Initial import of zappier-edge from zapier monorepo

tests/meter.test.ts

@@ -0,0 +1,86 @@
+import express from 'express';
+import request from 'supertest';
+import { apiKeyAuth, Customer, InMemoryCustomerRepo } from '../src/auth';
+import { meter } from '../src/meter';
+import { DEFAULT_PRICING } from '../src/pricing';
+import { InMemoryUsageRepo } from '../src/usage';
+
+const FREE_ADA: Customer = { id: 'cust_1', name: 'Ada', tierId: 'free', apiKey: 'key-ada' };
+
+function buildApp(seed: Customer[] = [FREE_ADA]) {
+  const customers = new InMemoryCustomerRepo(seed);
+  const usage = new InMemoryUsageRepo();
+  const app = express();
+  app.use(express.json());
+  app.use(apiKeyAuth(customers));
+  app.post('/transform', meter('transform', usage, DEFAULT_PRICING), (req, res) =>
+    res.json({ quote: res.locals.quote }),
+  );
+  app.post('/storage', meter('storage', usage, DEFAULT_PRICING), (req, res) =>
+    res.json({ quote: res.locals.quote }),
+  );
+  app.post('/experimental', meter('experimental', usage, DEFAULT_PRICING), (req, res) =>
+    res.json({ quote: res.locals.quote }),
+  );
+  return { app, usage };
+}
+
+describe('meter middleware', () => {
+  it('quotes a fixed endpoint at the multiplied tier price and records usage', async () => {
+    const { app, usage } = buildApp();
+    const res = await request(app)
+      .post('/transform')
+      .set('x-api-key', 'key-ada')
+      .send({ text: 'hi' });
+    expect(res.status).toBe(200);
+    expect(res.body.quote.totalCents).toBe(4); // free tier, multiplier 1
+    const entries = usage.listFor('cust_1');
+    expect(entries).toHaveLength(1);
+    expect(entries[0].endpointId).toBe('transform');
+    expect(entries[0].cents).toBe(4);
+  });
+
+  it('charges per KB of metadata on variable endpoints', async () => {
+    const { app } = buildApp();
+    const res = await request(app)
+      .post('/storage')
+      .set('x-api-key', 'key-ada')
+      .send({ metadata: { note: 'x'.repeat(2048) } });
+    // JSON of metadata is 2059 bytes -> 3 KB -> list 10 + 3 * 1 = 13
+    expect(res.body.quote.totalCents).toBe(13);
+  });
+
+  it('applies a per-customer multiplier override', async () => {
+    const { app } = buildApp([
+      { id: 'cust_vip', name: 'Vip', tierId: 'free', apiKey: 'key-vip', multiplierOverride: 0.5 },
+    ]);
+    const res = await request(app)
+      .post('/transform')
+      .set('x-api-key', 'key-vip')
+      .send({ text: 'hi' });
+    expect(res.body.quote.totalCents).toBe(2); // list 4 x override 0.5
+  });
+
+  it('returns 401 when no customer is attached', async () => {
+    const usage = new InMemoryUsageRepo();
+    const app = express();
+    app.use(express.json());
+    app.post('/transform', meter('transform', usage, DEFAULT_PRICING), (req, res) =>
+      res.json({}),
+    );
+    const res = await request(app).post('/transform').send({ text: 'hi' });
+    expect(res.status).toBe(401);
+    expect(usage.listFor('cust_1')).toHaveLength(0);
+  });
+
+  it('returns 403 for an endpoint with no price rule on the caller tier', async () => {
+    const { app, usage } = buildApp();
+    const res = await request(app)
+      .post('/experimental')
+      .set('x-api-key', 'key-ada')
+      .send({});
+    expect(res.status).toBe(403);
+    expect(res.body.error).toMatch(/No price rule/);
+    expect(usage.listFor('cust_1')).toHaveLength(0);
+  });
+});