feat(profiles): add opt-in Lean/Full and hybrid Auto selection

docker/context-profiles/complex-eval/reference3/idempotent-webhooks/src/app.js

@@ -0,0 +1,87 @@
+'use strict';
+const http = require('node:http');
+const { store } = require('./store');
+
+// Fixed after INC-104: all state checks and mutations happen synchronously in
+// one turn of the event loop — an event is claimed the instant its body is
+// parsed, before any await, so concurrent duplicates can never both pass.
+class HttpError extends Error {
+  constructor(status, code, message) {
+    super(message);
+    this.status = status;
+    this.code = code;
+  }
+}
+
+function sendJson(res, status, value) {
+  res.writeHead(status, { 'content-type': 'application/json' });
+  res.end(JSON.stringify(value));
+}
+
+function sendError(res, error) {
+  const known = error instanceof HttpError;
+  sendJson(res, known ? error.status : 500, {
+    error: { code: known ? error.code : 'INTERNAL', message: known ? error.message : 'internal error' },
+  });
+}
+
+function readBody(req) {
+  return new Promise((resolve, reject) => {
+    let body = '';
+    req.on('data', chunk => { body += chunk; });
+    req.on('end', () => {
+      try { resolve(JSON.parse(body)); } catch { reject(new HttpError(400, 'INVALID_JSON', 'body must be valid JSON')); }
+    });
+    req.on('error', reject);
+  });
+}
+
+function validateEvent(parsed) {
+  if (!parsed || typeof parsed.eventId !== 'string' || !parsed.eventId
+    || typeof parsed.orderId !== 'string' || !parsed.orderId
+    || !Number.isInteger(parsed.amountCents) || parsed.amountCents <= 0
+    || parsed.type !== 'payment.succeeded') {
+    throw new HttpError(400, 'INVALID_EVENT', 'body must be a valid payment.succeeded event');
+  }
+  return parsed;
+}
+
+// Synchronous claim-and-apply: no awaits inside, so it is atomic.
+function applyEvent({ eventId, orderId, amountCents }) {
+  if (store.processedEvents.has(eventId)) return { status: 'duplicate', orderId };
+  const order = store.orders.get(orderId);
+  if (!order) throw new HttpError(404, 'NOT_FOUND', 'no such order');
+  if (order.amountCents !== amountCents) throw new HttpError(422, 'AMOUNT_MISMATCH', 'amountCents does not match the order');
+  if (order.status === 'paid') return { status: 'already_paid', orderId };
+  store.processedEvents.add(eventId);
+  order.status = 'paid';
+  order.paidAt = new Date().toISOString();
+  order.paymentsApplied++;
+  store.paymentLog.push({ eventId, orderId, amountCents });
+  return { status: 'processed', orderId };
+}
+
+function createApp() {
+  return http.createServer(async (req, res) => {
+    const url = new URL(req.url, 'http://localhost');
+    try {
+      if (req.method === 'POST' && url.pathname === '/webhooks/payments') {
+        const parsed = validateEvent(await readBody(req));
+        sendJson(res, 200, applyEvent(parsed));
+        return;
+      }
+      const match = /^\/orders\/([\w-]+)$/.exec(url.pathname);
+      if (req.method === 'GET' && match) {
+        const order = store.orders.get(match[1]);
+        if (!order) throw new HttpError(404, 'NOT_FOUND', 'no such order');
+        sendJson(res, 200, order);
+        return;
+      }
+      throw new HttpError(404, 'NOT_FOUND', 'not found');
+    } catch (error) {
+      sendError(res, error);
+    }
+  });
+}
+
+module.exports = { createApp };