Handle Stripe charge with source using express.js

index.js

const STRIPE_SECRET = 'STRIPE_SECRET';

// const keyPublishable = 'pk_test_19ahJzPH2xE2Dd9zhqv6R6fR';
const STRIPE_SECRET = 'sk_test_ZqMsK6wX4raLqGcICamzZiP9';

const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const stripe = require('stripe')(STRIPE_SECRET);

const app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(express.static(path.join(__dirname, 'www')));
app.use((req, res, next) => {
  res.setHeader('Access-Control-Allow-Origin', 'http://localhost:8000');
  res.setHeader('Access-Control-Allow-Methods', 'POST');
  res.setHeader(
    'Access-Control-Allow-Headers',
    'X-Requested-With,content-type',
  );
  next();
});

const makeCharge = (res, sourceId, amount, currency) =>
  stripe.charges.create(
    {
      amount,
      currency,
      source: sourceId,
    },
    (err, charge) => {
      if (err !== null) {
        res.status(500).send({ error: 'Purchase Failed. Please try again.' });
      } else {
        res.send(charge);
      }
    },
  );

const retrieveSource = (sourceId, callback) =>
  stripe.sources.retrieve(sourceId, (err, source) => callback(source));

app.post('/charge', (req, res) => {
  const { sourceId } = req.body;
  retrieveSource(sourceId, ({ amount, currency }) => {
    makeCharge(res, sourceId, amount, currency);
  });
});

app.listen(3000, (req, res) => {
  console.log(
    'Server is running. Point your browser to: http://localhost:3000',
  );
});