feat: add click-to-focus support for interactive shell (#13341)

packages/cli/src/ui/hooks/useMouseClick.test.ts

@@ -0,0 +1,76 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach, type Mock } from 'vitest';
+import { renderHook } from '../../test-utils/render.js';
+import { useMouseClick } from './useMouseClick.js';
+import { getBoundingBox, type DOMElement } from 'ink';
+import type React from 'react';
+
+// Mock ink
+vi.mock('ink', async () => ({
+  getBoundingBox: vi.fn(),
+}));
+
+// Mock MouseContext
+const mockUseMouse = vi.fn();
+vi.mock('../contexts/MouseContext.js', async () => ({
+  useMouse: (cb: unknown, opts: unknown) => mockUseMouse(cb, opts),
+}));
+
+describe('useMouseClick', () => {
+  let handler: Mock;
+  let containerRef: React.RefObject<DOMElement | null>;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    handler = vi.fn();
+    containerRef = { current: {} as DOMElement };
+  });
+
+  it('should call handler with relative coordinates when click is inside bounds', () => {
+    vi.mocked(getBoundingBox).mockReturnValue({
+      x: 10,
+      y: 5,
+      width: 20,
+      height: 10,
+    } as unknown as ReturnType<typeof getBoundingBox>);
+
+    renderHook(() => useMouseClick(containerRef, handler));
+
+    // Get the callback registered with useMouse
+    expect(mockUseMouse).toHaveBeenCalled();
+    const callback = mockUseMouse.mock.calls[0][0];
+
+    // Simulate click inside: x=15 (col 16), y=7 (row 8)
+    // Terminal events are 1-based. col 16 -> mouseX 15. row 8 -> mouseY 7.
+    // relativeX = 15 - 10 = 5
+    // relativeY = 7 - 5 = 2
+    callback({ name: 'left-press', col: 16, row: 8 });
+
+    expect(handler).toHaveBeenCalledWith(
+      expect.objectContaining({ name: 'left-press' }),
+      5,
+      2,
+    );
+  });
+
+  it('should not call handler when click is outside bounds', () => {
+    vi.mocked(getBoundingBox).mockReturnValue({
+      x: 10,
+      y: 5,
+      width: 20,
+      height: 10,
+    } as unknown as ReturnType<typeof getBoundingBox>);
+
+    renderHook(() => useMouseClick(containerRef, handler));
+    const callback = mockUseMouse.mock.calls[0][0];
+
+    // Click outside: x=5 (col 6), y=7 (row 8) -> left of box
+    callback({ name: 'left-press', col: 6, row: 8 });
+    expect(handler).not.toHaveBeenCalled();
+  });
+});