fix(patch): cherry-pick 37f128a to release/v0.27.3-pr-18478(#18743)

Co-authored-by: matt korwel <matt.korwel@gmail.com>

packages/core/src/config/models.test.ts

@@ -8,6 +8,7 @@ import { describe, it, expect } from 'vitest';
 import {
   resolveModel,
   resolveClassifierModel,
+  isGemini3Model,
   isGemini2Model,
   isAutoModel,
   getDisplayString,
@@ -25,6 +26,29 @@ import {
   DEFAULT_GEMINI_MODEL_AUTO,
 } from './models.js';
 
+describe('isGemini3Model', () => {
+  it('should return true for gemini-3 models', () => {
+    expect(isGemini3Model('gemini-3-pro-preview')).toBe(true);
+    expect(isGemini3Model('gemini-3-flash-preview')).toBe(true);
+  });
+
+  it('should return true for aliases that resolve to Gemini 3', () => {
+    expect(isGemini3Model(GEMINI_MODEL_ALIAS_AUTO, true)).toBe(true);
+    expect(isGemini3Model(GEMINI_MODEL_ALIAS_PRO, true)).toBe(true);
+    expect(isGemini3Model(PREVIEW_GEMINI_MODEL_AUTO)).toBe(true);
+  });
+
+  it('should return false for Gemini 2 models', () => {
+    expect(isGemini3Model('gemini-2.5-pro')).toBe(false);
+    expect(isGemini3Model('gemini-2.5-flash')).toBe(false);
+    expect(isGemini3Model(DEFAULT_GEMINI_MODEL_AUTO)).toBe(false);
+  });
+
+  it('should return false for arbitrary strings', () => {
+    expect(isGemini3Model('gpt-4')).toBe(false);
+  });
+});
+
 describe('getDisplayString', () => {
   it('should return Auto (Gemini 3) for preview auto model', () => {
     expect(getDisplayString(PREVIEW_GEMINI_MODEL_AUTO)).toBe('Auto (Gemini 3)');

packages/core/src/config/models.ts

@@ -137,6 +137,21 @@ export function isPreviewModel(model: string): boolean {
   );
 }
 
+/**
+ * Checks if the model is a Gemini 3 model.
+ *
+ * @param model The model name to check.
+ * @param previewFeaturesEnabled A boolean indicating if preview features are enabled.
+ * @returns True if the model is a Gemini 3 model.
+ */
+export function isGemini3Model(
+  model: string,
+  previewFeaturesEnabled: boolean = false,
+): boolean {
+  const resolved = resolveModel(model, previewFeaturesEnabled);
+  return /^gemini-3(\.|-|$)/.test(resolved);
+}
+
 /**
  * Checks if the model is a Gemini 2.x model.
  *

packages/core/src/routing/strategies/classifierStrategy.test.ts

@@ -4,19 +4,16 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { describe, it, expect, vi, beforeEach, type Mock } from 'vitest';
 import { ClassifierStrategy } from './classifierStrategy.js';
 import type { RoutingContext } from '../routingStrategy.js';
 import type { Config } from '../../config/config.js';
 import type { BaseLlmClient } from '../../core/baseLlmClient.js';
-import {
-  isFunctionCall,
-  isFunctionResponse,
-} from '../../utils/messageInspectors.js';
 import {
   DEFAULT_GEMINI_FLASH_MODEL,
   DEFAULT_GEMINI_MODEL,
   DEFAULT_GEMINI_MODEL_AUTO,
+  PREVIEW_GEMINI_MODEL_AUTO,
 } from '../../config/models.js';
 import { promptIdContext } from '../../utils/promptIdContext.js';
 import type { Content } from '@google/genai';
@@ -31,6 +28,9 @@ describe('ClassifierStrategy', () => {
   let mockConfig: Config;
   let mockBaseLlmClient: BaseLlmClient;
   let mockResolvedConfig: ResolvedModelConfig;
+  let mockGetModel: Mock;
+  let mockGetNumericalRoutingEnabled: Mock;
+  let mockGenerateJson: Mock;
 
   beforeEach(() => {
     vi.clearAllMocks();
@@ -46,23 +46,30 @@ describe('ClassifierStrategy', () => {
       model: 'classifier',
       generateContentConfig: {},
     } as unknown as ResolvedModelConfig;
+
+    mockGetModel = vi.fn().mockReturnValue(DEFAULT_GEMINI_MODEL_AUTO);
+    mockGetNumericalRoutingEnabled = vi.fn().mockResolvedValue(false);
+    mockGenerateJson = vi.fn();
+
     mockConfig = {
       modelConfigService: {
         getResolvedConfig: vi.fn().mockReturnValue(mockResolvedConfig),
       },
-      getModel: () => DEFAULT_GEMINI_MODEL_AUTO,
+      getModel: mockGetModel,
       getPreviewFeatures: () => false,
-      getNumericalRoutingEnabled: vi.fn().mockResolvedValue(false),
+      getNumericalRoutingEnabled: mockGetNumericalRoutingEnabled,
     } as unknown as Config;
+
     mockBaseLlmClient = {
-      generateJson: vi.fn(),
+      generateJson: mockGenerateJson,
     } as unknown as BaseLlmClient;
 
     vi.spyOn(promptIdContext, 'getStore').mockReturnValue('test-prompt-id');
   });
 
-  it('should return null if numerical routing is enabled', async () => {
+  it('should return null if numerical routing is enabled and model is Gemini 3', async () => {
-    vi.mocked(mockConfig.getNumericalRoutingEnabled).mockResolvedValue(true);
+    mockGetNumericalRoutingEnabled.mockResolvedValue(true);
+    mockGetModel.mockReturnValue(PREVIEW_GEMINI_MODEL_AUTO);
 
     const decision = await strategy.route(
       mockContext,
@@ -71,7 +78,25 @@ describe('ClassifierStrategy', () => {
     );
 
     expect(decision).toBeNull();
-    expect(mockBaseLlmClient.generateJson).not.toHaveBeenCalled();
+    expect(mockGenerateJson).not.toHaveBeenCalled();
+  });
+
+  it('should NOT return null if numerical routing is enabled but model is NOT Gemini 3', async () => {
+    mockGetNumericalRoutingEnabled.mockResolvedValue(true);
+    mockGetModel.mockReturnValue(DEFAULT_GEMINI_MODEL_AUTO);
+    mockGenerateJson.mockResolvedValue({
+      reasoning: 'test',
+      model_choice: 'flash',
+    });
+
+    const decision = await strategy.route(
+      mockContext,
+      mockConfig,
+      mockBaseLlmClient,
+    );
+
+    expect(decision).not.toBeNull();
+    expect(mockGenerateJson).toHaveBeenCalled();
   });
 
   it('should call generateJson with the correct parameters', async () => {
@@ -79,13 +104,11 @@ describe('ClassifierStrategy', () => {
       reasoning: 'Simple task',
       model_choice: 'flash',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
 
     await strategy.route(mockContext, mockConfig, mockBaseLlmClient);
 
-    expect(mockBaseLlmClient.generateJson).toHaveBeenCalledWith(
+    expect(mockGenerateJson).toHaveBeenCalledWith(
       expect.objectContaining({
         modelConfigKey: { model: mockResolvedConfig.model },
         promptId: 'test-prompt-id',
@@ -98,9 +121,7 @@ describe('ClassifierStrategy', () => {
       reasoning: 'This is a simple task.',
       model_choice: 'flash',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
 
     const decision = await strategy.route(
       mockContext,
@@ -108,7 +129,7 @@ describe('ClassifierStrategy', () => {
       mockBaseLlmClient,
     );
 
-    expect(mockBaseLlmClient.generateJson).toHaveBeenCalledOnce();
+    expect(mockGenerateJson).toHaveBeenCalledOnce();
     expect(decision).toEqual({
       model: DEFAULT_GEMINI_FLASH_MODEL,
       metadata: {
@@ -124,9 +145,7 @@ describe('ClassifierStrategy', () => {
       reasoning: 'This is a complex task.',
       model_choice: 'pro',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
     mockContext.request = [{ text: 'how do I build a spaceship?' }];
 
     const decision = await strategy.route(
@@ -135,7 +154,7 @@ describe('ClassifierStrategy', () => {
       mockBaseLlmClient,
     );
 
-    expect(mockBaseLlmClient.generateJson).toHaveBeenCalledOnce();
+    expect(mockGenerateJson).toHaveBeenCalledOnce();
     expect(decision).toEqual({
       model: DEFAULT_GEMINI_MODEL,
       metadata: {
@@ -151,7 +170,7 @@ describe('ClassifierStrategy', () => {
       .spyOn(debugLogger, 'warn')
       .mockImplementation(() => {});
     const testError = new Error('API Failure');
-    vi.mocked(mockBaseLlmClient.generateJson).mockRejectedValue(testError);
+    mockGenerateJson.mockRejectedValue(testError);
 
     const decision = await strategy.route(
       mockContext,
@@ -172,9 +191,7 @@ describe('ClassifierStrategy', () => {
       reasoning: 'This is a simple task.',
       // model_choice is missing, which will cause a Zod parsing error.
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(malformedApiResponse);
-      malformedApiResponse,
-    );
 
     const decision = await strategy.route(
       mockContext,
@@ -203,14 +220,11 @@ describe('ClassifierStrategy', () => {
       reasoning: 'Simple.',
       model_choice: 'flash',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
 
     await strategy.route(mockContext, mockConfig, mockBaseLlmClient);
 
-    const generateJsonCall = vi.mocked(mockBaseLlmClient.generateJson).mock
+    const generateJsonCall = mockGenerateJson.mock.calls[0][0];
-      .calls[0][0];
     const contents = generateJsonCall.contents;
 
     const expectedContents = [
@@ -239,14 +253,11 @@ describe('ClassifierStrategy', () => {
       reasoning: 'Simple.',
       model_choice: 'flash',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
 
     await strategy.route(mockContext, mockConfig, mockBaseLlmClient);
 
-    const generateJsonCall = vi.mocked(mockBaseLlmClient.generateJson).mock
+    const generateJsonCall = mockGenerateJson.mock.calls[0][0];
-      .calls[0][0];
     const contents = generateJsonCall.contents;
 
     // Manually calculate what the history should be
@@ -254,7 +265,10 @@ describe('ClassifierStrategy', () => {
     const HISTORY_TURNS_FOR_CONTEXT = 4;
     const historySlice = longHistory.slice(-HISTORY_SEARCH_WINDOW);
     const cleanHistory = historySlice.filter(
-      (content) => !isFunctionCall(content) && !isFunctionResponse(content),
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      (content: any) =>
+        !content.parts?.[0]?.functionCall &&
+        !content.parts?.[0]?.functionResponse,
     );
     const finalHistory = cleanHistory.slice(-HISTORY_TURNS_FOR_CONTEXT);
 
@@ -275,14 +289,11 @@ describe('ClassifierStrategy', () => {
       reasoning: 'Simple.',
       model_choice: 'flash',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
 
     await strategy.route(mockContext, mockConfig, mockBaseLlmClient);
 
-    const generateJsonCall = vi.mocked(mockBaseLlmClient.generateJson).mock
+    const generateJsonCall = mockGenerateJson.mock.calls[0][0];
-      .calls[0][0];
 
     expect(generateJsonCall.promptId).toMatch(
       /^classifier-router-fallback-\d+-\w+$/,
@@ -301,9 +312,7 @@ describe('ClassifierStrategy', () => {
       reasoning: 'Choice is flash',
       model_choice: 'flash',
     };
-    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+    mockGenerateJson.mockResolvedValue(mockApiResponse);
-      mockApiResponse,
-    );
 
     const contextWithRequestedModel = {
       ...mockContext,

packages/core/src/routing/strategies/classifierStrategy.ts

@@ -12,7 +12,7 @@ import type {
   RoutingDecision,
   RoutingStrategy,
 } from '../routingStrategy.js';
-import { resolveClassifierModel } from '../../config/models.js';
+import { resolveClassifierModel, isGemini3Model } from '../../config/models.js';
 import { createUserContent, Type } from '@google/genai';
 import type { Config } from '../../config/config.js';
 import {
@@ -133,7 +133,12 @@ export class ClassifierStrategy implements RoutingStrategy {
   ): Promise<RoutingDecision | null> {
     const startTime = Date.now();
     try {
-      if (await config.getNumericalRoutingEnabled()) {
+      const model = context.requestedModel ?? config.getModel();
+      const previewFeaturesEnabled = config.getPreviewFeatures();
+      if (
+        (await config.getNumericalRoutingEnabled()) &&
+        isGemini3Model(model, previewFeaturesEnabled)
+      ) {
         return null;
       }
 
@@ -164,7 +169,7 @@ export class ClassifierStrategy implements RoutingStrategy {
       const reasoning = routerResponse.reasoning;
       const latencyMs = Date.now() - startTime;
       const selectedModel = resolveClassifierModel(
-        context.requestedModel ?? config.getModel(),
+        model,
         routerResponse.model_choice,
         config.getPreviewFeatures(),
       );

packages/core/src/routing/strategies/numericalClassifierStrategy.test.ts

@@ -10,9 +10,12 @@ import type { RoutingContext } from '../routingStrategy.js';
 import type { Config } from '../../config/config.js';
 import type { BaseLlmClient } from '../../core/baseLlmClient.js';
 import {
-  DEFAULT_GEMINI_FLASH_MODEL,
+  PREVIEW_GEMINI_FLASH_MODEL,
-  DEFAULT_GEMINI_MODEL,
+  PREVIEW_GEMINI_MODEL,
   DEFAULT_GEMINI_MODEL_AUTO,
+  DEFAULT_GEMINI_MODEL,
+  PREVIEW_GEMINI_MODEL_AUTO,
+  GEMINI_MODEL_ALIAS_AUTO,
 } from '../../config/models.js';
 import { promptIdContext } from '../../utils/promptIdContext.js';
 import type { Content } from '@google/genai';
@@ -46,7 +49,7 @@ describe('NumericalClassifierStrategy', () => {
       modelConfigService: {
         getResolvedConfig: vi.fn().mockReturnValue(mockResolvedConfig),
       },
-      getModel: () => DEFAULT_GEMINI_MODEL_AUTO,
+      getModel: vi.fn().mockReturnValue(PREVIEW_GEMINI_MODEL_AUTO),
       getPreviewFeatures: () => false,
       getSessionId: vi.fn().mockReturnValue('control-group-id'), // Default to Control Group (Hash 71 >= 50)
       getNumericalRoutingEnabled: vi.fn().mockResolvedValue(true),
@@ -76,6 +79,54 @@ describe('NumericalClassifierStrategy', () => {
     expect(mockBaseLlmClient.generateJson).not.toHaveBeenCalled();
   });
 
+  it('should return null if the model is not a Gemini 3 model', async () => {
+    vi.mocked(mockConfig.getModel).mockReturnValue(DEFAULT_GEMINI_MODEL_AUTO);
+
+    const decision = await strategy.route(
+      mockContext,
+      mockConfig,
+      mockBaseLlmClient,
+    );
+
+    expect(decision).toBeNull();
+    expect(mockBaseLlmClient.generateJson).not.toHaveBeenCalled();
+  });
+
+  it('should return null if the model is explicitly a Gemini 2 model', async () => {
+    vi.mocked(mockConfig.getModel).mockReturnValue(DEFAULT_GEMINI_MODEL);
+
+    const decision = await strategy.route(
+      mockContext,
+      mockConfig,
+      mockBaseLlmClient,
+    );
+
+    expect(decision).toBeNull();
+    expect(mockBaseLlmClient.generateJson).not.toHaveBeenCalled();
+  });
+
+  it('should return a decision if model is auto and preview features are enabled (resolves to Gemini 3)', async () => {
+    vi.mocked(mockConfig.getModel).mockReturnValue(GEMINI_MODEL_ALIAS_AUTO);
+    vi.spyOn(mockConfig, 'getPreviewFeatures').mockReturnValue(true);
+
+    const mockApiResponse = {
+      complexity_reasoning: 'Simple task',
+      complexity_score: 10,
+    };
+    vi.mocked(mockBaseLlmClient.generateJson).mockResolvedValue(
+      mockApiResponse,
+    );
+
+    const decision = await strategy.route(
+      mockContext,
+      mockConfig,
+      mockBaseLlmClient,
+    );
+
+    expect(decision).not.toBeNull();
+    expect(mockBaseLlmClient.generateJson).toHaveBeenCalled();
+  });
+
   it('should call generateJson with the correct parameters and wrapped user content', async () => {
     const mockApiResponse = {
       complexity_reasoning: 'Simple task',
@@ -120,7 +171,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_FLASH_MODEL,
+        model: PREVIEW_GEMINI_FLASH_MODEL,
         metadata: {
           source: 'NumericalClassifier (Control)',
           latencyMs: expect.any(Number),
@@ -146,7 +197,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_MODEL,
+        model: PREVIEW_GEMINI_MODEL,
         metadata: {
           source: 'NumericalClassifier (Control)',
           latencyMs: expect.any(Number),
@@ -172,7 +223,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_FLASH_MODEL, // Routed to Flash because 60 < 80
+        model: PREVIEW_GEMINI_FLASH_MODEL, // Routed to Flash because 60 < 80
         metadata: {
           source: 'NumericalClassifier (Strict)',
           latencyMs: expect.any(Number),
@@ -198,7 +249,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_MODEL,
+        model: PREVIEW_GEMINI_MODEL,
         metadata: {
           source: 'NumericalClassifier (Strict)',
           latencyMs: expect.any(Number),
@@ -226,7 +277,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_FLASH_MODEL, // Score 60 < Threshold 70
+        model: PREVIEW_GEMINI_FLASH_MODEL, // Score 60 < Threshold 70
         metadata: {
           source: 'NumericalClassifier (Remote)',
           latencyMs: expect.any(Number),
@@ -252,7 +303,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_FLASH_MODEL, // Score 40 < Threshold 45.5
+        model: PREVIEW_GEMINI_FLASH_MODEL, // Score 40 < Threshold 45.5
         metadata: {
           source: 'NumericalClassifier (Remote)',
           latencyMs: expect.any(Number),
@@ -278,7 +329,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_MODEL, // Score 35 >= Threshold 30
+        model: PREVIEW_GEMINI_MODEL, // Score 35 >= Threshold 30
         metadata: {
           source: 'NumericalClassifier (Remote)',
           latencyMs: expect.any(Number),
@@ -306,7 +357,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_FLASH_MODEL, // Score 40 < Default A/B Threshold 50
+        model: PREVIEW_GEMINI_FLASH_MODEL, // Score 40 < Default A/B Threshold 50
         metadata: {
           source: 'NumericalClassifier (Control)',
           latencyMs: expect.any(Number),
@@ -333,7 +384,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_FLASH_MODEL,
+        model: PREVIEW_GEMINI_FLASH_MODEL,
         metadata: {
           source: 'NumericalClassifier (Control)',
           latencyMs: expect.any(Number),
@@ -360,7 +411,7 @@ describe('NumericalClassifierStrategy', () => {
       );
 
       expect(decision).toEqual({
-        model: DEFAULT_GEMINI_MODEL,
+        model: PREVIEW_GEMINI_MODEL,
         metadata: {
           source: 'NumericalClassifier (Control)',
           latencyMs: expect.any(Number),

packages/core/src/routing/strategies/numericalClassifierStrategy.ts

@@ -12,7 +12,7 @@ import type {
   RoutingDecision,
   RoutingStrategy,
 } from '../routingStrategy.js';
-import { resolveClassifierModel } from '../../config/models.js';
+import { resolveClassifierModel, isGemini3Model } from '../../config/models.js';
 import { createUserContent, Type } from '@google/genai';
 import type { Config } from '../../config/config.js';
 import { debugLogger } from '../../utils/debugLogger.js';
@@ -134,10 +134,16 @@ export class NumericalClassifierStrategy implements RoutingStrategy {
   ): Promise<RoutingDecision | null> {
     const startTime = Date.now();
     try {
+      const model = context.requestedModel ?? config.getModel();
+      const previewFeaturesEnabled = config.getPreviewFeatures();
       if (!(await config.getNumericalRoutingEnabled())) {
         return null;
       }
 
+      if (!isGemini3Model(model, previewFeaturesEnabled)) {
+        return null;
+      }
+
       const promptId = getPromptIdWithFallback('classifier-router');
 
       const finalHistory = context.history.slice(-HISTORY_TURNS_FOR_CONTEXT);
@@ -177,7 +183,7 @@ export class NumericalClassifierStrategy implements RoutingStrategy {
         );
 
       const selectedModel = resolveClassifierModel(
-        config.getModel(),
+        model,
         modelAlias,
         config.getPreviewFeatures(),
       );