brownie部署与测试智能合约

Posted 2021-12-09 sanqima

    brownie是一种Python语言的开发与测试框架，它可以部署.sol、.py格式的智能合约。

• 完全支持Solidity和Vyper
• 通过pytest进行智能合约测试，包括基于跟踪的覆盖率评估
• 通过hypothesis进行基于属性和状态的测试
• 强大的调试工具，包括python风格的跟踪和自定义错误字符串
• 内置控制台，用于快速项目互动
• 支持ethPM软件包

    下面，介绍brownie的安装、部署智能合约、测试智能合约。

1、准备环境

1.1 安装nodejs、python3

    安装nodejs，请参考这篇文章的第1节
    安装Python3，请参考这篇文章的第9节

1.2 安装brownie

    这里选择brownie==1.12.3版本，进行安装

pip3 install eth-brownie==1.12.3

1.3 安装ganache-cli

npm install -g ganache-cli

2、创建工程browthree

2.1 创建文件与文件夹

    a) 打开控制台终端，依次输入如下命令：

mkdir browthree
cd browthree
brownie init
touch brownie-config.yaml
touch .env

    b) 填写brownie的配置文件：brownie-config.yaml
    // brownthree/brownie-config.yaml

dependencies:
  - OpenZeppelin/openzeppelin-contracts@3.4.0
compiler:
  solc:
    remappings:
      - '@openzeppelin=OpenZeppelin/openzeppelin-contracts@3.4.0'
dotenv: .env
networks:
    networks:
        # any settings given here will replace the defaults
        development:
            host: http://127.0.0.1
            gas_price: 0
            persist: false
            reverting_tx_gas_limit: 6721975
            test_rpc:
                cmd: ganache-cli
                port: 8545
                gas_limit: 6721975
                accounts: 10
        # set your Infura API token to the environment variable ${WEB3_INFURA_PROJECT_ID}
        mainnet:
            host: https://mainnet.infura.io/v3/${WEB3_INFURA_PROJECT_ID}
        goerli:
            host: https://goerli.infura.io/v3/${WEB3_INFURA_PROJECT_ID}
        kovan:
            host: https://kovan.infura.io/v3/${WEB3_INFURA_PROJECT_ID}
        rinkeby:
            host: https://rinkeby.infura.io/v3/${WEB3_INFURA_PROJECT_ID}
        ropsten:
            host: https://ropsten.infura.io/v3/${WEB3_INFURA_PROJECT_ID}
        classic:
            host: https://www.ethercluster.com/etc
        kotti:
            host: https://www.ethercluster.com/kotti
wallets:
  from_key: ${PRIVATE_KEY}

    c) 填写环境变量文件: .env
    // brownthree/.env

export WEB3_INFURA_PROJECT_ID='59...b6'
export PRIVATE_KEY='85...84'

    d) browthree工程的目录结构

图(1) browthree工程的目录结构

2.2 编写智能合约

    在browthree/contracts目录，创建一个智能合约文件: HelloERC20.sol

cd browthree/contracts
touch HelloERC20.sol

    // HelloERC20.sol

pragma solidity >=0.4.22 <0.6.0;

interface tokenRecipient { 
    function receiveApproval(address _from, uint256 _value, address _token, bytes calldata _extraData) external; 
}

contract HelloERC20 {
    // Public variables of the token
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    // 18 decimals is the strongly suggested default, avoid changing it
    uint256 public totalSupply;

    // This creates an array with all balances
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
    event Transfer(address indexed from, address indexed to, uint256 value);
    
    // This generates a public event on the blockchain that will notify clients
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);

    constructor(
        uint256 initialSupply,
        string memory tokenName,
        string memory tokenSymbol
    ) public {
        totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balanceOf[msg.sender] = totalSupply;                // Give the creator all initial tokens
        name = tokenName;                                   // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
    }

    /**
     * Internal transfer, only can be called by this contract
     */
    function _transfer(address _from, address _to, uint _value) internal {
        // Prevent transfer to 0x0 address. Use burn() instead
        require(_to != address(0x0));
        // Check if the sender has enough
        require(balanceOf[_from] >= _value);
        // Check for overflows
        require(balanceOf[_to] + _value >= balanceOf[_to]);
        // Save this for an assertion in the future
        uint previousBalances = balanceOf[_from] + balanceOf[_to];
        // Subtract from the sender
        balanceOf[_from] -= _value;
        // Add the same to the recipient
        balanceOf[_to] += _value;
        emit Transfer(_from, _to, _value);
        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
    }

    function transfer(address _to, uint256 _value) public returns (bool success) {
        _transfer(msg.sender, _to, _value);
        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender] -= _value;
        _transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint256 _value) public
        returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }

    function approveAndCall(address _spender, uint256 _value, bytes memory _extraData)
        public
        returns (bool success) {
        tokenRecipient spender = tokenRecipient(_spender);
        if (approve(_spender, _value)) {
            spender.receiveApproval(msg.sender, _value, address(this), _extraData);
            return true;
        }
    }

    function burn(uint256 _value) public returns (bool success) {
        require(balanceOf[msg.sender] >= _value);   // Check if the sender has enough
        balanceOf[msg.sender] -= _value;            // Subtract from the sender
        totalSupply -= _value;                      // Updates totalSupply
        emit Burn(msg.sender, _value);
        return true;
    }

    function burnFrom(address _from, uint256 _value) public returns (bool success) {
        require(balanceOf[_from] >= _value);                // Check if the targeted balance is enough
        require(_value <= allowance[_from][msg.sender]);    // Check allowance
        balanceOf[_from] -= _value;                         // Subtract from the targeted balance
        allowance[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
        totalSupply -= _value;                              // Update totalSupply
        emit Burn(_from, _value);
        return true;
    }
}

2.3 编写测试脚本

    在browthree/tests目录，创建一个测试脚本文件: 1_func_test.py

cd browthree/tests
touch 1_func_test.py

    // 1_func_test.py

import pytest
from brownie import HelloERC20, accounts


@pytest.fixture
def token():
    return accounts[0].deploy(HelloERC20, 1000,"AppleToken", "APT")

def test_transfer(token):
    token.transfer(accounts[1], "100 ether", {'from': accounts[0]})
    assert token.balanceOf(accounts[0]) == "900 ether"

def test_name(token):
    assert token.name() == "AppleToken"

def test_symbol(token):
    assert token.symbol() == "APT"

def test_totalSupply(token):
    assert token.totalSupply() == "1000 ether"

def test_approve(token):
    token.approve(accounts[1],"100 ether",{'from':accounts[0]})
    assert token.allowance(accounts[0],accounts[1]) == "100 ether"

def test_burn(token):
    token.burn("100 ether",{'from':accounts[0]})
    print("addr=",token.address)
    assert token.totalSupply() == "900 ether"

def test_transferFrom(token):
    token.approve(accounts[1],"100 ether",{'from':accounts[0]})
    token.transferFrom(accounts[0],accounts[1],"100 ether",{'from':accounts[1]})
    assert token.balanceOf(accounts[1]) == "100 ether"

def test_burnFrom(token):
    token.approve(accounts[1],"100 ether",{'from':accounts[0]})
    token.burnFrom(accounts[0],"100 ether",{'from':accounts[1]})
    assert token.totalSupply() == "900 ether"

2.4 编写部署脚本

    在browthree/tests目录，创建一个部署脚本文件: 1_deploy_token.py

cd browthree/scripts
touch 1_deploy_token.py

    // 1_deploy_token.py

import os
from brownie import accounts,HelloERC20

initial_supply = 1000000  # 1000000
token_name =   "AppleToken"
token_symbol = "APT"


def get_account():
    accAddr = accounts.add(os.getenv('PRIVATE_KEY'))
    return accAddr

def main():
    account = get_account()
    print('account=',account)
    erc20 = HelloERC20.deploy(
        initial_supply, token_name, token_symbol, {"from": account}
    )

2.5 进行部署与测试

    a) 部署合约到Rinkeby

## 使能.env环境
source .env

## 部署到Rinkeby
brownie run scripts/1_deploy_token --network rinkeby

    效果如下：

图(2) 部署合约到Rinkeby

    得到HelloERC20.sol的合约地址为: 0x7000A28DCF57883286bd568CCa4733baF91e62ef

    b) 测试HelloERC20合约

• 先启动ganache-cli

    在黑框框终端里，输入如下命令即可

ganache-cli

• 再运行测试脚本

brownie test tests/1_func_test.py

    效果如下：

图(3) 在ganache-cli里，测试合约

参考文献

brownie 单元测试