File Change Follower

A VS Code extension that follows file changes in real-time, automatically opening editors and scrolling to edits as they happen. Perfect for watching CLI-based coding agents work.

Features

• Real-time file following: Automatically opens and scrolls to files as they're edited
• Change highlighting: Briefly highlights the lines that changed
• Recording & Playback: Record file change sessions and play them back later
• Timeline Panel: Visual timeline for navigating recordings
• Live Delay Mode: Buffer live events with configurable delay
• Status bar integration: See at a glance if follow mode is active, click to toggle
• Command palette: Quick access to enable, disable, or toggle follow mode
• Configurable patterns: Include or exclude files based on glob patterns
• Gitignore support: Automatically respects .gitignore patterns
• Debounced updates: Prevents overwhelming the editor during rapid changes

Use Cases

• Watching coding agents: See exactly what GitHub Copilot CLI, aider, or other AI coding assistants are doing in real-time
• Pair programming: Follow along with changes made by a colleague
• Build watching: Monitor files as they're generated by build tools
• Log tailing: Watch log files update in real-time

Installation

From VS Code Marketplace

1. Open VS Code
2. Go to Extensions (Ctrl+Shift+X)
3. Search for "File Change Follower"
4. Click Install

From VSIX

1. Download the .vsix file from Releases
2. In VS Code, open the Command Palette (Ctrl+Shift+P)
3. Run "Extensions: Install from VSIX..."
4. Select the downloaded file

Usage

Toggle Follow Mode

• Status Bar: Click the eye icon in the status bar
• Command Palette: Run "File Change Follower: Toggle Follow Mode" (Ctrl+Shift+P)

Commands

Status Bar

The status bar shows the current state:

• 👁️ Following - Follow mode is active (highlighted background)
• 👁️‍🗨️ Not Following - Follow mode is inactive

Click the status bar item to toggle the mode.

Configuration

Configure the extension in VS Code settings:

Example Settings

{
  "fileChangeFollower.enabled": false,
  "fileChangeFollower.includePatterns": ["src/**/*", "*.md"],
  "fileChangeFollower.excludePatterns": [
    "**/node_modules/**",
    "**/.git/**",
    "**/out/**"
  ],
  "fileChangeFollower.debounceMs": 150,
  "fileChangeFollower.highlightDuration": 2000,
  "fileChangeFollower.recordingsPath": ".recordings",
  "fileChangeFollower.liveDelaySeconds": 5,
  "fileChangeFollower.defaultPlaybackSpeed": 1
}

Recording & Playback

The extension supports recording file change sessions and playing them back later.

Recording

1. Run "Start Recording Session" to begin capturing file changes
2. Make changes to files in your workspace (or let a coding agent do it)
3. Run "Stop Recording and Save" to save the recording

Recordings are saved as .fcfr files (JSON Lines format) in the configured recordingsPath directory.

Playback

1. Run "Open Recording File" to load a .fcfr file
2. Run "Play Recording" to start playback
3. Use speed controls (0.25x to 4x) to adjust playback speed
4. Use skip commands to navigate between events
5. Open the Timeline Panel for visual navigation

Live Delay Mode

Live delay mode buffers incoming file changes, allowing you to watch events with a configurable delay. This is useful when you want to follow along at your own pace while an agent is actively working.

1. Set liveDelaySeconds to a value greater than 0 (e.g., 5 seconds)
2. Run "Toggle Live Delay Mode" to enable
3. Run "Catch Up to Live" to jump to real-time when needed

How It Works

When follow mode is enabled:

1. File watching: The extension monitors the workspace for file changes using VS Code's built-in file watcher
2. Text document changes: When an open document is edited, the extension captures the changed ranges
3. Debouncing: Rapid changes are debounced to prevent overwhelming the editor
4. Display: The most recently changed file is opened (without stealing focus from your terminal) and scrolled to show the changes
5. Highlighting: Changed lines are briefly highlighted using the diff editor colors

Requirements

• VS Code 1.85.0 or higher

Known Issues

• Very large files may experience slight delays when scrolling to changes
• Binary files are ignored

Contributing

Contributions are welcome! Please see the GitHub repository for more information.

License

MIT - see LICENSE for details.