mount.js

class A extends Component {
   componentDidMount() {
    const { baseUrl } = config;
    const data = [];
    Promise.all(getEndpoints(baseUrl).then(endpoints => {
      return Promise.all(endpoints.map(endpoint => {
        return getEndpointData(endpoint, baseUrl).then(response => {
          return {endpoint, response};
        });
      }));
    })).then(data => {
      this.setState({ data });
    });
  }
}