promise.js

  const { baseUrl } = config;
  getEndpoints(baseUrl).then(endpoints => {
    const data = new Array(endpoints.length);

    // Update the array as endpoints come in
    endpoints.map((endpoint, index) => {
      getEndpointData(endpoint, baseUrl).then(response => {
        data[index] = {endpoint, response};
        this.setState({ data });
      });
    });
  });
}