without higher-order component

CommentList.js

import React, { Component } from "react";
import DataSource from "../DataSource";

const Comment = ({ comment }) => <>{comment}</>;

export class CommentList extends Component {
  constructor(props) {
    super(props);
    this.state = {
      data: DataSource.getComments()
    };
  }

  componentDidMount() {
    DataSource.addChangeListener(this.handleChange);
  }

  componentWillUnmount() {
    DataSource.removeChangeListener(this.handleChange);
  }

  handleChange = () => {
    this.setState({
      data: DataSource.getComments()
    });
  };

  render() {
    return (
      <>
        {this.props.data.map(comment => (
          <Comment comment={comment} key={comment.id} />
        ))}
      </>
    );
  }
}