feat(cli): Add setting to show status(or Gemini 's thoughts) in terminal title and taskbar icon (#4386)

Co-authored-by: Jacob Richman <jacob314@gmail.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

packages/cli/src/utils/windowTitle.test.ts

@@ -0,0 +1,59 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { computeWindowTitle } from './windowTitle.js';
+
+describe('computeWindowTitle', () => {
+  let originalEnv: NodeJS.ProcessEnv;
+
+  beforeEach(() => {
+    originalEnv = process.env;
+    vi.stubEnv('CLI_TITLE', undefined);
+  });
+
+  afterEach(() => {
+    process.env = originalEnv;
+  });
+
+  it('should use default Gemini title when CLI_TITLE is not set', () => {
+    const result = computeWindowTitle('my-project');
+    expect(result).toBe('Gemini - my-project');
+  });
+
+  it('should use CLI_TITLE environment variable when set', () => {
+    vi.stubEnv('CLI_TITLE', 'Custom Title');
+    const result = computeWindowTitle('my-project');
+    expect(result).toBe('Custom Title');
+  });
+
+  it('should remove control characters from title', () => {
+    vi.stubEnv('CLI_TITLE', 'Title\x1b[31m with \x07 control chars');
+    const result = computeWindowTitle('my-project');
+    // The \x1b[31m (ANSI escape sequence) and \x07 (bell character) should be removed
+    expect(result).toBe('Title[31m with  control chars');
+  });
+
+  it('should handle folder names with control characters', () => {
+    const result = computeWindowTitle('project\x07name');
+    expect(result).toBe('Gemini - projectname');
+  });
+
+  it('should handle empty folder name', () => {
+    const result = computeWindowTitle('');
+    expect(result).toBe('Gemini - ');
+  });
+
+  it('should handle folder names with spaces', () => {
+    const result = computeWindowTitle('my project');
+    expect(result).toBe('Gemini - my project');
+  });
+
+  it('should handle folder names with special characters', () => {
+    const result = computeWindowTitle('project-name_v1.0');
+    expect(result).toBe('Gemini - project-name_v1.0');
+  });
+});

packages/cli/src/utils/windowTitle.ts

@@ -0,0 +1,22 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Computes the window title for the Gemini CLI application.
+ *
+ * @param folderName - The name of the current folder/workspace to display in the title
+ * @returns The computed window title, either from CLI_TITLE environment variable or the default Gemini title
+ */
+export function computeWindowTitle(folderName: string): string {
+  const title = process.env['CLI_TITLE'] || `Gemini - ${folderName}`;
+
+  // Remove control characters that could cause issues in terminal titles
+  return title.replace(
+    // eslint-disable-next-line no-control-regex
+    /[\x00-\x1F\x7F]/g,
+    '',
+  );
+}