npm run import -- "zuora account service"

var zuoraExport = importer.import("zuora export service");
var request = importer.import("request polyfill");

module.exports = {
    getZuoraAccounts,
    zuoraQuery
};

function zuoraQuery(query, zuoraConfig) {
    return request.request({
        followAllRedirects: true,
        uri: zuoraConfig.rest_api_url + '/action/query',
        json: {
            queryString: query
        },
        method: 'POST',
        headers: zuoraExport.getAuthHeaders(zuoraConfig)
    });
}

function getContact(email, zuoraConfig) {
    return module.exports.zuoraQuery(`
SELECT AccountId, PersonalEmail, WorkEmail
FROM Contact
WHERE PersonalEmail LIKE '${email}'
OR WorkEmail LIKE '${email}'`, zuoraConfig)
}

function getAccountById(accountId, zuoraConfig) {
    return module.exports.zuoraQuery(`
SELECT Id, Status, Name, Currency, DefaultPaymentMethodId
FROM Account
WHERE Id='${accountId}'`, zuoraConfig);
}

function getPaymentMethod(paymentId, zuoraConfig) {
    return module.exports.zuoraQuery(`
SELECT CreditCardMaskNumber
FROM PaymentMethod
WHERE Id='${paymentId}'`, zuoraConfig);
}

function getAccountLast4Digits(email, zuoraConfig) {
    return getContact(email, zuoraConfig)
        .then(r => getAccountById(r.body.records[0].AccountId, zuoraConfig))
        .then(r => getPaymentMethod(r.body.records[0].DefaultPaymentMethodId, zuoraConfig))
        .then(r => {
            return {
                "EmailAddress": email,
                "Last4DigitsOfCard": r.body.records[0].CreditCardMaskNumber
            }
        })
}

function getZuoraAccounts(notifyRequest, zuoraConfig) {
    if(!notifyRequest.items) {
        return Promise.resolve([]).then(() => {
            throw new Error('Account items not defined, nothing to do!');
        });
    }
    return Promise.all(notifyRequest.items.map(c => {
        return getAccountLast4Digits(c.EmailAddress, zuoraConfig);
    }))
}

What the code could have been:

const { promisify } = require('util');
const request = promisify(require('request-polyfill'));
const ZuoraExportService = require('./zuora-export-service');

module.exports = {
  getZuoraAccounts,
  zuoraQuery
};

class ZuoraQuery {
  constructor(zuoraConfig) {
    this.zuoraConfig = zuoraConfig;
  }

  query(query) {
    const authHeaders = ZuoraExportService.getAuthHeaders(this.zuoraConfig);
    const options = {
      followAllRedirects: true,
      uri: this.zuoraConfig.rest_api_url + '/action/query',
      json: {
        queryString: query
      },
      method: 'POST',
      headers: authHeaders
    };

    return request(options);
  }
}

class ContactService {
  constructor(zuoraQuery, zuoraConfig) {
    this.zuoraQuery = zuoraQuery;
    this.zuoraConfig = zuoraConfig;
  }

  async getContact(email) {
    const query = `
      SELECT AccountId, PersonalEmail, WorkEmail
      FROM Contact
      WHERE PersonalEmail LIKE '${email}'
      OR WorkEmail LIKE '${email}'
    `;
    const response = await this.zuoraQuery.query(query);
    return response.body;
  }
}

class AccountService {
  constructor(zuoraQuery, zuoraConfig) {
    this.zuoraQuery = zuoraQuery;
    this.zuoraConfig = zuoraConfig;
  }

  async getAccountById(accountId) {
    const query = `
      SELECT Id, Status, Name, Currency, DefaultPaymentMethodId
      FROM Account
      WHERE Id='${accountId}'
    `;
    const response = await this.zuoraQuery.query(query);
    return response.body;
  }
}

class PaymentMethodService {
  constructor(zuoraQuery, zuoraConfig) {
    this.zuoraQuery = zuoraQuery;
    this.zuoraConfig = zuoraConfig;
  }

  async getPaymentMethod(paymentId) {
    const query = `
      SELECT CreditCardMaskNumber
      FROM PaymentMethod
      WHERE Id='${paymentId}'
    `;
    const response = await this.zuoraQuery.query(query);
    return response.body;
  }
}

class AccountLast4DigitsService {
  constructor(contactService, accountService, paymentMethodService, zuoraConfig) {
    this.contactService = contactService;
    this.accountService = accountService;
    this.paymentMethodService = paymentMethodService;
    this.zuoraConfig = zuoraConfig;
  }

  async getAccountLast4Digits(email) {
    const contactResponse = await this.contactService.getContact(email);
    const accountId = contactResponse.records[0].AccountId;
    const accountResponse = await this.accountService.getAccountById(accountId);
    const paymentMethodId = accountResponse.records[0].DefaultPaymentMethodId;
    const paymentMethodResponse = await this.paymentMethodService.getPaymentMethod(paymentMethodId);

    return {
      EmailAddress: email,
      Last4DigitsOfCard: paymentMethodResponse.records[0].CreditCardMaskNumber
    };
  }
}

class ZuoraAccountsService {
  constructor(zuoraQuery, zuoraConfig) {
    this.zuoraQuery = zuoraQuery;
    this.zuoraConfig = zuoraConfig;
  }

  async getZuoraAccounts(notifyRequest) {
    if (!notifyRequest.items) {
      throw new Error('Account items not defined, nothing to do!');
    }
    const services = notifyRequest.items.map(c => this.getAccountLast4DigitsService(c.EmailAddress));
    return Promise.all(services);
  }

  getAccountLast4DigitsService(email) {
    return new AccountLast4DigitsService(
      new ContactService(this.zuoraQuery, this.zuoraConfig),
      new AccountService(this.zuoraQuery, this.zuoraConfig),
      new PaymentMethodService(this.zuoraQuery, this.zuoraConfig),
      this.zuoraConfig
    );
  }
}

function getZuoraAccounts(notifyRequest, zuoraConfig) {
  return new ZuoraAccountsService(new ZuoraQuery(zuoraConfig), zuoraConfig).getZuoraAccounts(notifyRequest);
}

function zuoraQuery(query, zuoraConfig) {
  return new ZuoraQuery(zuoraConfig).query(query);
}