Add Integration and unit tests on Billing (#9317)

Solves [ https://github.com/twentyhq/private-issues/issues/214 ]

**TLDR**
Add unit and integration tests to Billing. First approach to run jest
integration tests directly from VSCode.

**In order to run the unit tests:**
Run unit test using the CLI or with the jest extension directly from
VSCode.

**In order to run the integration tests:**
Ensure that your database has the billingTables. If that's not the case,
migrate the database with IS_BILLING_ENABLED set to true:
` npx nx run twenty-server:test:integration
test/integration/billing/suites/billing-controller.integration-spec.ts`

**Doing:**
- Unit test on transformSubscriptionEventToSubscriptionItem
- More tests cases in billingController integration tests.

---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>
Co-authored-by: Weiko <corentin@twenty.com>
Co-authored-by: Charles Bochet <charlesBochet@users.noreply.github.com>

packages/twenty-server/test/integration/billing/suites/billing-controller.integration-spec.ts

@@ -0,0 +1,112 @@
+import request from 'supertest';
+import { createMockStripeEntitlementUpdatedData } from 'test/integration/billing/utils/create-mock-stripe-entitlement-updated-data.util';
+import { createMockStripePriceCreatedData } from 'test/integration/billing/utils/create-mock-stripe-price-created-data.util';
+import { createMockStripeProductUpdatedData } from 'test/integration/billing/utils/create-mock-stripe-product-updated-data.util';
+import { createMockStripeSubscriptionCreatedData } from 'test/integration/billing/utils/create-mock-stripe-subscription-created-data.util';
+
+const client = request(`http://localhost:${APP_PORT}`);
+
+describe('BillingController (integration)', () => {
+  it('should handle product.updated and price.created webhook events', async () => {
+    const productUpdatedPayload = {
+      type: 'product.updated',
+      data: createMockStripeProductUpdatedData(),
+    };
+    const priceCreatedPayload = {
+      type: 'price.created',
+      data: createMockStripePriceCreatedData(),
+    };
+
+    await client
+      .post('/billing/webhooks')
+      .set('Authorization', `Bearer ${ACCESS_TOKEN}`)
+      .set('stripe-signature', 'correct-signature')
+      .set('Content-Type', 'application/json')
+      .send(JSON.stringify(productUpdatedPayload))
+      .expect(200)
+      .then((res) => {
+        expect(res.body.stripeProductId).toBeDefined();
+      });
+
+    await client
+      .post('/billing/webhooks')
+      .set('Authorization', `Bearer ${ACCESS_TOKEN}`)
+      .set('stripe-signature', 'correct-signature')
+      .set('Content-Type', 'application/json')
+      .send(JSON.stringify(priceCreatedPayload))
+      .expect(200)
+      .then((res) => {
+        expect(res.body.stripePriceId).toBeDefined();
+        expect(res.body.stripeMeterId).toBeDefined();
+      });
+  });
+  it('should handle subscription.created webhook event', async () => {
+    const subscriptionCreatedPayload = {
+      type: 'customer.subscription.created',
+      data: createMockStripeSubscriptionCreatedData(),
+    };
+    const entitlementUpdatedPayload = {
+      type: 'entitlements.active_entitlement_summary.updated',
+      data: createMockStripeEntitlementUpdatedData(),
+    };
+
+    await client
+      .post('/billing/webhooks')
+      .set('Authorization', `Bearer ${ACCESS_TOKEN}`)
+      .set('stripe-signature', 'correct-signature')
+      .set('Content-Type', 'application/json')
+      .send(JSON.stringify(subscriptionCreatedPayload))
+      .expect(200)
+      .then((res) => {
+        expect(res.body.stripeSubscriptionId).toBeDefined();
+        expect(res.body.stripeCustomerId).toBeDefined();
+      });
+
+    await client
+      .post('/billing/webhooks')
+      .set('Authorization', `Bearer ${ACCESS_TOKEN}`)
+      .set('stripe-signature', 'correct-signature')
+      .set('Content-Type', 'application/json')
+      .send(JSON.stringify(entitlementUpdatedPayload))
+      .expect(200)
+      .then((res) => {
+        expect(res.body.stripeEntitlementCustomerId).toBeDefined();
+      });
+  });
+
+  it('should handle entitlements.active_entitlement_summary.updated when the subscription is not found', async () => {
+    const entitlementUpdatedPayload = {
+      type: 'entitlements.active_entitlement_summary.updated',
+      data: createMockStripeEntitlementUpdatedData({
+        customer: 'new_customer',
+      }),
+    };
+
+    await client
+      .post('/billing/webhooks')
+      .set('Authorization', `Bearer ${ACCESS_TOKEN}`)
+      .set('stripe-signature', 'correct-signature')
+      .set('Content-Type', 'application/json')
+      .send(JSON.stringify(entitlementUpdatedPayload))
+      .expect(404);
+  });
+
+  it('should reject webhook with invalid signature', async () => {
+    const entitlementUpdatedPayload = {
+      type: 'customer.entitlement.created',
+      data: {
+        object: {
+          id: 'ent_test123',
+        },
+      },
+    };
+
+    await client
+      .post('/billing/webhooks')
+      .set('Authorization', `Bearer ${ACCESS_TOKEN}`)
+      .set('stripe-signature', 'invalid-signature')
+      .set('Content-Type', 'application/json')
+      .send(JSON.stringify(entitlementUpdatedPayload))
+      .expect(500);
+  });
+});