updated with Contentful API call

Home.js

import React from 'react';
import { createClient } from 'contentful';

class Home extends React.Component {
  state = {
    posts: []
  };

  componentWillMount() {
    const client = createClient({
      space: process.env.REACT_APP_SPACE_ID,
      accessToken: process.env.REACT_APP_ACCESS_TOKEN
    });

    client
      .getEntries({})
      .then(response => {
        this.setState({
          posts: response.items
        });
      })
      .catch(console.error);
  }

  render() {
    if (!this.state.posts.length) return <p>No posts found.</p>;

    return this.state.posts.map(post => {
      console.log(post);
      return <p>Post</p>;
    });
  }
}

export default Home;