the previous file ResourceList.js is imported into this file/component

App.js

import React, { Component } from 'react';
import ResourceForm from './components/ResourceForm.js';
import ResourceList from './components/ResourceList.js';
import CallForPapers from './components/CallForPapers.js';


class App extends Component {
  state = {
    fields: {}
  }
  onSubmit = fields => {
    this.setState({ fields });
  };
  onChange = updatedValue => {
    this.setState({
      fields: {
        ...this.state.fields,
        ...updatedValue
      }
    });
  };

  render() {
    return (
      <div className="App">
        <ResourceForm onChange={ fields => this.onChange(fields) }/>
        <p>{ JSON.stringify(this.state.fields, null, 2) }</p>
        <ResourceList />
        <CallForPapers />
      </div>
    );
  }
}

export default App;