Lesson 7: FundMe.test.js "Error: call revert exception"

[eerjuano]

Hi another time.
Context: I've followed the video's creation of FundMe.test.js until 11:30. I've installed all dependencies and deployed all the stuffs fine, but when i run the test it returns an uncommon error. I followed the instructions, but I think I've done something wrong too earlier. When I look at the questions I don't find someone with the same error. I have stuck for a week in this error and I can't find the solution.
Here is the consolelog:

  FundMe
    constructor
      1) sets the aggregator addresses correctly
    fund
      ✔ Didn't send enough


  1 passing (973ms)
  1 failing

  1) FundMe
       constructor
         sets the aggregator addresses correctly:
     Error: call revert exception [ See: https://links.ethers.org/v5-errors-CALL_EXCEPTION ] (method="priceFeed()", data="0x", errorArgs=null, errorName=null, errorSignature=null, reason=null, code=CALL_EXCEPTION, version=abi/5.6.4)
      at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:261:28)
      at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:273:20)
      at Interface.decodeFunctionResult (node_modules/@ethersproject/abi/src.ts/interface.ts:427:23)
      at Contract.<anonymous> (node_modules/@ethersproject/contracts/src.ts/index.ts:400:44)
      at step (node_modules/@ethersproject/contracts/lib/index.js:48:23)
      at Object.next (node_modules/@ethersproject/contracts/lib/index.js:29:53)
      at fulfilled (node_modules/@ethersproject/contracts/lib/index.js:20:58)



error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

FundMe.test.js:

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

describe("FundMe", async function () {
    let fundMe
    let deployer
    let mockV3Aggregator
    const sendValue = ethers.utils.parseEther("1") // that converts the 1 to the amount of ether
    beforeEach(async () => {
        // deploy our fundMe contract
        // using Hardhat-deploy
        // const accounts = await ethers.getSigners()
        // const accountZero = accounts[0]
       const {deployer} = await getNamedAccounts(); //this catch the deployer object and signed on deployer
        await deployments.fixture(["all"]) //fixture from hardhat allows us to acces all tags of the folders and files
        fundMe = await ethers.getContractAt("FundMe", deployer) //now, fundMe variable would be equal to the contract FundMe
        mockV3Aggregator = await ethers.getContractAt(
            "MockV3Aggregator",
            deployer
        )
        providers.getCode
    })

    describe("constructor", async function () {
        it("sets the aggregator addresses correctly", async function () {
            const response = await fundMe.priceFeed() //this will run locally the priceFeed variable of the smartcontract
            assert.equal(response, mockV3Aggregator.address)
        })
    })

    describe("fund", async function (){
        it("Didn't send enough", async function(){
            await fundMe.fund()
        })
    })
})

FundMe.sol:

// SPDX-License-Identifier: MIT
// Pragma
pragma solidity ^0.8.7;
// Imports
import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
import "./PriceConverter.sol";
// Error Codes
error FundMe__NotOwner();

//Interfaces, Libraries, Contracts
/** @title A contract for crowd funding
 *  @author BeastDevMoney
 *  @notice This contract is to demo a samle funding contract
 *  @dev This implements price feeds as our library
 */
contract FundMe {
    //Type Declarations
    using PriceConverter for uint256;

    //State Variables
    mapping(address => uint256) public addressToAmountFunded;
    address[] public funders;
    address public immutable owner;
    uint256 public constant minimumUSD = 50 * 1e18; //constant variables are cheaper when it is called than normal variables

    AggregatorV3Interface public priceFeed;

    modifier onlyOwner() {
        //require(msg.sender == owner);
        if (msg.sender != owner) revert FundMe__NotOwner();
        _;
    }

    //Functions Order:
    //// constructor
    //// receive
    //// fallback
    //// external
    //// public
    //// internal
    //// private
    //// view / pure

    constructor(address priceFeedAddress) {
        owner = msg.sender;
        priceFeed = AggregatorV3Interface(priceFeedAddress);
    }

    /**
     *  @notice This function funds this contract
     *  @dev This implements price feeds as our library
    here you can put "paramaters" and "returns" if it has the function
     */
    function fund() public payable {
        require( //the first parameter it goint to be msg.value and the second paramater it's going to be priceFeed
            msg.value.getConversionRate(priceFeed) >= minimumUSD,
            "Didn't send enough!"
        );
        funders.push(msg.sender);
        addressToAmountFunded[msg.sender] = msg.value;
    }

    function withdraw() public onlyOwner {
        for (
            uint256 funderIndex = 0;
            funderIndex < funders.length;
            funderIndex++
        ) {
            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }

        funders = new address[](0);

        //transfer
        //msg.sender = address
        //payable(msg.sender) = payable address
        //call
        (bool callSucces, ) = payable(msg.sender).call{
            value: address(this).balance
        }("");
        require(callSucces, "Call failed");
        //this it refers to the hole contract
    }
}

I don't know if its something simple, but I don't understand whats going on.

[krakxn]

Following along with the following should fix your issue

1. In FundMe.test.js, copy the following code:

describe("constructor", async function () {
        it("sets the aggregator addresses correctly", async function () {
            const response = await fundMe.getPriceFeed() //this will run locally the priceFeed variable of the smartcontract
            assert.equal(response, mockV3Aggregator.address)
        })
    })

Also, is the following code correct? I have not seen this being used, make sure it is — if not, please remove it.

providers.getCode

2. In FundMe.sol, add the following code at last:

function getPriceFeed() public view returns (AggregatorV3Interface) {
        return priceFeed;
    }

[eerjuano]

I've tried copypasting the code and it's returning the same error. Where I have to put the providrs.getCode? And for what is it?

[krakxn]

Yeah, I am unsure too because I never saw it being used for this course. You should just not use it (unless Patrick tells you to and I do not remember)

[adityabhattad2021]

In test please replace this:

           mockV3Aggregator = await ethers.getContractAt(
            "MockV3Aggregator",
            deployer
        )

by this

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

and here

 describe("constructor", async function () {
        it("sets the aggregator addresses correctly", async function () {
            const response = await fundMe.priceFeed() //this will run locally the priceFeed variable of the smartcontract
            assert.equal(response, mockV3Aggregator.address)
        })
    })

try logging response and mockV3Aggregator.address
to see what is the problem.

[alymurtazamemon]

@eerjuano Push the code to GitHub and leave link here, need to fix issues.

[alymurtazamemon]

@eerjuano working on it right now

[alymurtazamemon]

@eerjuano These were the issues:

1. The main one, your ETH/USD address was incorrect.
2. deployer = (await getNamedAccounts()).deployer here you need to wait for accounts and then get the deployer from it.
3. Your code also has conflicts of dependencies issues.

Now it is working and going to push it to your repo.

[adityabhattad2021]

Really this is the hardest thing to find "Your code also has conflicts of dependencies issues", I was myself stuck with this for a whole day.
@alymurtazamemon @krakxn You guys are really doing an awesome job!

[krakxn]

@adityabhattad2021 No problem.

In the future, always fix the dependencies first—they are in most cases conflicts w/ the packages—and going through the entire codebase wastes a lot of time.

[eerjuano]

Thanks so much, you're awesome. You're knowledge and experience are incredible. Another time, thanks.

[othaime-en]

Hey @eerjuano write your beforeEach like this:

1. remove provider.getCode it is unnecessary in this context
2. Use ethers.getContract() not ethers.getContractAt()
3. rewrite const {deployer} = await getNamedAcccounts(); no need to use const, you've already initialized deployer variable above.

    beforeEach(async () => {
        // deploy our fundMe contract
        // using Hardhat-deploy
        // const accounts = await ethers.getSigners()
        // const accountZero = accounts[0]
       deployer = (await getNamedAccounts()).deployer; //this catch the deployer object and signed on deployer
       await deployments.fixture(["all"]) //fixture from hardhat allows us to acces all tags of the folders and files
       fundMe = await ethers.getContract("FundMe", deployer) //now, fundMe variable would be equal to the contract FundMe
       mockV3Aggregator = await ethers.getContract(
            "MockV3Aggregator",
            deployer
        )
    })

This might solve some of your errors

[othaime-en]

It is also advised you create a getter function for your priceFeed. Add this at the bottom of you FundMe contract in FundMe.sol

function getPriceFeed() public view returns (AggregatorV3Interface) {
        return priceFeed;
  }