feat(renderer): PrintPreview overlay + App.tsx mount

tests/component/tools/PrintPreview.test.tsx

@@ -0,0 +1,49 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { PrintPreview } from '@/components/tools/PrintPreview';
+import { useFileStore } from '@/stores/file-store';
+import { useEditorStore } from '@/stores/editor-store';
+
+vi.mock('@/lib/ipc', () => ({
+  ipc: {
+    print: vi.fn().mockResolvedValue({ ok: true }),
+  },
+}));
+
+import { ipc } from '@/lib/ipc';
+
+describe('PrintPreview', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    vi.clearAllMocks();
+    useFileStore.setState({
+      activeTabId: '/test.md',
+      openTabs: [{ id: '/test.md', path: '/test.md', title: 'test.md', dirty: false }],
+    } as any);
+    useEditorStore.setState({
+      buffers: new Map([['/test.md', { id: '/test.md', path: '/test.md', content: '# hi', dirty: false }]]),
+    } as any);
+  });
+
+  it('renders the buffer content', () => {
+    render(<PrintPreview onClose={() => {}} />);
+    expect(screen.getByRole('heading', { name: /hi/i })).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: /print/i })).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: /close/i })).toBeInTheDocument();
+  });
+
+  it('Print button calls ipc.print', async () => {
+    const onClose = vi.fn();
+    render(<PrintPreview onClose={onClose} />);
+    await userEvent.click(screen.getByRole('button', { name: /print/i }));
+    expect(ipc.print).toHaveBeenCalledTimes(1);
+  });
+
+  it('Close button calls onClose', async () => {
+    const onClose = vi.fn();
+    render(<PrintPreview onClose={onClose} />);
+    await userEvent.click(screen.getByRole('button', { name: /close/i }));
+    expect(onClose).toHaveBeenCalledTimes(1);
+  });
+});