feat(billing): implement G1 AI credits overage flow with billing telemetry (#18590)

packages/core/src/telemetry/billingEvents.test.ts

@@ -0,0 +1,206 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { makeFakeConfig } from '../test-utils/config.js';
+import {
+  OverageMenuShownEvent,
+  OverageOptionSelectedEvent,
+  EmptyWalletMenuShownEvent,
+  CreditPurchaseClickEvent,
+  CreditsUsedEvent,
+  ApiKeyUpdatedEvent,
+  EVENT_OVERAGE_MENU_SHOWN,
+  EVENT_OVERAGE_OPTION_SELECTED,
+  EVENT_EMPTY_WALLET_MENU_SHOWN,
+  EVENT_CREDIT_PURCHASE_CLICK,
+  EVENT_CREDITS_USED,
+  EVENT_API_KEY_UPDATED,
+} from './billingEvents.js';
+
+describe('billingEvents', () => {
+  const fakeConfig = makeFakeConfig();
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date('2026-01-15T10:30:00.000Z'));
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  describe('OverageMenuShownEvent', () => {
+    it('should construct with correct properties', () => {
+      const event = new OverageMenuShownEvent(
+        'gemini-3-pro-preview',
+        500,
+        'ask',
+      );
+      expect(event['event.name']).toBe('overage_menu_shown');
+      expect(event.model).toBe('gemini-3-pro-preview');
+      expect(event.credit_balance).toBe(500);
+      expect(event.overage_strategy).toBe('ask');
+    });
+
+    it('should produce correct OpenTelemetry attributes', () => {
+      const event = new OverageMenuShownEvent(
+        'gemini-3-pro-preview',
+        500,
+        'ask',
+      );
+      const attrs = event.toOpenTelemetryAttributes(fakeConfig);
+      expect(attrs['event.name']).toBe(EVENT_OVERAGE_MENU_SHOWN);
+      expect(attrs['model']).toBe('gemini-3-pro-preview');
+      expect(attrs['credit_balance']).toBe(500);
+      expect(attrs['overage_strategy']).toBe('ask');
+    });
+
+    it('should produce a human-readable log body', () => {
+      const event = new OverageMenuShownEvent(
+        'gemini-3-pro-preview',
+        500,
+        'ask',
+      );
+      expect(event.toLogBody()).toContain('gemini-3-pro-preview');
+      expect(event.toLogBody()).toContain('500');
+    });
+  });
+
+  describe('OverageOptionSelectedEvent', () => {
+    it('should construct with correct properties', () => {
+      const event = new OverageOptionSelectedEvent(
+        'gemini-3-pro-preview',
+        'use_credits',
+        100,
+      );
+      expect(event['event.name']).toBe('overage_option_selected');
+      expect(event.selected_option).toBe('use_credits');
+      expect(event.credit_balance).toBe(100);
+    });
+
+    it('should produce correct OpenTelemetry attributes', () => {
+      const event = new OverageOptionSelectedEvent(
+        'gemini-3-pro-preview',
+        'use_fallback',
+        200,
+      );
+      const attrs = event.toOpenTelemetryAttributes(fakeConfig);
+      expect(attrs['event.name']).toBe(EVENT_OVERAGE_OPTION_SELECTED);
+      expect(attrs['selected_option']).toBe('use_fallback');
+    });
+
+    it('should produce a human-readable log body', () => {
+      const event = new OverageOptionSelectedEvent(
+        'gemini-3-pro-preview',
+        'manage',
+        100,
+      );
+      expect(event.toLogBody()).toContain('manage');
+      expect(event.toLogBody()).toContain('gemini-3-pro-preview');
+    });
+  });
+
+  describe('EmptyWalletMenuShownEvent', () => {
+    it('should construct with correct properties', () => {
+      const event = new EmptyWalletMenuShownEvent('gemini-3-pro-preview');
+      expect(event['event.name']).toBe('empty_wallet_menu_shown');
+      expect(event.model).toBe('gemini-3-pro-preview');
+    });
+
+    it('should produce correct OpenTelemetry attributes', () => {
+      const event = new EmptyWalletMenuShownEvent('gemini-3-pro-preview');
+      const attrs = event.toOpenTelemetryAttributes(fakeConfig);
+      expect(attrs['event.name']).toBe(EVENT_EMPTY_WALLET_MENU_SHOWN);
+      expect(attrs['model']).toBe('gemini-3-pro-preview');
+    });
+
+    it('should produce a human-readable log body', () => {
+      const event = new EmptyWalletMenuShownEvent('gemini-3-pro-preview');
+      expect(event.toLogBody()).toContain('gemini-3-pro-preview');
+    });
+  });
+
+  describe('CreditPurchaseClickEvent', () => {
+    it('should construct with correct properties', () => {
+      const event = new CreditPurchaseClickEvent(
+        'empty_wallet_menu',
+        'gemini-3-pro-preview',
+      );
+      expect(event['event.name']).toBe('credit_purchase_click');
+      expect(event.source).toBe('empty_wallet_menu');
+      expect(event.model).toBe('gemini-3-pro-preview');
+    });
+
+    it('should produce correct OpenTelemetry attributes', () => {
+      const event = new CreditPurchaseClickEvent(
+        'overage_menu',
+        'gemini-3-pro-preview',
+      );
+      const attrs = event.toOpenTelemetryAttributes(fakeConfig);
+      expect(attrs['event.name']).toBe(EVENT_CREDIT_PURCHASE_CLICK);
+      expect(attrs['source']).toBe('overage_menu');
+    });
+
+    it('should produce a human-readable log body', () => {
+      const event = new CreditPurchaseClickEvent(
+        'manage',
+        'gemini-3-pro-preview',
+      );
+      expect(event.toLogBody()).toContain('manage');
+      expect(event.toLogBody()).toContain('gemini-3-pro-preview');
+    });
+  });
+
+  describe('CreditsUsedEvent', () => {
+    it('should construct with correct properties', () => {
+      const event = new CreditsUsedEvent('gemini-3-pro-preview', 10, 490);
+      expect(event['event.name']).toBe('credits_used');
+      expect(event.credits_consumed).toBe(10);
+      expect(event.credits_remaining).toBe(490);
+    });
+
+    it('should produce correct OpenTelemetry attributes', () => {
+      const event = new CreditsUsedEvent('gemini-3-pro-preview', 10, 490);
+      const attrs = event.toOpenTelemetryAttributes(fakeConfig);
+      expect(attrs['event.name']).toBe(EVENT_CREDITS_USED);
+      expect(attrs['credits_consumed']).toBe(10);
+      expect(attrs['credits_remaining']).toBe(490);
+    });
+
+    it('should produce a human-readable log body', () => {
+      const event = new CreditsUsedEvent('gemini-3-pro-preview', 10, 490);
+      const body = event.toLogBody();
+      expect(body).toContain('10');
+      expect(body).toContain('490');
+      expect(body).toContain('gemini-3-pro-preview');
+    });
+  });
+
+  describe('ApiKeyUpdatedEvent', () => {
+    it('should construct with correct properties', () => {
+      const event = new ApiKeyUpdatedEvent('google_login', 'api_key');
+      expect(event['event.name']).toBe('api_key_updated');
+      expect(event.previous_auth_type).toBe('google_login');
+      expect(event.new_auth_type).toBe('api_key');
+    });
+
+    it('should produce correct OpenTelemetry attributes', () => {
+      const event = new ApiKeyUpdatedEvent('google_login', 'api_key');
+      const attrs = event.toOpenTelemetryAttributes(fakeConfig);
+      expect(attrs['event.name']).toBe(EVENT_API_KEY_UPDATED);
+      expect(attrs['previous_auth_type']).toBe('google_login');
+      expect(attrs['new_auth_type']).toBe('api_key');
+    });
+
+    it('should produce a human-readable log body', () => {
+      const event = new ApiKeyUpdatedEvent('google_login', 'api_key');
+      const body = event.toLogBody();
+      expect(body).toContain('google_login');
+      expect(body).toContain('api_key');
+    });
+  });
+});