shafu-rs - Rust Solidity Formatter

A fast Solidity code formatter written in Rust that applies the "shafu" style formatting rules.

Features

• Variable declarations: Aligns type declarations with proper spacing
• Function declarations: Converts single-line functions with >2 parameters to multiline format
• Import statements: Aligns import statements with proper spacing
• Require statements: Aligns require conditions and error messages in tabular format
• Constructor declarations: Formats constructors with aligned parameters
• Variable assignments: Aligns assignment operators and handles storage/memory modifiers
• Struct assignments: Aligns struct field assignments with colons
• Double space before braces: Adds double space before opening braces
• uint256 → uint conversion: Converts uint256 to shorter uint syntax

Installation

Prerequisites

• Rust (1.70 or later)
• forge (Foundry)

Build from source

# Clone and build
git clone <repository>
cd shafu-rs
cargo build --release

# The binary will be available at target/release/shafu

Install globally

cargo install --path .

Usage

Command Line Interface

# Format a file and print to stdout
shafu path/to/your/file.sol

# Format a file and write changes back
shafu path/to/your/file.sol --write

Examples

Before formatting:

contract Example {
    uint256 public balance;
    address public owner;
    
    function transfer(address to, uint256 amount, bytes memory data) external {
        require(balance >= amount, "Insufficient balance");
        require(to != address(0), "Invalid address");
    }
}

After formatting:

contract Example {
    uint    public balance;
    address public owner;
    
    function transfer(
        address to,
        uint    amount,
        bytes   memory data
    )
        external
    {
        require(balance >= amount, "Insufficient balance");
        require(to      != address(0), "Invalid address");
    }
}

Development

Project Structure

shafu-rs/
├── src/
│   ├── main.rs          # CLI interface
│   ├── lib.rs           # Main library entry point
│   └── formatter.rs     # Core formatting logic
├── Cargo.toml
└── README.md

Testing

# Run tests
cargo test

# Test against example files
cargo run -- ../shafu-formatter/tests/0_before/00_simple_storage_vars.sol

Building

# Debug build
cargo build

# Release build  
cargo build --release

# Run directly
cargo run -- <file.sol> [--write]

Differences from Python Version

The Rust version maintains functional parity with the Python version while offering:

• Performance: Significantly faster execution
• Memory safety: No runtime panics from memory errors
• Type safety: Compile-time guarantees about data handling
• Single binary: No external dependencies at runtime (except forge)

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new functionality
5. Submit a pull request

License

[License information here]