Lesson 6: fund_and_withdraw.py script error....

[toddabraham]

Trying to run my fund_and_withdraw.py sript from brownie and getting the error VirtualMachineError: revert message.

I seem unable to find any information that helps me understand this error and how to resolve it. Is anyone able to offer guidance?

[toddabraham]

Patrick Edit: The fix was to go back and find a typo or missing "something"

Now I'm getting this error.....

[PatrickAlphaC]

Thanks for making this. How did you solve the last issue?

Can you please add:

1. Exactly what your script looks like
2. What your contract looks like
3. The text of your error

Instead of adding images?

[AlbertoSinigaglia]

you are probably passing a parameter with default value to None to the smart contract

[toddabraham]

@PatrickAlphaC @AlbertoSinigaglia

1. The VitrualMachineError: revert issue turned into ValueError: No data was returned - the call likely reverted after restarting ganache-cli.

2. SCRIPT fund_and_withdraw.py

from brownie import FundMe
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 entrance fee is {entrance_fee}")
print("Funding")
fund_me.fund({"from": account, "value": entrance_fee})

def main():
fund()

3. CONTRACT FundMe.sol

// SPDX-License-Identifier: MIT

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;

constructor() public {
    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) {
    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);
}

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

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

function withdraw() public payable onlyOwner {
    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);
}

}

4. CONFIG brownie-config.yaml

dependencies:

- <organization/repo>@

• smartcontractkit/chainlink-brownie-contracts@1.1.1
  compiler:
  solc:
  remappings:
  • '@chainlink=smartcontractkit/chainlink-brownie-contracts@1.1.1'
    dotenv: .env
    networks:
    default: development
    rinkeby:
    eth_usd_price_feed: '0x594B45Fc8Fe429BfdBbC809099B77870B747205d'
    verify: True
    development:
    verify: False
    ganache-local:
    verify: False
    wallets:
    from_key: ${PRIVATE_KEY}

5. ERROR TEXT

unning 'scripts/fund_and_withdraw.py::main'...
File "brownie/_cli/run.py", line 49, in main
return_value, frame = run(
File "brownie/project/scripts.py", line 103, in run
return_value = f_locals[method_name](*args, **kwargs)
File "./scripts/fund_and_withdraw.py", line 22, in main
fund()
File "./scripts/fund_and_withdraw.py", line 8, in fund
entrance_fee = fund_me.getEntranceFee()
File "brownie/network/multicall.py", line 115, in _proxy_call
result = ContractCall.call(*args, **kwargs) # type: ignore
File "brownie/network/contract.py", line 1729, in call
return self.call(*args, block_identifier=block_identifier)
File "brownie/network/contract.py", line 1539, in call
raise ValueError("No data was returned - the call likely reverted")
ValueError: No data was returned - the call likely reverted

[toddabraham]

Backed up to the beginning of lesson 6, made a couple of changes (one was that I found my rinkeby address was incorrect). Fixed and moving on.

[AlbertoSinigaglia]

@toddabraham good job, just as a note, you can use three back ticks to insert code and be highlighted:

```python
from Y import X
```

[adele013]

Hey sorry but i dont know how you fixed the revert problem. I am having the same issue.

[cromewar]

Hello @adele013 could you please share more info about your error, the author of this thread said that his rinkeby address was incorrect, does this make any sense to you?