Swapping App

Overview

A smart contract application that enables secure token swapping using the Uniswap V2 Router on EVM-compatible blockchains. The contract provides a streamlined interface for executing token swaps with automatic liquidity pool detection and slippage protection.

Features

• Token Swapping: Execute direct token-to-token swaps via Uniswap V2 Router
• Multi-hop Support: Support for complex swap paths with multiple token intermediaries
• Slippage Protection: Built-in minimum output amount validation to protect against price fluctuations
• Safe Token Handling: Uses OpenZeppelin's SafeERC20 for secure token transfers
• Event Emission: Comprehensive event logging for swap transactions
• Flexible Routing: Configure custom router addresses for different blockchain networks

Contract Architecture

SwapApp.sol

The main contract that handles token swap execution through Uniswap V2 Router.

Key Functions:

• swapTokens() - Execute a swap with specified token path, amount, and minimum output

Events:

• SwapTokens() - Emitted when a successful swap is executed

Supported Networks

• Sepolia Testnet: Router at 0xeE567Fe1712Faf6149d80dA1E6934E354124CfE3
• Arbitrum One: Router at 0x4752ba5dbc23f44d87826276bf6fd6b1c372ad24

Installation

# Clone the repository
git clone <repository-url>
cd Swapping-App

# Install dependencies
forge install

# Build the project
forge build

Testing

Run Tests with Sepolia Fork

# Run all tests with Sepolia testnet fork
forge test --fork-url https://ethereum-sepolia-rpc.publicnode.com -vvv

# Run specific test
forge test --fork-url https://ethereum-sepolia-rpc.publicnode.com --match-test testSwapTokensProperly -vvv

Code Coverage

# Generate coverage report with Sepolia fork
forge coverage --fork-url https://ethereum-sepolia-rpc.publicnode.com

Current Coverage:

╭-----------------+---------------+---------------+---------------+---------------╮
| File            | % Lines       | % Statements  | % Branches    | % Funcs       |
+=================================================================================+
| src/SwapApp.sol | 100.00% (7/7) | 100.00% (6/6) | 100.00% (0/0) | 100.00% (2/2) |
|-----------------+---------------+---------------+---------------+---------------|
| Total           | 100.00% (7/7) | 100.00% (6/6) | 100.00% (0/0) | 100.00% (2/2) |
╰-----------------+---------------+---------------+---------------+---------------╯

Dependencies

• OpenZeppelin Contracts: ERC20 token interface and SafeERC20 utilities
• Uniswap V2 Router: Decentralized exchange routing

Security Considerations

• Slippage Protection: Always set an appropriate amountOutMin to prevent sandwich attacks
• Deadline Validation: Include transaction deadline to prevent expired transactions
• Liquidity Verification: Ensure adequate liquidity exists in swap pools before execution
• SafeERC20: All token operations use safe transfer wrappers

Project Structure

Swapping-App/
├── src/
│   ├── SwapApp.sol                 # Main swap contract
│   └── interfaces/
│       └── IV2Router02.sol         # Uniswap V2 Router interface
├── test/
│   └── SwapApp.t.sol              # Test suite
├── lib/                            # External dependencies
├── foundry.toml                    # Foundry configuration
└── README.md                       # This file

License

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

Contributing

Contributions are welcome! Please ensure:

• All tests pass
• Code coverage remains at 100%
• Follow Solidity best practices
• Add tests for new functionality

Contact

For questions or support, please open an issue on the GitHub repository.