feat: better diff. integration

tests/renderer/components/GitDiffView.test.tsx

@@ -4,6 +4,18 @@ import { render, screen } from '@testing-library/react';
 import { GitDiffView } from '../../../src/renderer/components/GitDiffView/GitDiffView';
 import { useAppStore } from '../../../src/renderer/store';
 
+vi.mock('@monaco-editor/react', () => ({
+  __esModule: true,
+  default: (_props: unknown) => null,
+  DiffEditor: (props: { original: string; modified: string; language?: string }) => (
+    <div data-testid="monaco-diff-editor">
+      <div>original:{props.original}</div>
+      <div>modified:{props.modified}</div>
+      <div>language:{props.language}</div>
+    </div>
+  ),
+}));
+
 describe('GitDiffView', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -24,9 +36,10 @@ describe('GitDiffView', () => {
       ...(window as any).electronAPI,
       git: {
         ...(window as any).electronAPI?.git,
-        getDiff: vi.fn().mockResolvedValue({
+        getDiffContent: vi.fn().mockResolvedValue({
           filePath: 'posts/first.md',
-          patch: 'diff --git a/posts/first.md b/posts/first.md\n+hello',
+          original: '# old line',
+          modified: '# new line',
         }),
       },
       app: {
@@ -36,10 +49,12 @@ describe('GitDiffView', () => {
     };
   });
 
-  it('loads and renders the git diff patch for the selected file', async () => {
+  it('loads and renders Monaco diff editor with original and modified content', async () => {
     render(<GitDiffView filePath="posts/first.md" />);
 
-    expect(await screen.findByText(/diff --git a\/posts\/first\.md b\/posts\/first\.md/i)).toBeInTheDocument();
-    expect((window as any).electronAPI.git.getDiff).toHaveBeenCalledWith('/repo/path', 'posts/first.md');
+    expect(await screen.findByTestId('monaco-diff-editor')).toBeInTheDocument();
+    expect((window as any).electronAPI.git.getDiffContent).toHaveBeenCalledWith('/repo/path', 'posts/first.md');
+    expect(screen.getByText('original:# old line')).toBeInTheDocument();
+    expect(screen.getByText('modified:# new line')).toBeInTheDocument();
   });
 });

tests/renderer/components/GitSidebar.test.tsx

@@ -34,6 +34,7 @@ describe('GitSidebar', () => {
         getRepoState: vi.fn().mockResolvedValue({ isRepo: false, hasRemote: false }),
         getStatus: vi.fn().mockResolvedValue({ files: [], counts: { untracked: 0, modified: 0, deleted: 0, renamed: 0, staged: 0, total: 0 } }),
         getDiff: vi.fn().mockResolvedValue({ filePath: 'posts/a.md', patch: 'diff --git a/posts/a.md b/posts/a.md' }),
+        getHistory: vi.fn().mockResolvedValue([]),
         init: vi.fn().mockResolvedValue({ success: true }),
         ensureGitignore: vi.fn().mockResolvedValue({ updated: false, created: false, addedEntries: [] }),
         onInitProgress: vi.fn().mockImplementation(() => () => {}),
@@ -69,6 +70,15 @@ describe('GitSidebar', () => {
       ],
       counts: { untracked: 1, modified: 1, deleted: 0, renamed: 0, staged: 0, total: 2 },
     });
+    (window as any).electronAPI.git.getHistory = vi.fn().mockResolvedValue([
+      {
+        hash: 'abc123',
+        shortHash: 'abc123',
+        date: '2026-02-16T10:00:00.000Z',
+        subject: 'feat: add git sidebar',
+        author: 'Dev One',
+      },
+    ]);
 
     render(<GitSidebar />);
 
@@ -76,6 +86,25 @@ describe('GitSidebar', () => {
     expect(screen.getByText('posts/first.md')).toBeInTheDocument();
     expect(screen.getByText('posts/second.md')).toBeInTheDocument();
     expect(screen.getByText(/version history/i)).toBeInTheDocument();
+    expect(screen.getByText(/feat: add git sidebar/i)).toBeInTheDocument();
+    expect(screen.getByText(/abc123/i)).toBeInTheDocument();
+  });
+
+  it('uses the same section-title class as posts published heading', async () => {
+    (window as any).electronAPI.git.getRepoState = vi.fn().mockResolvedValue({
+      isRepo: true,
+      rootPath: '/repo/path',
+      currentBranch: 'main',
+      hasRemote: true,
+    });
+
+    render(<GitSidebar />);
+
+    const openChangesHeader = await screen.findByText(/open changes/i);
+    const historyHeader = screen.getByText(/version history/i);
+
+    expect(openChangesHeader).toHaveClass('sidebar-section-title');
+    expect(historyHeader).toHaveClass('sidebar-section-title');
   });
 
   it('single click opens and reuses a transient git-diff tab', async () => {