# Git Diff Viewer Implementation ## Overview The Git Diff Viewer feature has been successfully implemented for FleetCode's web mode. This feature allows users to view changes in their session's worktree compared to the parent branch. ## Implementation Details ### 1. Dependencies - **@pierre/precision-diffs**: A powerful diff rendering library - **shiki**: Syntax highlighting for code diffs ### 2. Data Structure (types.ts) Added `FileDiff` interface to represent file changes: ```typescript export interface FileDiff { path: string; oldPath?: string; status: 'added' | 'modified' | 'deleted' | 'renamed'; diff: string; additions: number; deletions: number; } ``` ### 3. Backend (server.ts) - Added Socket.IO handler `get-session-diff` that: - Retrieves the session's worktree path and parent branch - Executes `git diff ...HEAD` using simple-git - Parses the diff output into `FileDiff` objects - Emits the parsed data back to the client via `session-diff-data` event ### 4. Frontend UI (index.html) - Added full-screen diff viewer modal with: - Header with title and close button - Left sidebar for file list - Right panel for displaying diffs - Added "Diff" button to active session items in the sidebar ### 5. Frontend Styling (styles.css) - Added comprehensive styling for: - Diff viewer modal (full-screen, responsive) - File list sidebar with status badges - Diff display area - File status indicators (added/modified/deleted/renamed) - Addition/deletion statistics - Mobile-responsive layouts ### 6. Frontend Logic (renderer.ts) - Added diff viewer functionality: - `openDiffViewer(sessionId)`: Opens modal and requests diff data - `renderDiffFileList()`: Renders list of changed files - `renderSelectedDiff()`: Renders the selected file's diff using Pierre.js - Dynamic import of libraries to avoid breaking Electron mode - Event handlers for Socket.IO events (`session-diff-data`, `session-diff-error`) ## Usage 1. Start a session and make some changes in your worktree 2. Click the "Diff" button next to an active session in the sidebar 3. A modal will appear showing all changed files 4. Click on any file to view its detailed diff 5. Click the × button or outside the modal to close ## Technical Notes - Libraries (@pierre/precision-diffs and shiki) are loaded dynamically using `import()` to avoid conflicts with Electron's module system - The diff is computed between the parent branch and HEAD of the worktree - TypeScript configuration was updated to use ES2020 modules with bundler resolution for better ESM support - The implementation is fully functional in web mode (server.ts) and does not affect Electron mode (main.ts) ## Build & Run 1. **Build the application:** ```bash npm run build:all ``` 2. **Start the server:** ```bash npm run server # or for development with hot reload: npm run dev:server ``` 3. **Access the application:** Open http://localhost:3000 in your browser ## Verification The implementation has been verified: - ✅ Dependencies installed: `@pierre/precision-diffs` and `shiki` - ✅ Server builds and runs successfully - ✅ Diff handler is present in compiled server.js - ✅ Diff libraries are bundled in renderer.web.js - ✅ All TypeScript compiles without errors