TypeScript for connecting to AWS Neptune w/ v4 Signature

getGremlinClient.ts

import { driver, structure, process as gremlinProcess } from 'gremlin';
import { fromNodeProviderChain } from '@aws-sdk/credential-providers';
import { getUrlAndHeaders } from 'gremlin-aws-sigv4/lib/utils';

async function getCredentials() {
  try {
    const provider = fromNodeProviderChain({
      clientConfig: { region: process.env.REGION },
    });
    const credentials = await provider();
    return { ...credentials, region: process.env.REGION };
  } catch (e) {
    console.error('No credentials found', e);
    throw e; 
  }
}

export const getGremlinClient = async (
  neptuneUrl: string,
): Promise<gremlinProcess.GraphTraversalSource> => {
  const credentials = await getCredentials();
  const { url, headers } = getUrlAndHeaders(
    neptuneUrl,
    '8182',
    credentials,
    '/gremlin',
    'wss',
  );

  const dc = new driver.DriverRemoteConnection(url, { headers });
  const graph = new structure.Graph();
  return graph.traversal().withRemote(dc);
};