server.js

const express = require("express");
const app = express();
const { resolve } = require("path");
const bodyParser = require("body-parser");
// Replace if using a different env file or config
require("dotenv").config({ path: "./.env" });
const stripe = require("stripe")(process.env.STRIPE_SECRET_KEY);

app.use(express.static(process.env.STATIC_DIR));
// Use JSON parser for all non-webhook routes.
app.use((req, res, next) => {
  if (req.originalUrl === "/webhook") {
    next();
  } else {
    bodyParser.json()(req, res, next);
  }
});

app.get("/", (req, res) => {
  const path = resolve(process.env.STATIC_DIR + "/index.html");
  res.sendFile(path);
});

app.get("/config", async (req, res) => {
  const plan = await stripe.plans.retrieve(process.env.SUBSCRIPTION_PLAN_ID);
  res.send({
    publishableKey: process.env.STRIPE_PUBLISHABLE_KEY,
    plan
  });
});

app.post("/create-customer", async (req, res) => {
  // Create a new customer object
  const customer = await stripe.customers.create({
    name: req.body.name,
    email: req.body.email
  });

  // Create a SetupIntent to set up our payment methods recurring usage
  const setupIntent = await stripe.setupIntents.create({
    payment_method_types: ["card", "au_becs_debit"],
    customer: customer.id
  });

  res.send({ customer, setupIntent });
});

app.post("/subscription", async (req, res) => {
  // Set the default payment method on the customer
  await stripe.customers.update(req.body.customerId, {
    invoice_settings: {
      default_payment_method: req.body.paymentMethodId
    }
  });

  // Create the subscription
  const subscription = await stripe.subscriptions.create({
    customer: req.body.customerId,
    items: [{ plan: process.env.SUBSCRIPTION_PLAN_ID }],
    expand: ["latest_invoice.payment_intent"]
  });
  res.send(subscription);
});

// Webhook handler for asynchronous events.
app.post(
  "/webhook",
  bodyParser.raw({ type: "application/json" }),
  async (req, res) => {
    // Retrieve the event by verifying the signature using the raw body and secret.
    let event;

    try {
      event = stripe.webhooks.constructEvent(
        req.body,
        req.headers["stripe-signature"],
        process.env.STRIPE_WEBHOOK_SECRET
      );
    } catch (err) {
      console.log(`⚠️  Webhook signature verification failed.`);
      return res.sendStatus(400);
    }
    // Extract the object from the event.
    const dataObject = event.data.object;

    // Handle the event
    // Review important events for Billing webhooks
    // https://stripe.com/docs/billing/webhooks
    // Remove comment to see the various objects sent for this sample
    switch (event.type) {
      case "customer.created":
        console.log(`✅ Successfully created customer: ${dataObject.id}`);
        break;
      case "customer.updated":
        // console.log(dataObject);
        break;
      case "setup_intent.created":
        // console.log(dataObject);
        break;
      case "invoice.upcoming":
        // console.log(dataObject);
        break;
      case "invoice.created":
        // console.log(dataObject);
        break;
      case "invoice.finalized":
        // console.log(dataObject);
        break;
      case "invoice.payment_succeeded":
        // console.log(dataObject);
        break;
      case "invoice.payment_failed":
        // console.log(dataObject);
        break;
      case "customer.subscription.created":
        console.log(`✅ Successfully created subscription: ${dataObject.id}`);
        break;
      // ... handle other event types
      default:
      // Unexpected event type
    }
    res.sendStatus(200);
  }
);

app.listen(4242, () => console.log(`Node server listening on port ${4242}!`));