restate-stripe-poc.ts

import * as restate from "@restatedev/restate-sdk";
import { serde } from "@restatedev/restate-sdk-zod";
import { Stripe } from 'stripe';

const stripe = new Stripe('STRIPE_KEY');

const apiHandler = restate.service({
  name: "APIHandler",
  handlers: {
    async onStripeEvent(ctx, event: Stripe.Event) {
      if (event.type === 'checkout.session.completed') {
        const purchaseId = event.data.object.client_reference_id;
        if (!purchaseId) return;

        ctx.workflowSendClient(purchaseWorkflow, purchaseId).onPaymentSucceeded();
      } else if (event.type === 'checkout.session.expired') {
        const purchaseId = event.data.object.client_reference_id;
        if (!purchaseId) return;

        ctx.workflowSendClient(purchaseWorkflow, purchaseId).onPaymentExpired();
      }
    },
    async createCheckoutSession(ctx) {
      const purchaseId = ctx.rand.uuidv4();

      const stripeCheckoutSession = await ctx.run('Checkout Session 作成', () => {
        return stripe.checkout.sessions.create({
          line_items: [{
            quantity: 1,
            price_data: {
              currency: 'JPY',
              unit_amount: 100,
              product_data: {
                name: '商品',
              },
            },
          }],
          success_url: 'http://example.com',
          mode: 'payment',
          client_reference_id: purchaseId,
        });
      });

      ctx.workflowClient(purchaseWorkflow, purchaseId).run();

      return stripeCheckoutSession.url;
    },
  },
});

const purchaseWorkflow = restate.workflow({
  name: 'Purchase',
  handlers: {
    async run(ctx) {
      console.log('商品確保');

      const paymentSucceeded = await ctx.promise<boolean>('paymentSucceeded');
      if (!paymentSucceeded) {
        console.log('商品解放');
        return;
      }
      console.log('商品購入完了');

      await ctx.run(() => {
        console.log('メール送信');
      });
    },

    async onPaymentSucceeded(ctx: restate.WorkflowSharedContext) {
      await ctx.promise<boolean>('paymentSucceeded').resolve(true);
    },

    async onPaymentExpired(ctx: restate.WorkflowSharedContext) {
      await ctx.promise<boolean>('paymentSucceeded').resolve(false);
    },
  },
});

restate.serve({
  services: [apiHandler, purchaseWorkflow],
  port: 9080,
});