FundMe.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;

import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol";
import "@chainlink/contracts/src/v0.6/vendor/SafeMathChainlink.sol";

contract FundMe {
    using SafeMathChainlink for uint256;

    mapping(address => uint256) public addressToAmountFunded;
    address[] public funders;
    address public owner;
    // constructor gets automatically triggered once the contract gets deployed
    constructor() public {
        owner = msg.sender;
    }

    function fund() public payable {
        // 50$
        uint256 minimumUSD = 50 * 10 ** 18;
        require(getConversionRate(msg.value) >= minimumUSD, "You need to send at least 50$ worth of ETH");
        addressToAmountFunded[msg.sender] += msg.value;
        funders.push(msg.sender);

    }

    function getVersion() public view returns (uint256) {
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        return priceFeed.version();
    }

    function getPrice() public view returns (uint256) {
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        (,int256 answer,,,) = priceFeed.latestRoundData();
        return uint256(answer * 10000000000);
    }

    function getConversionRate(uint256 ethAmount) public view returns (uint256) {
        uint256 ethPrice = getPrice();
        uint256 ethAmountInUSD = (ethAmount * ethPrice) / 1000000000000000000;
        return ethAmountInUSD;
    }

    modifier onlyOwner {
        require(msg.sender == owner, "Only the owner is authorized to trigger this function");
        _;
    }

    function withDraw() payable onlyOwner public {
        msg.sender.transfer(address(this).balance);
        // update the balance of each funder after withdrawal
        for (uint256 funderIndex=0; funderIndex<funders.length; funderIndex++) {
            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }
        // instantiate a new funders array
        funders = new address[](0);
    }
}