fix(credits): match the CoinPay status as a whole word, not a substring (#81)

The webhook guard tested /confirmed|completed|paid/i against the event
name, which answers "does this name contain a success word anywhere"
rather than "did the payment land". A negated status ends in one of
those words - "payment.unpaid" ends in "paid", "payment.unconfirmed"
ends in "confirmed" - so it was read as a confirmation and granted the
full credit pack for money that never arrived.

Anchor the status to the end of the event name and require a segment
separator (or the start of the string) in front of it, so the last
segment of a dotted event name has to be the status itself.

Co-authored-by: clawedassistant26 <307253840+clawedassistant26@users.noreply.github.com>

Author: clawedassistant26

apps/pwa/src/routes/credits.mjs

@@ -50,14 +50,22 @@ creditsRouter.post("/credits/buy", requireAuth, async (req, res) => {
   }
 });
 
+// The status is the last segment of a dotted event name ("payment.confirmed"),
+// so match it as a whole word. A bare substring test answers "does this name
+// contain a success word anywhere" rather than "did the payment land": a
+// negated status ends in one of them ("payment.unpaid" ends in "paid",
+// "payment.unconfirmed" ends in "confirmed") and would grant the full credit
+// pack for money that never arrived.
+const CONFIRMED_EVENT = /(?:^|[.\-_/:])(?:confirmed|completed|paid)$/i;
+
 // CoinPay confirms payment → credit the balance (idempotent on purchase id).
 creditsRouter.post("/webhooks/coinpay", async (req, res) => {
   if (config.coinpay.webhookSecret && !verifySignature(req.get("x-coinpay-signature") || req.get("webhook-signature"), req.rawBody || "", config.coinpay.webhookSecret)) {
     return res.status(401).json({ error: "bad signature" });
   }
   const event = req.body?.type || req.body?.event;
   const payId = req.body?.data?.id || req.body?.payment_id || req.body?.id;
-  if (event && /confirmed|completed|paid/i.test(event) && payId) {
+  if (event && CONFIRMED_EVENT.test(event) && payId) {
     const p = await get(`SELECT * FROM credit_purchases WHERE id = ? AND status = 'pending'`, [payId]);
     if (p) {
       // Claim the purchase atomically, the same way /cli/token claims auth

apps/pwa/test/credits-webhook-event-match.test.mjs

@@ -0,0 +1,134 @@
+// Regression tests for which CoinPay event types count as a payment
+// confirmation (POST /webhooks/coinpay).
+//
+// The guard used to be a substring test, so it answered "does this event name
+// contain a success word anywhere" rather than "is this a success event". Any
+// status that embeds one as a substring — including its own negation
+// ("payment.unpaid" contains "paid", "payment.unconfirmed" contains
+// "confirmed") — was read as a confirmation and granted the full credit pack
+// for money that never arrived.
+//
+// Same harness as credits-webhook.test.mjs: the real router against a
+// throwaway libsql file database, skipping cleanly when the PWA dependencies
+// are not installed. Run `npm install` in apps/pwa to enable them.
+import assert from "node:assert/strict";
+import http from "node:http";
+import fs from "node:fs";
+import { mkdtempSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { createRequire } from "node:module";
+import test from "node:test";
+
+const require = createRequire(import.meta.url);
+let deps = null;
+try {
+  deps = { express: require("express"), cookieParser: require("cookie-parser") };
+} catch {
+  deps = null; // pwa dependencies not installed — tests below skip
+}
+
+// Point the app at a throwaway database BEFORE importing its modules (config
+// reads the environment once, at import time).
+const workdir = mkdtempSync(path.join(tmpdir(), "moshcode-pwa-event-match-test-"));
+process.env.DATABASE_URL = `file:${path.join(workdir, "test.db")}`;
+process.env.SESSION_SECRET = "test-secret";
+
+async function boot() {
+  const { migrate } = await import("../src/migrate.mjs");
+  await migrate();
+  const { run, all } = await import("../src/db.mjs");
+  const { sessionMiddleware, csrfGuard } = await import("../src/lib/session.mjs");
+  const { creditsRouter } = await import("../src/routes/credits.mjs");
+
+  const app = deps.express();
+  app.use(deps.express.json({ verify: (req, _res, buf) => { req.rawBody = buf.toString("utf8"); } }));
+  app.use(deps.express.urlencoded({ extended: false }));
+  app.use(deps.cookieParser());
+  app.use(sessionMiddleware);
+  app.use(csrfGuard);
+  app.use(creditsRouter);
+  const server = await new Promise((resolve) => {
+    const s = app.listen(0, "127.0.0.1", () => resolve(s));
+  });
+  const { port } = server.address();
+
+  const seedPurchase = async (payId, { userId = "u1", credits = 1000, usd = 5 } = {}) => {
+    await run(`INSERT OR REPLACE INTO users (id, email, display_name, created_at) VALUES (?,?,?,1)`,
+      [userId, `${userId}@b.c`, "demo"]);
+    await run(
+      `INSERT INTO credit_purchases (id,user_id,credits,amount_usd,status,created_at) VALUES (?,?,?,?,?,?)`,
+      [payId, userId, credits, usd, "pending", Date.now()]
+    );
+  };
+
+  const granted = async (userId) => {
+    const rows = await all(
+      `SELECT delta FROM credit_ledger WHERE user_id = ? AND reason = 'topup.coinpay'`, [userId]);
+    return { rows: rows.length, total: rows.reduce((s, r) => s + Number(r.delta), 0) };
+  };
+
+  const deliver = (payId, type) => new Promise((resolve, reject) => {
+    const req = http.request({
+      host: "127.0.0.1", port, path: "/webhooks/coinpay", method: "POST", agent: false,
+      headers: { "content-type": "application/json" },
+    }, (res) => {
+      let data = "";
+      res.on("data", (chunk) => { data += chunk; });
+      res.on("end", () => resolve({ status: res.statusCode, body: JSON.parse(data) }));
+    });
+    req.on("error", reject);
+    req.end(JSON.stringify({ type, data: { id: payId } }));
+  });
+
+  return { all, server, seedPurchase, granted, deliver };
+}
+
+let booted = null;
+const app = () => (booted ||= boot());
+
+test.after(() => {
+  if (!booted) return;
+  booted.then(({ server }) => server.close())
+    .finally(() => { try { fs.rmSync(workdir, { recursive: true, force: true }); } catch { /* noop */ } });
+});
+
+// A status that negates a success word must not be read as a confirmation.
+// "unpaid" ends in "paid" and "unconfirmed" ends in "confirmed", so a
+// substring test grants the pack for a payment that did not land.
+for (const type of ["payment.unpaid", "payment.unconfirmed"]) {
+  test(`webhooks/coinpay: "${type}" credits nothing`, { skip: !deps && "apps/pwa deps not installed" }, async () => {
+    const { seedPurchase, granted, deliver, all } = await app();
+    const payId = `pay-${type.replace(/\W/g, "-")}`;
+    const userId = `u-${type.replace(/\W/g, "-")}`;
+
+    await seedPurchase(payId, { userId });
+    const res = await deliver(payId, type);
+    assert.equal(res.status, 200);
+
+    assert.deepEqual(await granted(userId), { rows: 0, total: 0 },
+      `${type} must not grant credits`);
+    const [p] = await all(`SELECT status FROM credit_purchases WHERE id = '${payId}'`);
+    assert.equal(p.status, "pending", `${type} must leave the purchase pending`);
+  });
+}
+
+// Controls: the confirmation paths the app actually depends on must keep
+// working. These pass both before and after the fix — they prove the fix
+// tightened the guard rather than disabling the webhook.
+for (const type of ["payment.confirmed", "payment.completed", "payment.paid", "PAYMENT.CONFIRMED"]) {
+  test(`webhooks/coinpay: "${type}" still credits the balance`, { skip: !deps && "apps/pwa deps not installed" }, async () => {
+    const { seedPurchase, granted, deliver, all } = await app();
+    const payId = `pay-ok-${type.replace(/\W/g, "-")}`;
+    const userId = `u-ok-${type.replace(/\W/g, "-")}`;
+
+    await seedPurchase(payId, { userId });
+    const res = await deliver(payId, type);
+    assert.equal(res.status, 200);
+
+    assert.deepEqual(await granted(userId), { rows: 1, total: 1000 },
+      `${type} must grant the pack exactly once`);
+    const [p] = await all(`SELECT status FROM credit_purchases WHERE id = '${payId}'`);
+    assert.equal(p.status, "cleared");
+  });
+}