feat(core): experimental in-progress steering hints (1 of 3) (#19008)

2026-05-03 08:24:10 -07:00 · 2026-02-17 14:59:33 -08:00
parent 5e2f5df62c
commit 55c628e967
20 changed files with 1381 additions and 60 deletions
@@ -0,0 +1,146 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi } from 'vitest';
+import type { BaseLlmClient } from '../core/baseLlmClient.js';
+import {
+  DEFAULT_FAST_ACK_MODEL_CONFIG_KEY,
+  generateFastAckText,
+  truncateFastAckInput,
+  generateSteeringAckMessage,
+} from './fastAckHelper.js';
+import { LlmRole } from 'src/telemetry/llmRole.js';
+
+describe('truncateFastAckInput', () => {
+  it('returns input as-is when below limit', () => {
+    expect(truncateFastAckInput('hello', 10)).toBe('hello');
+  });
+
+  it('truncates and appends suffix when above limit', () => {
+    const input = 'abcdefghijklmnopqrstuvwxyz';
+    const result = truncateFastAckInput(input, 20);
+    // grapheme count is 20
+    const segmenter = new Intl.Segmenter(undefined, {
+      granularity: 'grapheme',
+    });
+    expect(Array.from(segmenter.segment(result)).length).toBe(20);
+    expect(result).toContain('...[truncated]');
+  });
+
+  it('is grapheme aware', () => {
+    const input = '👨‍👩‍👧‍👦'.repeat(10); // 10 family emojis
+    const result = truncateFastAckInput(input, 5);
+    // family emoji is 1 grapheme
+    expect(result).toBe('👨‍👩‍👧‍👦👨‍👩‍👧‍👦👨‍👩‍👧‍👦👨‍👩‍👧‍👦👨‍👩‍👧‍👦');
+  });
+});
+
+describe('generateFastAckText', () => {
+  const abortSignal = new AbortController().signal;
+
+  it('uses the default fast-ack-helper model config and returns response text', async () => {
+    const llmClient = {
+      generateContent: vi.fn().mockResolvedValue({
+        candidates: [
+          { content: { parts: [{ text: '  Got it. Skipping #2.  ' }] } },
+        ],
+      }),
+    } as unknown as BaseLlmClient;
+
+    const result = await generateFastAckText(llmClient, {
+      instruction: 'Write a short acknowledgement sentence.',
+      input: 'skip #2',
+      fallbackText: 'Got it.',
+      abortSignal,
+      promptId: 'test',
+    });
+
+    expect(result).toBe('Got it. Skipping #2.');
+    expect(llmClient.generateContent).toHaveBeenCalledWith({
+      modelConfigKey: DEFAULT_FAST_ACK_MODEL_CONFIG_KEY,
+      contents: expect.any(Array),
+      abortSignal,
+      promptId: 'test',
+      maxAttempts: 1,
+      role: LlmRole.UTILITY_FAST_ACK_HELPER,
+    });
+  });
+
+  it('returns fallback text when response text is empty', async () => {
+    const llmClient = {
+      generateContent: vi.fn().mockResolvedValue({}),
+    } as unknown as BaseLlmClient;
+
+    const result = await generateFastAckText(llmClient, {
+      instruction: 'Return one sentence.',
+      input: 'cancel task 2',
+      fallbackText: 'Understood. Cancelling task 2.',
+      abortSignal,
+      promptId: 'test',
+    });
+
+    expect(result).toBe('Understood. Cancelling task 2.');
+  });
+
+  it('returns fallback text when generation throws', async () => {
+    const llmClient = {
+      generateContent: vi.fn().mockRejectedValue(new Error('boom')),
+    } as unknown as BaseLlmClient;
+
+    const result = await generateFastAckText(llmClient, {
+      instruction: 'Return one sentence.',
+      input: 'cancel task 2',
+      fallbackText: 'Understood.',
+      abortSignal,
+      promptId: 'test',
+    });
+
+    expect(result).toBe('Understood.');
+  });
+});
+
+describe('generateSteeringAckMessage', () => {
+  it('returns a shortened acknowledgement using fast-ack-helper', async () => {
+    const llmClient = {
+      generateContent: vi.fn().mockResolvedValue({
+        candidates: [
+          {
+            content: {
+              parts: [{ text: 'Got it. I will focus on the tests now.' }],
+            },
+          },
+        ],
+      }),
+    } as unknown as BaseLlmClient;
+
+    const result = await generateSteeringAckMessage(
+      llmClient,
+      'focus on tests',
+    );
+    expect(result).toBe('Got it. I will focus on the tests now.');
+  });
+
+  it('returns a fallback message if the model fails', async () => {
+    const llmClient = {
+      generateContent: vi.fn().mockRejectedValue(new Error('timeout')),
+    } as unknown as BaseLlmClient;
+
+    const result = await generateSteeringAckMessage(
+      llmClient,
+      'a very long hint that should be truncated in the fallback message if it was longer but it is not',
+    );
+    expect(result).toContain('Understood. a very long hint');
+  });
+
+  it('returns a very simple fallback if hint is empty', async () => {
+    const llmClient = {
+      generateContent: vi.fn().mockRejectedValue(new Error('error')),
+    } as unknown as BaseLlmClient;
+
+    const result = await generateSteeringAckMessage(llmClient, '   ');
+    expect(result).toBe('Understood. Adjusting the plan.');
+  });
+});