How to use the firebase-admin.credential function in firebase-admin

var bodyParser = require('body-parser');
var paypal = require('paypal-rest-sdk');
var express = require('express');
var app = express();

// Initialize the app with a service account, granting admin privileges
var serviceAccount = require("path/to/serviceAccountKey.json");

paypal.configure({
  'mode': 'sandbox', //sandbox or live
  'client_id': 'REPLACE WITH PAYPAL APP CLIENT_ID',
  'client_secret': 'REPLACE WITH PAYPAL APP SECRET'
});

firebase.initializeApp({
  credential: firebase.credential.cert(serviceAccount),
  databaseURL: "https://.firebaseio.com"
});

// configure body parser
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

var port  = process.env.PORT || 5000; // set our port

// START THE SERVER
// =============================================================================
app.listen(port);
console.log('Magic happens on port ' + port);


// get an instance of the express Router

private_key_id: process.env.FBTEST_PRIVATE_KEY_ID,
		private_key: process.env.FBTEST_PRIVATE_KEY,
		client_email: process.env.FBTEST_CLIENT_EMAIL,
		client_id: process.env.FBTEST_CLIENT_ID,
		auth_uri: process.env.FBTEST_AUTH_URI,
		token_uri: process.env.FBTEST_TOKEN_URI,
		auth_provider_x509_cert_url: process.env.FBTEST_AUTH_PROVIDER_X509_CERT_URL,
		client_x509_cert_url: process.env.FBTEST_CLIENT_X509_CERT_URL
	}

	if(!serviceAccount.private_key) {
		serviceAccount = require('../tests/secret-firebase-test-server');
	}
	const key = {
		apiKey: 'AIzaSyBzVhw7ppsPkNKEahvABSl8ojMHqEd5lAg',
		credential: firebaseAdmin.credential.cert(serviceAccount),
		authDomain: 'istanbul-test.firebaseapp.com',
		databaseURL: 'https://istanbul-test.firebaseio.com/'
	}
	firebaseAdmin.initializeApp(key);
} else {
	// process.env - config vars set-up on heroku side
	let serviceAccount = {
		type: process.env.FIREBASE_TYPE,
		project_id: process.env.FIREBASE_PROJECT_ID,
		private_key_id: process.env.FIREBASE_PRIVATE_KEY_ID,
		private_key: process.env.FIREBASE_PRIVATE_KEY,
		client_email: process.env.FIREBASE_CLIENT_EMAIL,
		client_id: process.env.FIREBASE_CLIENT_ID,
		auth_uri: process.env.FIREBASE_AUTH_URI,
		token_uri: process.env.FIREBASE_TOKEN_URI,
		auth_provider_x509_cert_url: process.env.FIREBASE_AUTH_PROVIDER_X509_CERT_URL,

var app = express();
var stocks = [];

// Enable CORS
app.use(cors());

app.set('port', (process.env.PORT || 5000));
app.set('projectId', (process.env.PROJECT_ID || ''));
app.set('clientEmail', (process.env.CLIENT_EMAIL || ''));
app.set('privateKey', (process.env.PRIVATE_KEY || ''));
app.set('firebaseDB', (process.env.FIREBASE_DB || ''));

// Initialize Firebase
firebase.initializeApp({
  credential: firebase.credential.cert({
    projectId: app.get('projectId'),
    clientEmail: app.get('clientEmail'),
    privateKey: app.get('privateKey').replace(/\\n/g, '\n')
  }),
  databaseURL: app.get('firebaseDB')
});

var db = firebase.database();
var ref = db.ref('stocks');

function getRandomInt(min, max) {
  return (Math.floor(Math.random() * (max - min + 1)) + min);
}

function loadSymbols() {
  let csv = fs.readFileSync('./companies.csv', 'utf8');

module.exports = () => {
  const firebaseDBUrl = process.env.FIREBASE_DB_URL
  const serviceAccountBase64 = process.env.FIREBASE_SERVICE_ACCOUNT_BASE64

  firebase.initializeApp({
    credential: firebase.credential.cert(b64ToObject(serviceAccountBase64)),
    databaseURL: firebaseDBUrl
  })

  let database = firebase.database()

  return {
    saveTeam (id, data, done) {
      database.ref(`teams/${id}`).set(data, (err) => {
        if (err) {
          return done(err)
        }

        return done(null)
      })
    },

const getAccessToken = () => __awaiter(this, void 0, void 0, function* () {
    const accessToken = yield admin.credential
        .applicationDefault()
        .getAccessToken();
    return accessToken.access_token;
});
const getRecentTemplatesAtVersion = (accessToken, version) => __awaiter(this, void 0, void 0, function* () {

const express = require('express')
const bodyParser = require('body-parser')
const session = require('express-session')
const FileStore = require('session-file-store')(session)
const next = require('next')
const admin = require('firebase-admin')

const port = parseInt(process.env.PORT, 10) || 3000
const dev = process.env.NODE_ENV !== 'production'
const app = next({ dev })
const handle = app.getRequestHandler()

const firebase = admin.initializeApp(
  {
    credential: admin.credential.cert(require('./credentials/server')),
  },
  'server'
)

app.prepare().then(() => {
  const server = express()

  server.use(bodyParser.json())
  server.use(
    session({
      secret: 'geheimnis',
      saveUninitialized: true,
      store: new FileStore({ secret: 'geheimnis' }),
      resave: false,
      rolling: true,
      httpOnly: true,

describe('Login', function() {
  const admin = require('firebase-admin');
  const config = require('../config.json');

  admin.initializeApp({
    credential: admin.credential.cert(config.firebase.serviceAccount),
    databaseURL: config.firebase.databaseURL
  });

  const mocks = require('../../mocks');
  const UpdateUser = require('./updateUser.onCreate');

  const database = admin.database();

  const usersPath = 'quiver-functions/users';
  const usersRef = database.ref(usersPath);
  const userRef = usersRef.child(mocks.mockUser.uid);

  function cleanUp(done) {
    return Promise.all([usersRef.remove()]).then(() => done());
  }

const admin = require("firebase-admin");

const credential = process.env.FIREBASE_SVC_ACC
  ? admin.credential.cert(JSON.parse(process.env.FIREBASE_SVC_ACC))
  : admin.credential.applicationDefault();

admin.initializeApp({
  credential,
  projectId: "copenhagenjsdk",
  databaseURL: "https://copenhagenjs.firebaseio.com"
});
export { admin };

export let db = admin.firestore();

export interface FirebaseResult {
  size: number;
  docs: FirebaseResultItem[];
}

export interface FirebaseResultItem {

"use strict";

const functions = require("firebase-functions");
const admin = require("firebase-admin");
const firebase = require("firebase");
const crypto = require("crypto");
const moment = require("moment");
var serviceAccount = require("./config/serviceKey.json");
var clientAccount = require("./config/clientKey.json");
const fs = require("fs");

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: clientAccount.databaseURL,
  storageBucket: clientAccount.storageBucket
});

firebase.initializeApp(clientAccount);

const nodemailer = require("nodemailer");

const gmailEmail = functions.config().gmail.email;
const gmailPassword = functions.config().gmail.password;
const mailTransport = nodemailer.createTransport({
  service: "gmail",
  auth: {
    user: gmailEmail,
    pass: gmailPassword
  }

functions.config().sqreen.app &&
  functions.config().sqreen.app.name &&
  functions.config().sqreen.token
) {
  process.env.SQREEN_APP_NAME = functions.config().sqreen.app.name;
  process.env.SQREEN_TOKEN = functions.config().sqreen.token;

  require("sqreen");
}

const admin = require("firebase-admin");

if (process.env.NODE_ENV === "development") {
  const serviceAccount = require("../../serviceAccount.json");
  admin.initializeApp({
    credential: admin.credential.cert(serviceAccount),
    databaseURL: "https://zero-width-shortener.firebaseio.com"
  });

  debugAgent.start({
    projectId: "zero-width-shortener",
    keyFilename: "../../serviceAccount.json",
    allowExpressions: true,
    serviceContext
  });
} else {
  const profiler = require("@google-cloud/profiler");

  admin.initializeApp();

  profiler.start({
    serviceContext