Sniffer

Overview

Sniffer is a debug adapter for Minecraft datapacks that allows you to debug your .mcfunction files directly from Visual Studio Code. It provides features like breakpoints, step execution, and variable inspection to make datapack development easier and more efficient.

Features

• Set breakpoints in .mcfunction files
• Connect to a running Minecraft instance
• Inspect game state during debugging
• Step through command execution
• Path mapping between Minecraft and local files

Requirements

• Minecraft with Fabric Loader
• Visual Studio Code

Mod Configuration

The mod can be configured through the in-game configuration screen, accessible via Mod Menu. You can also configure the mod in the config/sniffer.json file. The following options are available:

Debug Server Settings

• Server Port: The port number for the debug server (default: 25599)
• Server path: The path to the debug server (default: /dap)

Connecting to Minecraft

1. Open your datapack project in VSCode
2. Create a .vscode/launch.json file with the following configuration:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "sniffer",
      "request": "attach",
      "name": "Connect to Minecraft",
      "address": "ws://localhost:25599/dap"
    }
  ]
}

3. Start Minecraft with the Sniffer mod installed
4. In VSCode, press F5 or click the "Run and Debug" button
5. Select "Connect to Minecraft" from the dropdown menu

You can now place breakpoints in your .mcfunction files and execute it from the game to step through the code.

Usage in Minecraft

The debugger can be controlled directly from Minecraft using the following commands:

• /breakpoint continue: Resume execution after hitting a breakpoint
• /breakpoint step: Execute the next command and pause
• /breakpoint step_over: Skip to the next command in the current function
• /breakpoint step_out: Continue execution until the current function returns

All commands require operator permissions (level 2) to use.

When execution is paused at a breakpoint, the gametick will be freezed.

Development

Project Structure

• src/main: Main mod code for Minecraft
• src/client: Client-side mod code
• vscode: VSCode extension source code

Building the Project

To build the Minecraft mod:

./gradlew build

To build the VSCode extension:

cd vscode
npm install
npm run build

License

This project is licensed under the MPL-2.0 License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Acknowledgements

• Fabric - Mod loader for Minecraft
• VSCode Debug Adapter - VSCode debugging API
• Datapack Debugger by Alumopper - Original implementation of the debugger, without the DAP layer