brownie AttributeError: 'NoneType' object has no attribute 'getEntranceFee'

Question

Macbook Pro：蒙特雷

英特尔酷睿 i7

布朗尼 v1.17.2

我正在根据参考学习solidity(https://www.youtube.com/watch?v=M576WGiDBdQ&t=25510s)。

我在这里尝试做的是使用 brownie 在脚本 (deploy.py) 中部署合约 (FundMe)，然后编写测试脚本 (test_can_fund_and_withdraw.py)

当我运行测试 script.I 认为这是因为在测试脚本中导入没有函数“getEntranceFee”的函数“deploy_fund_me()”时发生错误()”，应该从合同中导入 FundMe.sol 但在 youtube 课程中，它工作正常。

测试脚本(test_can_fund_and_withdraw.py)

deploy.py 错误信息

合同FundMe.sol

// SPDX-License-Identifier: MIT

pragma solidity 0.8.0;

// we need tell brownie @chainlink means == what input in config,need to tell compiler

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;
    AggregatorV3Interface public priceFeed;

    // if you're following along with the freecodecamp video
    // Please see https://github.com/PatrickAlphaC/fund_me
    // to get the starting solidity contract code, it'll be slightly different than this!
    constructor(address _priceFeed) {
        // make price feed a parameter
        priceFeed = AggregatorV3Interface(_priceFeed);
        owner = msg.sender;
    }

    function fund() public payable {
        uint256 mimimumUSD = 50 * 10**18;
        require(
            getConversionRate(msg.value) >= mimimumUSD,
            "You need to spend more ETH!"
        );
        addressToAmountFunded[msg.sender] += msg.value;
        funders.push(msg.sender);
    }

    function getVersion() public view returns (uint256) {
        return priceFeed.version();
    }

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

    // 1000000000
    function getConversionRate(uint256 ethAmount)
        public
        view
        returns (uint256)
    {
        uint256 ethPrice = getPrice();
        uint256 ethAmountInUsd = (ethPrice * ethAmount) / 1000000000000000000;
        return ethAmountInUsd;
    }

    function getEntranceFee() public view returns (uint256) {
        // mimimumUSD
        uint256 mimimumUSD = 50 * 10**18;
        uint256 price = getPrice();
        uint256 precision = 1 * 10**18;
        return (mimimumUSD * precision) / price;
    }

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    function withdraw() public payable onlyOwner {
        payable(msg.sender).transfer(address(this).balance);

        for (
            uint256 funderIndex = 0;
            funderIndex < funders.length;
            funderIndex++
        ) {
            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }
        funders = new address[](0);
    }
}

Answer 1

在 deploy.py 中你没有 returning 任何东西。你应该

return fund_me

当您在测试脚本中调用 deploy_fund_me 时，它会 return 合同以便您可以调用这些方法。

brownie AttributeError: 'NoneType' object has no attribute 'getEntranceFee'

brownie AttributeError: 'NoneType' object has no attribute 'getEntranceFee'

python

ethereum

solidity

smartcontracts

brownie