Module Viz - D Dependency Visualizer

A simple tool that helps you understand and visualize how modules in your D projects depend on each other.

This is an example of a dependency graph of that example project generated by Module Viz.

I also tried this in the phobos codebase, the graph looks like this. Yes, this is huge😅 -

What does it do?

Module Viz scans your D project, figures out how your modules are connected through imports, and creates visual diagrams that help you understand your codebase structure.

Key features:

• ✅ Creates visual dependency graphs from your D code
• ✅ Shows how modules connect to each other
• ✅ Generates both graphical and text-based visualizations
• ✅ Color-codes modules based on their role in your project
• ✅ Works on Windows, Linux, and macOS

Getting Started

Option 1: Download the pre-built executable (recommended)

1. Download the tool

   • Go to the Releases page
   • Download the zip file for your platform (e.g., module-viz-v1.0.0-win-x64.zip for Windows)

2. Install it

   • Extract the zip file to a folder of your choice
   • For convenience, you might want to place viz.exe in a dedicated folder like C:\Tools\ModuleViz or ~/tools/moduleviz

3. Add to your PATH (optional but recommended)

   On Windows:

   • Right-click on "This PC" or "My Computer" and select "Properties"
   • Click on "Advanced system settings"
   • Click on the "Environment Variables" button
   • Under "System variables" (or "User variables" for just your account), find the "Path" variable and click "Edit"
   • Click "New" and add the folder path where you placed viz.exe (e.g., C:\Tools\ModuleViz)
   • Click "OK" on all dialog boxes
   • Restart any open command prompts for the change to take effect

   On Linux/macOS:

   • Edit your ~/.bashrc, ~/.zshrc, or equivalent shell configuration file
   • Add this line: export PATH="$PATH:/path/to/folder/containing/viz"
   • Save the file and run source ~/.bashrc (or appropriate file) or restart your terminal

Option 2: Build from source

If you prefer to build the tool yourself:

1. Prerequisites

   • D compiler (DMD, LDC, or GDC)
   • DUB package manager

2. Build steps

   # Clone the repository
   git clone https://github.com/abulgit/module-viz.git
   cd module-viz
   
   # Build the project
   dub build
   
   # The executable will be in the bin directory

How to Use

Basic Usage

# If added to PATH:
viz --input=path/to/project

# If not added to PATH (Windows):
C:\path\to\viz.exe --input=path/to/project

# If not added to PATH (Linux/macOS):
/path/to/viz --input=path/to/project

Common Commands

Create a dependency graph of your project:

viz --input=path/to/project --output=graph.dot --image

See a text-based graph:

viz --input=path/to/project --text

Get help:

viz --help

All Available Options

--input=PATH, -i       Directory containing D source files to analyze (default: current directory)
--output=FILE, -o      Output .dot file (default: dependency_graph.dot)
--image, --img         Automatically generate image from the dot file
--format=FORMAT, -f    Image format (png, svg, pdf, etc.) when using --image (default: png)
--text, -t             Display text-based visualization of the dependency graph
--help, -h             Show help information

Understanding the Visualization

Color Meaning

The tool color-codes modules to help you understand their role:

• Light Green: Base modules that are only imported by other modules but don't import anything
• Salmon: Entry point modules that import other modules but aren't imported by anything
• Gold: Hub modules that are heavily connected (both importing and being imported)
• Light Blue: Regular modules with balanced dependencies

Image Generation Requirements

To generate images, you need GraphViz installed on your system.

If you don't have GraphViz or can't install it, you can:

1. Use the --text option to see a text representation
2. Upload the .dot file to an online GraphViz tool:
   • GraphvizOnline
   • Edotor
   • Sketchviz

Examples

Analyzing a D Project

# Generate a PNG visualization of a project
viz --input=path/to/dproject --image

# Generate an SVG instead of PNG
viz --input=path/to/dproject --image --format=svg

# Show both text and graphical visualization
viz --input=path/to/dproject --text --image

Demo Project

The repository includes an example project in the example/ directory:

# Analyze the example project
viz --input=example --output=example.dot --image --text

Troubleshooting

Common Issues

• "Command not found": Make sure viz is in your PATH or use the full path to the executable
• Image generation fails: Install GraphViz from https://graphviz.org/download/
• No modules found: Check that you're pointing to a directory with .d files

Need Help?

If you encounter any issues, please open an issue on GitHub.

License

Proprietary

Dependencies

• libdparse - D language parsing library