Error: could not decode result data (value="0x", info={ "method": "priceFeed", "signature": "priceFeed()" }, code=BAD_DATA, version=6.6.4)

[Atharv-02]

Hi Sir,
While testing the hardhat fund me smart contract, I am getting the following error ----

unit test - FundMe.test.js -

const { assert, expect } = require("chai");
const { deployments, ethers, getNamedAccounts } = require("hardhat");

describe("FundMe", function () {
  let fundMe, deployer, mockV3Aggregator;
  const sendValue = ethers.parseEther("1");
  beforeEach(async function () {
    deployer = (await getNamedAccounts()).deployer;
    await deployments.fixture(["all"]);
    fundMe = await ethers.getContractAt("FundMe", deployer);
    mockV3Aggregator = await ethers.getContractAt("MockV3Aggregator", deployer);
    console.log(await mockV3Aggregator.getAddress());
  });

  describe("constructor", () => {
    it("Sets the aggregator Address", async () => {
      const response = await fundMe.priceFeed();
      assert.equal(response, await mockV3Aggregator.address);
    });
  });

The smart contract is written below ----

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

//Imports
import "./PriceConverter.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
// Error Codes
error FundMe__NotOwner();
// Interfaces, Liberaries, Contracts
/**@title A contract for crowdfunding
 * @author Atharv Gulati
 * @notice This contract is to demo a sample funding contract
 * @dev This impliments priceFeeds as our library
 * 
*/
contract FundMe {
    // Type declarations
    using PriceConverter for uint256;
    // State variables
    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;
    AggregatorV3Interface public priceFeed;
    // Modifiers
    modifier onlyOwner {
        // require(msg.sender == owner);
        if (msg.sender != i_owner) revert FundMe__NotOwner();
        _;
    }
    // Rest of the functions
    constructor( address priceFeedAddress) {
        priceFeed=AggregatorV3Interface (priceFeedAddress);
        i_owner = msg.sender;
    }

    function fund() public payable {
        require(msg.value.getConversionRate(priceFeed) >= 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 withdraw() public onlyOwner {
        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();
    }

    function getPriceFeed() public view returns (AggregatorV3Interface) {
        return priceFeed;
    }
    
    function cheaperWithdraw()public payable onlyOwner {
        address[] memory all_funders=funders;
        for (uint256 funderIndex=0; funderIndex < all_funders.length; funderIndex++){
            address funder = all_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");
        
    }
}

Someone please help! I am stuck on this error for 5 days now

[Atharv-02]

https://github.com/Atharv-02/hardhat-fundme-fcc-test.git
This is my github repo incase anyone needs to see

I have gone all over stack overflow, stack exchange eth and even the discussions that take place on this forum but no solution seems to be working for me

[alfaqi]

try change getContractAt to getContract
1- FundMe.test.js file

    fundMe = await ethers.getContract("FundMe", deployer);
    mockV3Aggregator = await ethers.getContract("MockV3Aggregator", deployer);

2- hardhat.config.js file, add this import line

require("@nomiclabs/hardhat-ethers");

3- FundMe.test.js file, you're going to use ethersV6, so change address to target or getAddress()
like this

      assert.equal(response, mockV3Aggregator.target);

I think the issue with getContractAt
but I suggest you use ethersV5 to follow along with the course.

[albaceo12]

hi @alfaqi ..is the code you did write for testing(unit test) working right for you

[alfaqi]

Hey @albaceo12 yes, it is working fine.

[albaceo12]

ok..i got it... i just did waht you said about @nomiclabs/hardhat-ethers..and it worked for me right....tnx alot @alfaqi

[GhtZzzz]

https://github.com/satishnvrn/hardhat-fund-me-sat/blob/main/test/staging/FundMe.staging.test.ts

[Atharv-02]

Hi @GhtZzzz
PHEWWW I FINALLYY FIGURED IT OUTT
It wouldn't have been possible without your help
Thanks a lottt

Just one last question --

I have used the chainlink aggregator V3 interface but each time I used the price conversion, why do I not end up spending some link

[GhtZzzz]

Hi @GhtZzzz

PHEWWW I FINALLYY FIGURED IT OUTT

It wouldn't have been possible without your help

Thanks a lottt

Just one last question --

I have used the chainlink aggregator V3 interface but each time I used the price conversion, why do I not end up spending some link

hello！I'm very happy to be able to help you .The method of checking prices should not cost gas, is that what it means

[honxsinatra]

What have you done to solve your issue? so that other people like me can take up your way?

[GhtZzzz]

https://github.com/satishnvrn/hardhat-fund-me-sat/blob/feature/test-fixes/test/unit/FundMe.test.ts

[Atharv-02]

No no
What I am saying is that how do I pass in fundMe contract address in ethers.getContractAt

[GhtZzzz]

No no

What I am saying is that how do I pass in fundMe contract address in ethers.getContractAt
………………await fundMe.getAddress()

[Atharv-02]

But how do I do that because ethers.getContractAt is creating the fundMe instance

[Atharv-02]

I obviously can not do this -

address=await fundMe.getAddress()
fundMe = await ethers.getContractAt("FundMe", deployer);

[Atharv-02]

please help
I am stuck on this for almost a week now

[albaceo12]

im still getting the error "could not decode...." what did you do for that...change the ether version or sth else
could you guys give me some expla

[albaceo12]

const {assert} = require("chai")
const {getNamedAccounts, deployments, ethers} = require("hardhat")

describe("", function () {
    let fundme, deployer, mockV3Aggregator
    beforeEach(async () => {
        // const accounts = await ethers.getSigners()
        // const accountZero = accounts[0]
        deployer = (await getNamedAccounts()).deployer
        await deployments.fixture(["all"])
        fundme = await ethers.getContractAt("FundMe", deployer)
        mockV3Aggregator = await ethers.getContractAt(
            "MockV3Aggregator",
            deployer,
        )
    })
    describe("constructor", () => {
        it("sets the aggregator address correctly", async () => {
            const response = await fundme.getPriceFeed()
            assert.equal(response, await mockV3Aggregator.getAddress())
        })
    })
})

[albaceo12]

and i checked its pkg.json and aligned my pkg.json to it but im still getting the error..is your code woking for this testing right?...if yes could you share with me your pkg.json and unit test(updated)

[honxsinatra]

have you got the solution?

[albaceo12]

well here is my repo link : https://github.com/albaceo12/hardhat-fundme-fcc ...check the test code (constructor part) and package.json only need "@nomiclabs/hardhat-ethers": "npm:hardhat-deploy-ethers", just copy there and use npm i --force..with this way its working right for me

[honxsinatra]

Thanks man, i just wanted to know if you have solved the issue, just wanted to help you solving it.

[soom-lupulus]

this problem maybe caused by the wrong deployed network.you should use '--network ' to specify the network you want to deploy when you deploying your smartcontract. For example, If you use hardhat network, must specify '--network localhost'. try it and hope you can get help from this.