'react'
import PropTypes from 'react-proptypes'

class MyComponent extends React.Component {
  // render logic here
}

MyComponent.propTypes = {
  collectorGroup: PropTypes.shape({
    target_count: PropTypes.number.isRequired,
    // a lot of other object properties here
  })
}

export default MyComponent