Lesson6: VirtualMachineError: revert

[ace-brown]

Hi everybody. I was trying to run fund_and_withdraw file and i received this error.

This is the error:

INFO: Could not find files for the given pattern(s).
Brownie v1.17.0 - Python development framework for Ethereum

BrownieFundMeProject is the active project.

Running '\Web development\My projects\Blockchain projects\brownie_fund_me\scripts\fund_and_withdraw.py::main'...
  File "C:\Users\kazem\.local\pipx\venvs\eth-brownie\lib\site-packages\brownie\_cli\run.py", line 50, in main    
    return_value, frame = run(
  File "C:\Users\kazem\.local\pipx\venvs\eth-brownie\lib\site-packages\brownie\project\scripts.py", line 103, in 
run
    return_value = f_locals[method_name](*args, **kwargs)
  File "\Web, line projects\Blockchain, in line
    fund()
  File "\Web, line projects\Blockchain, in line
    entrance_fee = fund_me.getEntranceFee()
  File "C:\Users\kazem\.local\pipx\venvs\eth-brownie\lib\site-packages\brownie\network\multicall.py", line 115, in _proxy_call
    result = ContractCall.__call__(*args, **kwargs)  # type: ignore
  File "C:\Users\kazem\.local\pipx\venvs\eth-brownie\lib\site-packages\brownie\network\contract.py", line 1658, in __call__
    return self.call(*args, block_identifier=block_identifier)
  File "C:\Users\kazem\.local\pipx\venvs\eth-brownie\lib\site-packages\brownie\network\contract.py", line 1454, in call
    raise VirtualMachineError(e) from None
VirtualMachineError: revert```

[cromewar]

Could you provide more info please? plz show us the contract code and the python script code.

[ace-brown]

FundMe.sol

pragma solidity ^0.6.6;

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;
    constructor(address _pricefeed) public {
        priceFeed = AggregatorV3Interface(_pricefeed);
        owner = msg.sender;
    }
    
    function fund() public payable {
        uint256 minimumUSD = 50 * 10 ** 18;
        require(getConversionRate(msg.value) >= minimumUSD, "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() payable onlyOwner public {
        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);
    }
}

[ace-brown]

deploy.py

from scripts.helpful_scripts import (
     get_account,
     deploy_mocks, 
     LOCAL_BLOCKCHAIN_ENVIRONMENTS,
)


def deploy_fund_me():
     account = get_account()
     if network.show_active() not in LOCAL_BLOCKCHAIN_ENVIRONMENTS:
          price_feed_address = config["networks"] [network.show_active()] [
          "eth_usd_price_feed"
          ]
     else:
          deploy_mocks()
          price_feed_address = MockV3Aggregator[-1].address

     fund_me = FundMe.deploy(
          price_feed_address,
          {"from": account},
          publish_source=config["networks"] [network.show_active()].get("verify"),
     ) 
     print(f"Contract deployed to {fund_me.address}") 
     return fund_me

def main():
    deploy_fund_me() ```

[ace-brown]

fund_and_withdraw.py

from scripts.helpful_scripts import get_account

def fund():
    fund_me = FundMe[-1]
    account = get_account()
    entrance_fee = fund_me.getEntranceFee()
    print(entrance_fee)
    print(f"The current entry fee is {entrance_fee}")
    print("Funding")
    fund_me.fund({"from": account, "value": entrance_fee})


def main():
    fund()
    ```

[ace-brown]

helpful_scripts.py

from web3 import Web3

LOCAL_BLOCKCHAIN_ENVIRONMENTS = ["development", "ganache-loca-2"]

DECIMALS = 8
STARTING_PRICE = 200000000000

def get_account():
    if network.show_active() in LOCAL_BLOCKCHAIN_ENVIRONMENTS:
        return accounts[0]
    else:
        return accounts.add(config["wallets"]["from_key"])

def deploy_mocks():
        print(f"The active network is {network.show_active()}")
        print("Deploying Mocks...")
        if len(MockV3Aggregator) <= 0:
            MockV3Aggregator.deploy(DECIMALS, STARTING_PRICE, {"from": get_account()})
        print("Mocks Deployed!") ```

[ace-brown]

brownie-config.yaml

  # - <organization/repo>@<version>
  - smartcontractkit/chainlink-brownie-contracts@1.1.1
compiler:
  solc:
    remappings:
      - "@chainlink=smartcontractkit/chainlink-brownie-contracts@1.1.1"

dotenv: .env

networks:
  rinkeby:
    eth_usd_price_feed: "0x8A753747A1Fa494EC906cE90E9f37563A8AF630e"
    verify: True
  development:
    verify: False
  ganache-loca-2:
    verify: False
  ganache-local-3:
    verify: False
wallets:
  from_key: ${PRIVATE_KEY}

[ace-brown]

.env

export WEB3_INFURA_PROJECT_ID=7c649f11ba9543b7813eb3ebdbc75051
export ETHERSCAN_TOKEN=B4BDBN22J9E38JTV4HRXKHXPQD3RE18234 ```

[ace-brown]

This is a pic from my ide and its files

[ace-brown]

Thank you so much in advance.

[cromewar]

I'll review your code and try to find the error

[ace-brown]

After reviewing my codes, I managed to solve the problem in the following way:
First, I deleted this folder

Then restart ganache and VSCode, then deleted the ganache-local i added at the first place and added the ganache-local again and it's working properly now.

[cromewar]

I'm glad you managed to solve it, because I didn't find anything wrong on your code.