feat: version diffs work now

tests/renderer/components/TabBar.test.tsx

@@ -0,0 +1,81 @@
+import React from 'react';
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import { TabBar } from '../../../src/renderer/components/TabBar/TabBar';
+import { useAppStore } from '../../../src/renderer/store';
+
+describe('TabBar', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+
+    (window as any).addEventListener = vi.fn();
+    (window as any).removeEventListener = vi.fn();
+
+    if (!(globalThis as any).ResizeObserver) {
+      (globalThis as any).ResizeObserver = class {
+        observe() {}
+        disconnect() {}
+      };
+    }
+
+    useAppStore.setState({
+      activeProject: {
+        id: 'project-1',
+        name: 'Test Project',
+        slug: 'test-project',
+        isActive: true,
+        dataPath: '/repo/path',
+        createdAt: new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+      },
+      tabs: [
+        { type: 'git-diff', id: 'git-diff:commit:abc123def456', isTransient: false },
+      ],
+      activeTabId: 'git-diff:commit:abc123def456',
+      media: [],
+      dirtyPosts: new Set<string>(),
+      sidebarVisible: true,
+    });
+
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      git: {
+        ...(window as any).electronAPI?.git,
+        getHistory: vi.fn().mockResolvedValue([
+          {
+            hash: 'abc123def456',
+            shortHash: 'abc123d',
+            date: '2026-02-16T10:00:00.000Z',
+            subject: 'feat: improve commit diff tabs',
+            author: 'Dev One',
+          },
+        ]),
+      },
+      app: {
+        ...(window as any).electronAPI?.app,
+        getDefaultProjectPath: vi.fn().mockResolvedValue('/repo/path'),
+      },
+      posts: {
+        ...(window as any).electronAPI?.posts,
+        get: vi.fn(),
+      },
+      chat: {
+        ...(window as any).electronAPI?.chat,
+        getConversation: vi.fn(),
+        onTitleUpdated: vi.fn(() => () => {}),
+      },
+      importDefinitions: {
+        ...(window as any).electronAPI?.importDefinitions,
+        get: vi.fn(),
+        onNameUpdated: vi.fn(() => () => {}),
+      },
+    };
+  });
+
+  it('renders commit subject in git-diff commit tab titles when available', async () => {
+    render(<TabBar />);
+
+    expect(await screen.findByText('abc123d feat: improve commit diff tabs')).toBeInTheDocument();
+    expect((window as any).electronAPI.git.getHistory).toHaveBeenCalledWith('/repo/path', 200);
+  });
+});