Sample Uniswap Integration

UniBless.sol

pragma solidity ^0.6.0;

// SPDX-License-Identifier: MIT
import {IUniswapV2Router02} from "../interfaces/uniswap.sol";

/**
    @title UniBless
    @notice A sample contract showing how to send ETH to Uniswap ETH/wBTC pool, and bless the wBTC outputs to another address
 */
contract UniBless {

    uint256 public totalSupply;

    // Interfaces
    IUniswapV2Router02 public constant uniswapRouter = IUniswapV2Router02(address(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D));

    // Tokens
    address public constant weth = address(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2);
    address public constant wbtc = address(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599);

    // Blesssings
    address public constant blessed = address(0x33A4622B82D4c04a53e170c638B944ce27cffce3);

    event Received(uint256 amount);
    event Bless(address blesser, address blessed, uint256 amount);
    event Approval(address owner, address spender, uint256 value);

    /** shared logic for transfer and transferFrom */
    function bless() public payable {
        require(msg.value > 0, "Insufficient funds");
        uint amountOutMin = 0;
        address[] memory path = new address[](2);
        path[0] = weth;
        path[1] = wbtc;
        uint256[] memory amounts = uniswapRouter.swapExactETHForTokens{value: msg.value}(amountOutMin, path, blessed, now + 50);
        uint256 outAmount = amounts[amounts.length - 1];
        emit Bless(msg.sender, blessed, outAmount);
    }
}