🚀 Solidity Gas Optimizer

A powerful CLI tool that analyzes Solidity smart contracts to detect gas optimization opportunities. Save thousands in gas fees by identifying and fixing common inefficient patterns.

✨ Features

• 🔍 Storage Read in Loops - Detect expensive storage reads inside loops
• 🔐 Public vs External - Identify functions that should be external instead of public
• 📦 State Variable Packing - Find inefficient variable ordering that wastes storage slots
• 🚨 Custom Errors - Suggest replacing string reverts with gas-efficient custom errors
• 🎨 Beautiful Output - Color-coded results with detailed suggestions
• ⚡ Fast Analysis - Powered by AST parsing for accurate detection

📊 Real Impact

// Before optimization: 103,320 gas
contract Unoptimized {
    uint128 a;      // slot 0 (wasted 128 bits)
    uint256 b;      // slot 1
    uint128 c;      // slot 2 (wasted 128 bits)
    
    function sum() public view returns (uint256) {
        uint256 total = 0;
        for (uint i = 0; i < array.length; i++) {  // 100 gas per iteration
            total += array[i];
        }
        return total;
    }
}

// After optimization: 23,420 gas (77% savings!)
contract Optimized {
    uint256 b;      // slot 0
    uint128 a;      // slot 1
    uint128 c;      // slot 1 (packed!)
    
    function sum() external view returns (uint256) {
        uint256 total = 0;
        uint256 length = array.length;  // Cache length
        for (uint i = 0; i < length; i++) {
            total += array[i];
        }
        return total;
    }
}

🛠️ Installation

Global Installation (Recommended)

npm install -g solidity-gas-optimizer

Local Installation

npm install --save-dev solidity-gas-optimizer

🚀 Quick Start

Basic Usage

# Analyze a single file
gas-opt analyze contracts/Token.sol

# Analyze with specific rules
gas-opt analyze contracts/Token.sol --rules storage-read-in-loop,custom-errors

# List all available rules
gas-opt analyze --list-rules

Example Output

╔═══════════════════════════════════════════════════╗
║          Solidity Gas Optimization Tool           ║
╚═══════════════════════════════════════════════════╝

✓ Analyzing: Token.sol

🔍 Gas Optimization Report

🔄 Storage Reads in Loops (2 issues)
──────────────────────────────────────────────────

[1] 🔴 HIGH at line 45
    Storage array length 'balances.length' is being read inside a loop condition

      45 │ for (uint i = 0; i < balances.length; i++) {
              ╰── here

    💡 Suggestion: Cache the array length before the loop:
       uint256 balancesLength = balances.length;
    ⛽ Gas Impact: ~2100 gas per iteration

📊 Summary Report
══════════════════════════════════════════════════
  Severity Distribution:
    High    │ ████████ 4
    Medium  │ ████ 2
    
  Optimization Score: 73/100

📋 Available Rules

| Rule | Description | Impact | |------|-------------|---------| | storage-read-in-loop | Detects storage variables read inside loops | HIGH | | public-vs-external | Suggests using external for non-internal functions | MEDIUM | | state-variable-packing | Identifies inefficient variable ordering | HIGH | | use-custom-errors | Replaces string reverts with custom errors | MEDIUM |

🤝 Contributing

We love contributions! See CONTRIBUTING.md for guidelines.

Adding New Rules

1. Create a new rule in src/rules/
2. Extend the BaseRule class
3. Add to rule registry
4. Submit a PR!

📈 Roadmap

• [x] Core rules implementation
• [x] Beautiful CLI output
• [ ] Config file support (v0.2.0)
• [ ] Auto-fix capability (v0.3.0)
• [ ] VS Code extension (v0.4.0)
• [ ] More optimization rules (ongoing)

📄 License

MIT © I'ts Beerz