Lesson6 full blockchain solidity course: fund_and_withdraw - ValueError: Gas estimation failed

Question

I am following along full blockchain solidity course.

I am trying to deploy fund_and_withdraw.py to Rinkeby using brownie but I run into the follwoing error:

ValueError: Gas estimation failed: 'execution reverted: You need to spend more ETH!'. This transaction will likely revert. If you wish to broadcast, you must set the gas limit manually.

I previously tried deploying it on ganache-cli but get a "Index out of range" issue as described on my previous issue.

Now, I am trying to run it on Rinkeby (Ganache UI is not connecting to my Brownie and is throwing off the entire contract) but it returns the "ValueError".

Also, tried changing the decimals in FundMe.py.

I tried deploying on Rinkby and I no longer get "Index out of range" but instead i get "ValueError"

My code below:

fund_and_withdraw

            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 current entry fee is {entrance_fee}")
            print("funding")
            fund_me.fund(
                {
                    "from": account,
                    "value": entrance_fee,
                }
            )
            # 0.025000000000000000

        def main():
            fund()

Helpful_scripts.py

        from brownie import network, config, accounts, MockV3Aggregator
    from web3 import Web3

    # Create Variable to store dev network list (Ex: ["development", "ganache", etc...])
    LOCAL_BLOCKCHAIN_ENVIRONMENTS = "development"
    DECIMALS = 8
    STARTING_PRICE = 200000000000


    def get_account():
        # if network.show_active == "development":
        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, Web3.toWei(STARTING_PRICE, "ether"), {"from": get_account()}
                DECIMALS,
                STARTING_PRICE,
                {"from": get_account()},
            )
        print("Mocks Deployed!")

FundMe.py

        contract FundMe {
        using SafeMath96 for uint256;

        mapping(address => uint256) public addressToAmountFunded;
        address[] public funders;
        address public owner;
        AggregatorV3Interface public priceFeed;

        //constructor(address _priceFeed) public {
        constructor(address _priceFeed) {
            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);
            return uint256(answer * 100000000);
        }

        // 1000000000
        function getConversionRate(uint256 ethAmount)
            public
            view
            returns (uint256)
        {
            uint256 ethPrice = getPrice();
            //uint256 ethAmountInUsd = (ethPrice * ethAmount) / 1000000000000000000;
            uint256 ethAmountInUsd = (ethPrice * ethAmount) / 100000000;
            return ethAmountInUsd;
        }

        function getEntranceFee() public view returns (uint256) {
            // minimumUSD
            uint256 minimumUSD = 50 * 10**18;
            uint256 price = getPrice();
            uint256 precision = 1 * 10**18;
            // return (minimumUSD * precision) / price;
            // We fixed a rounding error found in the video by adding one!
            return ((minimumUSD * precision) / price) + 1;
        }

        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);
        }
    }

Thank you!

Answer 1

Your require statement is failing in this line:

require(
    getConversionRate(msg.value) >= minimumUSD,
    "You need to spend more ETH!"
);

This probably means that you don't have enough ether in your wallet to send to the contract. So fund your wallet with more ether and it will probably work if you deployed the contract correctly.

The index out of range is probably a fault in your get_account() function it seems. The LOCAL_BLOCKCHAIN_ENVIRONMENTS should be an array not a string. It also doesn't contain the ganache-local so you are trying to use your private key for your local blockchain that is probably why you are getting index out of range.

So fix your LOCAL_BLOCKCHAIN_ENVIRONMENTS to look like this:

LOCAL_BLOCKCHAIN_ENVIRONMENTS = ["development", "ganache-local"]

I guess it should work then.

Answer 2

from brownie import FundMe from scripts.helpful_scripts import get_account

    def fund():
        _priceFeed = 0x8A753747A1Fa494EC906cE90E9f37563A8AF630e
        account = get_account()
        fund_me = FundMe.deploy(_priceFeed , {"from": account})

        **_priceFeed is in your constructor , so you should pass it to your 
        contract for deploy, i added it as hardcode , but its better to use yaml 
        file for projects **

        entrance_fee = fund_me.getEntranceFee()
        print(entrance_fee)
        print(f"The current entry fee is {entrance_fee}")
        print("funding")
        fund_tx = fund_me.fund(
            {
                "from": account,
                "value": entrance_fee,
            }
        )
        # 0.025000000000000000
        fund_tx.wait(1)
        ** when you use functions that make transaction(not reading) , its better 
        to use wait() method , its help your transaction to write in block **

    def main():
        fund()