Lesson 4 Gas estimation error

[GreatApe78]

when i try to withdraw this error occurs

Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending?
gas required exceeds allowance (30000000)

//SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;



import "./PriceConverter.sol";


contract FundMe{
       modifier onlyOwner {
        require(msg.sender==owner,"Sender is not owner!");
        _;
 
    }


    using PriceConverter for uint256;

    uint256 public minimunUsd= 50*1e18;


    address[] public  funders;

    mapping(address=>uint256) public addressToAmountFunded;

    address public owner;

    constructor(){
        owner = msg.sender;
        




    }


    function fund() public payable{

        //setar valor mínimo de dinheiro
        //usei oracle chainlink para pegar o valor do ether em dolar
        
        require(msg.value.getConversionRate() >= minimunUsd, "Didnt Send enough");

        //dezoito casas decimais

        funders.push(msg.sender);

        addressToAmountFunded[msg.sender] = msg.value;

    }

    function withdraw() public  onlyOwner{
 
        for(uint256 funderIndex = 0;funderIndex<funders.length;funderIndex = funderIndex++){

            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }


        funders = new address[](0);


 /*      TRANSFER --- payable(msg.sender).transfer(address(this).balance);
            
        SEND ----bool sendSuccess = payable(msg.sender).send(address(this).balance);
           
        require(sendSuccess,"Send Failed");
 */

    (bool callSuccess,) = payable(msg.sender).call{value: address(this).balance }("");


   
    require(callSuccess,"Call failed");
   

    }






}

[othaime-en]

Hey @GreatApe78 try these quick fixes: Make sure you are sending enough ETH and also make your withdraw function payable and see if they solve your issue.

[adith-p]

Gas estimation error is caused when the required gas is way higher than that of what you have entered.
Our its just your balance is low make sure to keep it above .2 befor retrying
Note:
I also encountered this issue right now the gas prices is 50/1500 = 0.0333333333
Put the wei value =40000000000000000
At the time of post

[alymurtazamemon]

@GreatApe78 Check this one! Because ETH price is decreased, so you have to fund based on the current price.

[imlevelhead]

Still having this issue on Goerli testnet (the recommended testnet by Chainlink). At first I thought the issue was that the contract needed the correct Goerli ETH/USD data feed (0xD4a33860578De61DBAbDc8BFdb98FD742fA7028e) but that hasn't changed anything.

Otherwise the code is copy-pasted from the repo
Wallet balance of 0.29 GoerliETH

[adith-p]

Share the code.

[imlevelhead]

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.8;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
import "./PriceConverter.sol";

error NotOwner();

contract FundMe {
    using PriceConverter for uint256;

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

    // Could we make this constant?  /* hint: no! We should make it immutable! */
    address public /* immutable */ i_owner;
    uint256 public constant MINIMUM_USD = 50 * 10 ** 18;
    
    constructor() {
        i_owner = msg.sender;
    }

    function fund() public payable {
        require(msg.value.getConversionRate() >= MINIMUM_USD, "You need to spend more ETH!");
        // require(PriceConverter.getConversionRate(msg.value) >= MINIMUM_USD, "You need to spend more ETH!");
        addressToAmountFunded[msg.sender] += msg.value;
        funders.push(msg.sender);
    }
    
    function getVersion() public view returns (uint256){
        AggregatorV3Interface priceFeed = AggregatorV3Interface(	0xD4a33860578De61DBAbDc8BFdb98FD742fA7028e);
        return priceFeed.version();
    }
    
    modifier onlyOwner {
        // require(msg.sender == owner);
        if (msg.sender != i_owner) revert NotOwner();
        _;
    }
    
    function withdraw() payable onlyOwner public {
        for (uint256 funderIndex=0; funderIndex < funders.length; funderIndex++){
            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }
        funders = new address[](0);
        // // transfer
        // payable(msg.sender).transfer(address(this).balance);
        // // send
        // bool sendSuccess = payable(msg.sender).send(address(this).balance);
        // require(sendSuccess, "Send failed");
        // call
        (bool callSuccess, ) = payable(msg.sender).call{value: address(this).balance}("");
        require(callSuccess, "Call failed");
    }
    // Explainer from: https://solidity-by-example.org/fallback/
    // Ether is sent to contract
    //      is msg.data empty?
    //          /   \ 
    //         yes  no
    //         /     \
    //    receive()?  fallback() 
    //     /   \ 
    //   yes   no
    //  /        \
    //receive()  fallback()

    fallback() external payable {
        fund();
    }

    receive() external payable {
        fund();
    }

}

// Concepts we didn't cover yet (will cover in later sections)
// 1. Enum
// 2. Events
// 3. Try / Catch
// 4. Function Selector
// 5. abi.encode / decode
// 6. Hash with keccak256
// 7. Yul / Assembly

[imlevelhead]

WOW 🤦🏽‍♂️ ok looks like my problem was the spacing on AggregatorV3Interface priceFeed = AggregatorV3Interface( 0xD4a33860578De61DBAbDc8BFdb98FD742fA7028e); I didn't see it on remix because I had text wrapping on.

So.. original problm of gas estimation is solved by using the correct ETH/USD data feed for the chain you are testing with!

[adith-p]

Told ya

[krakxn]

Is this resolved?

[dimit4hll]

I got the same error. "Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending?
gas required exceeds allowance (30000000)".
And I'm using the correct ETH/USD data feed(Goerli Testnet) and still I have issue.
Anyone to know other way how to fix this?

[Manishsahusahu]

Use correct address by taking from docs.chain.link site. Try to decrease the minimum USD by lowering it from 50USD. Make sure you have sufficient balance in your wallet.