Give the PR reviewer a run_tests tool

.github/workflows/review.yml

@@ -32,6 +32,8 @@ jobs:
         with:
           node-version: 22
       - run: npm ci
+      - run: npm ci
+        working-directory: apps/pr-reviewer/fixtures/demo-pr
       - name: Export the PR diff
         run: git diff origin/${{ github.base_ref }}...HEAD > fixtures/latest.diff
       - name: Run the review agent

apps/pr-reviewer/fixtures/demo-pr/cart-total.test.ts

@@ -0,0 +1,66 @@
+import { describe, expect, it } from 'vitest';
+import { cartTotal } from './cart-total.ts';
+
+describe('cartTotal', () => {
+  it('returns 0 for an empty cart', () => {
+    expect(cartTotal([])).toBe(0);
+  });
+
+  it('returns the price of a single item with quantity 1', () => {
+    expect(cartTotal([{ price: 500, qty: 1 }])).toBe(500);
+  });
+
+  it('multiplies price by quantity', () => {
+    expect(cartTotal([{ price: 250, qty: 4 }])).toBe(1000);
+  });
+
+  it('sums several items', () => {
+    expect(
+      cartTotal([
+        { price: 100, qty: 2 },
+        { price: 300, qty: 1 },
+        { price: 50, qty: 3 },
+      ]),
+    ).toBe(650);
+  });
+
+  it('counts the last item in the cart', () => {
+    expect(
+      cartTotal([
+        { price: 1, qty: 1 },
+        { price: 2, qty: 1 },
+        { price: 4, qty: 1 },
+      ]),
+    ).toBe(7);
+  });
+
+  it('ignores items with quantity 0', () => {
+    expect(
+      cartTotal([
+        { price: 999, qty: 0 },
+        { price: 10, qty: 1 },
+      ]),
+    ).toBe(10);
+  });
+
+  it('rejects a negative quantity', () => {
+    expect(() => cartTotal([{ price: 100, qty: -1 }])).toThrow(RangeError);
+  });
+
+  it('names the offending item in the negative quantity error', () => {
+    expect(() =>
+      cartTotal([
+        { price: 100, qty: 1 },
+        { price: 100, qty: -2 },
+      ]),
+    ).toThrow('Negative quantity for item 1');
+  });
+
+  it('handles zero-priced items', () => {
+    expect(cartTotal([{ price: 0, qty: 5 }])).toBe(0);
+  });
+
+  it('handles large quantities', () => {
+    expect(cartTotal([{ price: 3, qty: 1_000_000 }])).toBe(3_000_000);
+  });
+});

apps/pr-reviewer/fixtures/demo-pr/checkout-flow.integration.test.ts

@@ -0,0 +1,53 @@
+// These tests simulate the duration of the end-to-end checkout suite: each one
+// makes a real assertion and then waits 60 seconds, as a browser-driven flow would.
+import { describe, expect, it } from 'vitest';
+import { cartTotal } from './cart-total.ts';
+import { pointsFor } from './loyalty.ts';
+import { canRefund } from './refund-window.ts';
+
+const DAY_MS = 86_400_000;
+const settle = () => new Promise((r) => setTimeout(r, 60_000));
+
+describe('checkout flow', () => {
+  it('applies loyalty points across a multi-item cart', async () => {
+    const total = cartTotal([
+      { price: 2500, qty: 2 },
+      { price: 1000, qty: 1 },
+    ]);
+    expect(pointsFor(total)).toBe(90);
+    await settle();
+  });
+
+  it('refund window closes after 30 days', async () => {
+    const now = new Date('2026-10-01T12:00:00Z');
+    expect(canRefund(new Date(now.getTime() - 30 * DAY_MS), now)).toBe(true);
+    expect(canRefund(new Date(now.getTime() - 31 * DAY_MS), now)).toBe(false);
+    await settle();
+  });
+
+  it('rejects a cart with a negative quantity before awarding points', async () => {
+    expect(() => cartTotal([{ price: 1000, qty: -1 }])).toThrow(RangeError);
+    await settle();
+  });
+
+  it('awards no points for an empty cart', async () => {
+    expect(pointsFor(cartTotal([]))).toBe(0);
+    await settle();
+  });
+
+  it('keeps a delivered order refundable while points are awarded', async () => {
+    const total = cartTotal([{ price: 4000, qty: 1 }]);
+    expect(pointsFor(total)).toBe(60);
+    expect(canRefund(new Date(), new Date())).toBe(true);
+    await settle();
+  });
+
+  it('rounds loyalty points once for an odd-cent order', async () => {
+    const total = cartTotal([
+      { price: 199, qty: 1 },
+      { price: 1, qty: 1 },
+    ]);
+    expect(pointsFor(total)).toBe(3);
+    await settle();
+  });
+});

apps/pr-reviewer/fixtures/demo-pr/loyalty.test.ts

@@ -0,0 +1,44 @@
+import { describe, expect, it } from 'vitest';
+import { pointsFor } from './loyalty.ts';
+
+describe('pointsFor', () => {
+  it('awards nothing for a zero total', () => {
+    expect(pointsFor(0)).toBe(0);
+  });
+
+  it('awards 1.5 points per whole dollar', () => {
+    expect(pointsFor(10_000)).toBe(150);
+  });
+
+  it('scales linearly for large totals', () => {
+    expect(pointsFor(20_000)).toBe(300);
+  });
+
+  it('rounds half a point up', () => {
+    expect(pointsFor(100)).toBe(2);
+  });
+
+  it('rounds once, after the multiplier', () => {
+    expect(pointsFor(199)).toBe(3);
+  });
+
+  it('awards nothing below a third of a dollar', () => {
+    expect(pointsFor(33)).toBe(0);
+  });
+
+  it('rounds 0.75 points up to 1', () => {
+    expect(pointsFor(50)).toBe(1);
+  });
+
+  it('awards nothing for a single cent', () => {
+    expect(pointsFor(1)).toBe(0);
+  });
+
+  it('handles odd cent totals', () => {
+    expect(pointsFor(12_345)).toBe(185);
+  });
+
+  it('returns a whole number', () => {
+    expect(Number.isInteger(pointsFor(777))).toBe(true);
+  });
+});