feat(routing): A/B Test Numerical Complexity Scoring for Gemini 3 (#16041)

Co-authored-by: N. Taylor Mullen <ntaylormullen@google.com>

packages/core/src/code_assist/experiments/experiments.test.ts

@@ -19,6 +19,7 @@ describe('experiments', () => {
   beforeEach(() => {
     // Reset modules to clear the cached `experimentsPromise`
     vi.resetModules();
+    delete process.env['GEMINI_EXP'];
 
     // Mock the dependencies that `getExperiments` relies on
     vi.mocked(getClientMetadata).mockResolvedValue({

packages/core/src/code_assist/experiments/experiments_local.test.ts

@@ -12,12 +12,17 @@ import type { ListExperimentsResponse } from './types.js';
 import type { ClientMetadata } from '../types.js';
 
 // Mock dependencies
-vi.mock('node:fs', () => ({
-  promises: {
-    readFile: vi.fn(),
-  },
-  readFileSync: vi.fn(),
-}));
+vi.mock('node:fs', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('node:fs')>();
+  return {
+    ...actual,
+    promises: {
+      ...actual.promises,
+      readFile: vi.fn(),
+    },
+    readFileSync: vi.fn(),
+  };
+});
 vi.mock('node:os');
 vi.mock('../server.js');
 vi.mock('./client_metadata.js', () => ({

packages/core/src/code_assist/experiments/flagNames.ts

@@ -10,6 +10,8 @@ export const ExperimentFlags = {
   BANNER_TEXT_NO_CAPACITY_ISSUES: 45740199,
   BANNER_TEXT_CAPACITY_ISSUES: 45740200,
   ENABLE_PREVIEW: 45740196,
+  ENABLE_NUMERICAL_ROUTING: 45750526,
+  CLASSIFIER_THRESHOLD: 45750527,
   ENABLE_ADMIN_CONTROLS: 45752213,
 } as const;