feat(tools): Centralize shell tool summarization (#4009)

packages/core/src/tools/shell.test.ts

@@ -4,9 +4,11 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { expect, describe, it } from 'vitest';
+import { expect, describe, it, vi, beforeEach } from 'vitest';
 import { ShellTool } from './shell.js';
 import { Config } from '../config/config.js';
+import * as summarizer from '../utils/summarizer.js';
+import { GeminiClient } from '../core/client.js';
 
 describe('ShellTool', () => {
   it('should allow a command if no restrictions are provided', async () => {
@@ -396,3 +398,35 @@ describe('ShellTool', () => {
     );
   });
 });
+
+describe('ShellTool Bug Reproduction', () => {
+  let shellTool: ShellTool;
+  let config: Config;
+
+  beforeEach(() => {
+    config = {
+      getCoreTools: () => undefined,
+      getExcludeTools: () => undefined,
+      getDebugMode: () => false,
+      getGeminiClient: () => ({}) as GeminiClient,
+      getTargetDir: () => '.',
+    } as unknown as Config;
+    shellTool = new ShellTool(config);
+  });
+
+  it('should not let the summarizer override the return display', async () => {
+    const summarizeSpy = vi
+      .spyOn(summarizer, 'summarizeToolOutput')
+      .mockResolvedValue('summarized output');
+
+    const abortSignal = new AbortController().signal;
+    const result = await shellTool.execute(
+      { command: 'echo "hello"' },
+      abortSignal,
+    );
+
+    expect(result.returnDisplay).toBe('hello\n');
+    expect(result.llmContent).toBe('summarized output');
+    expect(summarizeSpy).toHaveBeenCalled();
+  });
+});