MasterResolver.js

const AWS = require("aws-sdk");
const Connect = require("aws-sdk/clients/connect");

AWS.config.setPromisesDependency(require("bluebird"));

module.exports.handler = async (event, context, callback) => {
  AWS.config.update({
    accessKeyId: "g354yh76y54hrhj",
    secretAccessKey: "dqwfwergfergerthetrhrtgrfw",
    region: "us-east-1"
  });

  const connect = new AWS.Connect();

  const params = {
    listUsers: {
      InstanceId: event.arguments.InstanceId
    }
  };

  switch (event.field) {
    case "listUsers":
      console.log("LIST USERS CASE MATCHED");
      const userList = await connect.listUsers(params.listUsers).promise();

      const userDetailList = Promise.all(
        userList.UserSummaryList.map(user => {
          return connect
            .describeUser({
              InstanceId: event.arguments.InstanceId,
              UserId: user.Id
            })
            .promise();
        })
      );

      return userDetailList
        .then(res => {
          const structuredRes = res.map(user => JSON.stringify(user.User));
          console.log(JSON.stringify(structuredRes));
          return callback(null, structuredRes);
        })
        .catch(err => callback(err, null));
      break;
    default:
      callback("Unknown field, unable to resolve" + field, null);
      break;
  }
};