VM Exception while processing transaction: reverted with an unrecognized custom error

[Mathenson]

THIS IS MY TEST FILE

//running the uint test on the develoment chain
const { assert, expect } = require("chai")
const { getNamedAccounts, deployments, ethers, network } = require("hardhat")
//const { isCallTrace } = require("hardhat/internal/hardhat-network/stack-traces/message-trace")
const { developmentChains, networkConfig } = require("../../helper-hardhat.config")

!developmentChains.includes(network.name)
? describe.skip
: describe("Lottery Uint Tests", async function () {
let lottery, vrfCoordinatorV2Mock, deployer, interval
const chainId = network.config.chainId

    beforeEach(async function () {

        deployer = (await getNamedAccounts()).deployer
        await deployments.fixture(["all"])
        lottery = await ethers.getContract("Lottery", deployer)
        vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock", deployer)
        lotteryEntranceFee = await lottery.getEntranceFee()
        interval = await lottery.getInterval()
    })
            //THIS IS FOR THE CONSTRUCTOR
    describe("constructor", async function () {
        it("initialize the lottery constructor correctly", async function () {

            const lotteryState = await lottery.getLotteryState()
            const interval = await lottery.getInterval()
            assert.equal(lotteryState.toString(), "0")
            assert.equal(interval.toString(), networkConfig[chainId]["interval"])
        })
        
    })
            //THIS IS FOR THE ENTER LOTTERY FUNCTION
    //testing for the enter raffle
    describe("enterLottery", async function () {
        //it revert error if enough eth is not inputed
        it("revert with a custom error Not enough ETH", async function () {
            await expect(lottery.enterLottery()).to.be.revertedWith(
                "Lottery__NotEnoughETHEntered"
            )
        })
        //it records player when the enter 
        it("it records the player as they enter", async function () {
              await lottery.enterLottery({value: lotteryEntranceFee })
              //make sure the deployer is recorded in the contract
              const playerFromContract = await lottery.getPlayer(0)
              assert.equal(playerFromContract, deployer)
        })

        //it emit an events when entered  
        it("it emit an evet when entered", async function () {
            await expect(lottery.enterLottery({value: lotteryEntranceFee})).to.emit(lottery,
                "lotteryEntered"
                )
        })
        //it doesnt allow players to enter when calculating
        //here we front run the block by using time travel to increatse
        //the block.timestamp so as to allow the lottery state to be in a
        //calculating state, which will reject entry from players
        it("reject entry during calculating period", async function (){
            await lottery.enterLottery({value: lotteryEntranceFee})
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
            //pretend to be a Chainlink keeper
            await lottery.performUpkeep([])
            await expect(lottery.enterLottery({ value: lotteryEntranceFee })).to.be.revertedWith(
                "Lottery__NotOpen"
                )
         })

    })
            //THIS IS FOR THE CHECKUPKEEP FUNCTION
    describe("checkUpKeep", async function () {
        it("returns false if people hasn't sent enough ETH", async function (){
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
            const { upkeepNeeded} = await lottery.callStatic.checkUpkeep([])
            assert(!upkeepNeeded)
        })
        //it return false if the raffle state is not open
        it("return false if the raffle isnt open", async function () {
            await lottery.enterLottery({value: lotteryEntranceFee})
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.request({method: "evm_mine", params:[] })
            await lottery.performUpkeep([])
            const lotteryState = await lottery.getLotteryState()
            const { upkeepNeeded } = await lottery.callStatic.checkUpkeep([])
            assert.equal(lotteryState.toString(), "1")
            assert.equal(upkeepNeeded, false)
        })
        //when the time hasn't passed
        it("return false if enough time hasnt passed", async function() {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            await network.provider.send("evm_increaseTime", [interval.toNumber() - 1])
            await network.provider.request({method: "evm_mine", params: []})
            const { upkeepNeeded} = await lottery.callStatic.checkUpkeep("0x")
            assert(!upkeepNeeded)
        })
       
        //when the time has passed
        it("return true if enough time has passed, has players, eth, and is open", async function () {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            await network.provider.send("evm_increaseTime", [interval.toNumber() - 1])
            await network.provider.request({method: "evm_mine", params: []})
            const { upkeepNeeded} = await lottery.callStatic.checkUpkeep("0x")
            assert(!upkeepNeeded)
        })
    })
    
})

THIS IS THE ERROR AM GETTING

1. Lottery Uint Tests
   enterLottery
   reject entry during calculating period:
   Error: VM Exception while processing transaction: reverted with an unrecognized custom error (return data: 0x71e83137)
   at . (0x5fbdb2315678afecb367f032d93f642f64180aa3)
   at Lottery.performUpkeep (contracts/Lottery.sol:141)
   at processTicksAndRejections (node:internal/process/task_queues:96:5)
   at runNextTicks (node:internal/process/task_queues:65:3)
   at listOnTimeout (node:internal/timers:528:9)
   at processTimers (node:internal/timers:502:7)
   at HardhatNode._mineBlockWithPendingTxs (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:1840:23)
   at HardhatNode.mineBlock (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:517:16)
   at EthModule._sendTransactionAndReturnHash (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:1532:18)

2. Lottery Uint Tests
   checkUpKeep
   return false if the raffle isnt open:
   Error: VM Exception while processing transaction: reverted with an unrecognized custom error (return data: 0x71e83137)
   at . (0x5fbdb2315678afecb367f032d93f642f64180aa3)
   at Lottery.performUpkeep (contracts/Lottery.sol:141)
   at processTicksAndRejections (node:internal/process/task_queues:96:5)
   at runNextTicks (node:internal/process/task_queues:65:3)
   at listOnTimeout (node:internal/timers:528:9)
   at processTimers (node:internal/timers:502:7)
   at HardhatNode._mineBlockWithPendingTxs (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:1840:23)
   at HardhatNode.mineBlock (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:517:16)
   at EthModule._sendTransactionAndReturnHash (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:1532:18)

[parishill25]

The problem is in your solidity file. share your solidity code

[Mathenson]

// what we wanna do
//Enter the lottery (paying some amount)
//Pick a random winner(verifiably random)
//Winner will be selected every X minutes ==> completly automated
//chainlink Oracles

//SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol";
import "@chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol";
import "@chainlink/contracts/src/v0.8/interfaces/KeeperCompatibleInterface.sol";

//errors
error Lottery__NotEnoughETHEntered();
error Lottery__TransferFailed();
error Lottery_NotOpen();
error Lottery__UpkeedNotNeeeded(uint256 currentBalance, uint256 numPlayers, uint256 raffleState);

/**

• @title A sample Lottery Contract
• @author Mathenson
• @notice This contract is for creating umtamperable decentralized smart contract
• @dev This implements chainlink VRF v2 and chainlink Keepers
  */

contract Lottery is VRFConsumerBaseV2, KeeperCompatibleInterface{

//Enum State declaration
enum LotteryState {
    OPEN,
    CALCUATING

}


        /*State Variables*/
//we will define an entrance fee for the lottery
uint256 private immutable i_entranceFee;
//we define an array of players
address payable[] private  s_players;
VRFCoordinatorV2Interface private immutable i_vrfCoordinator;
// this is amount of gas you are willing to pay
bytes32 private immutable i_gasLane; 
//the subscriptionID
uint64 private immutable i_subscriptionId; 

uint32 private immutable i_callbackGasLimit;
//how many confirmations the gas should wait before responding, 
//the more the node wait the more secure the random number is
uint16 private constant REQUEST_CONFIRMATIONS = 3; 
//how many radom words we want to request
uint32 private constant NUM_WORDS = 1;


        /*Events*/
event lotteryEntered(address indexed player);
event RequestedRaffleWinner(uint256 indexed requestId);
event WinnerPicked(address indexed winner );


        /* Lottery variables*/
address private s_recentWinner;
LotteryState private s_lotteryState;
uint256 private s_lastTimeStamp;
uint256 private i_interval;

        /* FUNCTIONS */
constructor(
    uint256 entranceFee, 
    address vrfCoordinatorV2, 
    bytes32 gasLane,
    uint64 subscriptionId,
    uint32 callbackGasLimit,
    uint256 interval
    ) VRFConsumerBaseV2(vrfCoordinatorV2){
    i_entranceFee = entranceFee;
    i_vrfCoordinator = VRFCoordinatorV2Interface(vrfCoordinatorV2);
    i_gasLane = gasLane;
    i_subscriptionId = subscriptionId;
    i_callbackGasLimit = callbackGasLimit;
    //initialise the raffle state as open
    s_lotteryState = LotteryState.OPEN; 
    s_lastTimeStamp = block.timestamp;
    i_interval =  interval;
}

//we wan to be able to enter raffle
function enterLottery()  public payable{
    if (msg.value < i_entranceFee) {
        revert Lottery__NotEnoughETHEntered();
    }
//should only allow player to enter if the lottery state is open
    if(s_lotteryState != LotteryState.OPEN) {
        revert Lottery_NotOpen();
    }
    s_players.push(payable(msg.sender)); 
    emit lotteryEntered(msg.sender);


/**
 * @dev  This is the function that the Chainlink nodes call
 * they look for the `UpKeepNeeded` to be return true
 * The following should be true in order to return true
 * 1. Our time interval should have passed
 * 2. the lottery should have at least 1 player, and have some ETH
 * 3. Our subscription is funded with LINK
 * 4. The lottery should be in an "open" state.
 */

}

function checkUpkeep(
    bytes memory /*checkData*/
    ) public view override returns (bool upKeepNeeded, bytes memory /*performData*/)
    {
        //check if the lottery state is open
        bool isOpen = (LotteryState.OPEN == s_lotteryState);
        //check if enough time has passed 
        bool timePassed = ((block.timestamp - s_lastTimeStamp) > i_interval);
        //check if we have enough players
        bool hasPlayers = (s_players.length > 0);
        //check if we have enough balance
        bool balanceOf = address(this).balance > 0;
        upKeepNeeded = (isOpen && timePassed && hasPlayers && balanceOf);

    }


//we shold be able to pick random winner
function performUpkeep(bytes calldata /*perfomData*/) external override{
    //we request random words
    //once we get it, we do something with it
    // 2 transaction process
    (bool upkeepNeeded, ) = checkUpkeep("");
    if(!upkeepNeeded) {
        revert Lottery__UpkeedNotNeeeded(address(this).balance, s_players.length, uint256 (s_lotteryState) );
    }
    s_lotteryState = LotteryState.CALCUATING;
    uint256 requestId =  i_vrfCoordinator.requestRandomWords(
        i_gasLane, //gas lane
        i_subscriptionId,
        REQUEST_CONFIRMATIONS,
        i_callbackGasLimit,
        NUM_WORDS
     );
     emit RequestedRaffleWinner(requestId);

}

function fulfillRandomWords(uint256 /*requestId*/, uint256[] memory randomWords) 
    internal 
    override {
        //using the modulo to get the winner randomly
        uint256 indexOfWinner = randomWords[0] % s_players.length;
        address payable recentWinner = s_players[indexOfWinner];
        s_recentWinner = recentWinner;
        s_lotteryState = LotteryState.OPEN;
        //reset players array
        s_players = new address payable[](0);
        //reset timestamp
        s_lastTimeStamp = block.timestamp;
        (bool success, ) = recentWinner.call{value: address(this).balance}("");
        if(!success){
            revert Lottery__TransferFailed();
        }
        //query the list of winners
        emit WinnerPicked(recentWinner);
         

    }
        /*View / Pure functions */

//show entrance fee
function getEntranceFee() public view returns (uint256) {
    return i_entranceFee;
}

//get players
function getPlayer(uint256 index) public view returns(address) {
    return s_players[index];
}

//get recent winner
function getRecentWinners() public view returns(address) {
    return s_recentWinner;
}

//get raffle state
function getLotteryState() public view returns (LotteryState) {
    return s_lotteryState;
}

//get number of random words
function getNumWords() public pure returns(uint256) {
    return NUM_WORDS;
}

//get number of players
function getPlayerNums() public view returns(uint256) {
    return s_players.length;
}

//get tmestamp
function getLatestTimestamp() public view returns(uint256){
    return s_lastTimeStamp;
}

//get blockconformation
function getRequestConfirmatons() public pure returns(uint256) {
    return REQUEST_CONFIRMATIONS;
}

//get the interval
function getInterval() public  view returns (uint256) {
    return i_interval;
}

}

[Mathenson]

please that is my solidity file......how can you help me

[HarshDev56]

@Mathenson in your test you add double _ in expected error like this
"Lottery__NotOpen"

and in your solidity contract it has single _ like this
Lottery_NotOpen()

so replcae this

it("reject entry during calculating period", async function (){
           await lottery.enterLottery({value: lotteryEntranceFee})
           await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
           await network.provider.send("evm_mine", [])
           //pretend to be a Chainlink keeper
           await lottery.performUpkeep([])
           await expect(lottery.enterLottery({ value: lotteryEntranceFee })).to.be.revertedWith(
               "Lottery__NotOpen"
               )
        })

to this

 it("reject entry during calculating period", async function (){
            await lottery.enterLottery({value: lotteryEntranceFee})
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
            //pretend to be a Chainlink keeper
            await lottery.performUpkeep([])
            await expect(lottery.enterLottery({ value: lotteryEntranceFee })).to.be.revertedWith(
                "Lottery_NotOpen"
                )
         })

[Mathenson]

thanks have corrected that but that doesnt seems to fix the problem am getting another vm error

Error: VM Exception while processing transaction: reverted with custom error 'InvalidConsumer()'
at VRFCoordinatorV2Mock.onlyValidConsumer (@chainlink/contracts/src/v0.8/mocks/VRFCoordinatorV2Mock.sol:72)
at VRFCoordinatorV2Mock.requestRandomWords (@chainlink/contracts/src/v0.8/mocks/VRFCoordinatorV2Mock.sol:147)
at Lottery.performUpkeep (contracts/Lottery.sol:141)
at processTicksAndRejections (node:internal/process/task_queues:96:5)
at runNextTicks (node:internal/process/task_queues:65:3)
at listOnTimeout (node:internal/timers:528:9)
at processTimers (node:internal/timers:502:7)
at HardhatNode._mineBlockWithPendingTxs (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:1840:23)
at HardhatNode.mineBlock (node_modules/hardhat/src/internal/hardhat-network/provider/node.ts:517:16)
at EthModule._sendTransactionAndReturnHash (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:1532:18)

[HarshDev56]

@Mathenson run npm install --save-dev @chainlink/contracts@0.4.1

[Mathenson]

have done that before sir....I had issues with AutomationCompatibleInterface which is missing in the version
so I have to restore the default chainlink version which has KeeperCompatibleInterface
I am so stuck😥😥

[HarshDev56]

@Mathenson share your repo link i will check .

[Mathenson]

https://github.com/Mathenson/Lottery-Sepolia/blob/master/test/unit/Lottery.test.js

thanks you can PR please if you've figure out the problem

[HarshDev56]

@Mathenson first you have to run yarn add --dev @chainlink/contracts@0.4.1 then your problem is solved. and your code also have other 10-11 issue which i solved and add comment with "ERRORCODE:" and one more thing @Mathenson don't mix package managers like if you use yarn then use only yarn and if you use npm then use only npm in single project .
if you find this solution helpful please mark it as solution/Answer so others can know that this issue is solved . and also help full for others .😊

`
//running the uint test on the develoment chain
const { assert, expect } = require("chai")
const { getNamedAccounts, deployments, ethers, network } = require("hardhat")
//const { isCallTrace } = require("hardhat/internal/hardhat-network/stack-traces/message-trace")
const { developmentChains, networkConfig } = require("../../helper-hardhat.config")

!developmentChains.includes(network.name)
? describe.skip
: describe("Lottery Uint Tests", async function () {
let lottery, lotteryContract, vrfCoordinatorV2Mock, deployer, interval
const chainId = network.config.chainId

    beforeEach(async function () {

        deployer = (await getNamedAccounts()).deployer
        await deployments.fixture(["all"])
        lottery = await ethers.getContract("Lottery", deployer)
        lotteryContract = await ethers.getContract("Lottery")
        vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock", deployer)
        lotteryEntranceFee = await lottery.getEntranceFee()
        interval = await lottery.getInterval()
        accounts = await ethers.getSigners()
    })
            //THIS BLOCK IS FOR THE CONSTRUCTOR
    describe("constructor", async function () {
        it("initialize the lottery constructor correctly", async function () {

            const lotteryState = await lottery.getLotteryState()
            const interval = await lottery.getInterval()
            assert.equal(lotteryState.toString(), "0")
            assert.equal(interval.toString(), networkConfig[chainId]["interval"])
        })
        
    })
            //THIS BLOCK IS FOR THE ENTER LOTTERY FUNCTION
    //testing for the enter raffle
    describe("enterLottery", async function () {
        //it revert error if enough eth is not inputed
        it("revert with a custom error Not enough ETH", async function () {
            await expect(lottery.enterLottery()).to.be.revertedWith(
                "Lottery__NotEnoughETHEntered"
            )
        })
        //it records player when the enter 
        it("it records the player as they enter", async function () {
              await lottery.enterLottery({value: lotteryEntranceFee })
              //make sure the deployer is recorded in the contract
              const playerFromContract = await lottery.getPlayer(0)
              assert.equal(playerFromContract, deployer)
        })

        //it emit an events when entered  
        it("it emit an evet when entered", async function () {
            await expect(lottery.enterLottery({value: lotteryEntranceFee})).to.emit(lottery,
                "lotteryEntered"
                )
        })
        //it doesnt allow players to enter when calculating
        //here we front run the block by using time travel to increatse
        //the block.timestamp so as to allow the lottery state to be in a
        //calculating state, which will reject entry from players
        it("reject entry during calculating period", async function (){
            await lottery.enterLottery({value: lotteryEntranceFee})
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
            //pretend to be a Chainlink keeper
            await lottery.performUpkeep([])
            await expect(lottery.enterLottery({ value: lotteryEntranceFee })).to.be.revertedWith(
                "Lottery__NotOpen"
                )
         })

    })
            //THIS BLOCK IS FOR THE CHECKUPKEEP FUNCTION
    describe("checkUpKeep", async function () {
        it("returns false if people hasn't sent enough ETH", async function (){
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
            const { upkeepNeeded} = await lottery.callStatic.checkUpkeep([])
            assert(!upkeepNeeded)
        })
        //it return false if the raffle state is not open
        it("return false if the raffle isnt open", async function () {
            await lottery.enterLottery({value: lotteryEntranceFee})
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            // await network.provider.request({method: "evm_mine", params:[] }) // ERRORCODE: below line is correct
            await network.provider.send("evm_mine", []) // ERRORCODE: correct line above line 
            await lottery.performUpkeep([])
            const lotteryState = await lottery.getLotteryState()
            console.log("lottery "+lottery);
            console.log("await lottery.callStatic.checkUpkeep([]) "+await lottery.callStatic.checkUpkeep([]));
            const { upKeepNeeded } = await lottery.callStatic.checkUpkeep([]) // ERRORCODE: here you name wroung upKeepNeeded you should give give same name as give in contract file
            assert.equal(lotteryState.toString(), "1")
            assert.equal(upKeepNeeded, false)
        })
        //when the time hasn't passed
        it("return false if enough time hasnt passed", async function() {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            await network.provider.send("evm_increaseTime", [interval.toNumber() - 1])
            await network.provider.request({method: "evm_mine", params: []})
            const { upkeepNeeded} = await lottery.callStatic.checkUpkeep("0x")
            assert(!upkeepNeeded)
        })
       
        //when the time has passed
        it("return true if enough time has passed, has players, eth, and is open", async function () {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            await network.provider.send("evm_increaseTime", [interval.toNumber() - 1])
            await network.provider.request({method: "evm_mine", params: []})
            const { upkeepNeeded} = await lottery.callStatic.checkUpkeep("0x")
            assert(!upkeepNeeded)
        })
    })
            //THIS BLOCK IS FOR THE PERFORM UPKEEP
    describe("performUpkeep", function () {
        it("it can only run if checkupkeep is true", async function () {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
            const tx = await lottery.performUpkeep([])
            assert(tx)
        })
        it("revert if checkupkeep is false", async function () {
            await expect(lottery.performUpkeep([])).to.be.revertedWith(
                "Lottery__UpkeedNotNeeeded"
            )
        })
        it("updates the raffle state, emits and event, and calls the vrf coordinator", async function () {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            //increase block.timestamp
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            //mine the block 
            await network.provider.send("evm_mine", [])
            const txResponse = await lottery.performUpkeep([])
            const txReceipt = await txResponse.wait(1)
            const requestId = txReceipt.events[1].args.requestId
            const lotteryState = await lottery.getLotteryState()
            assert(requestId.toNumber() > 0)
            assert(lotteryState.toString() == "1") // ERRORCODE: here toString() is correct method to call rather then toNumber()
        })
    })

            //THIS BLOCK IS FOR FULFILL RANDOMWORDS
    describe("fulfillrandomwords", async function () {
        beforeEach(async function () {
            await lottery.enterLottery({ value: lotteryEntranceFee })
            await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
            await network.provider.send("evm_mine", [])
        })
        it("can only be called after performUpkeep", async function () {
             await expect(vrfCoordinatorV2Mock.fulfillRandomWords(0, lottery.address)
                ).to.be.revertedWith("nonexistent request")
            await expect(vrfCoordinatorV2Mock.fulfillRandomWords(1, lottery.address)
            ).to.be.revertedWith("nonexistent request")
        })
        it("picks a winner, reset the lottery, and send money", async function () {
            const additionalEntrances = 3 // to test
            const startingIndex = 2
            for (let i = startingIndex; i < startingIndex + additionalEntrances; i++) { // i = 2; i < 5; i=i+1
                lottery = lotteryContract.connect(accounts[i]) // Returns a new instance of the Raffle contract connected to player
                await lottery.enterLottery({ value: lotteryEntranceFee })
            } //{
                // const accountConnectLottery = lottery.connect(accounts[i])
                // await accountConnectLottery.enterLottery({ value: lotteryEntranceFee }) 
           // }
            const startingTimeStamp = await lottery.getLatestTimeStamp()

            //performUpkeep (mock being chainlink keepers)
            //fulfillRandomwords (mock being the chainlink VRF)
            //we will have to wait for the fullfilrandomword to be called
            await new Promise(async (resolve, reject ) => {
                lottery.once("WinnerPicked", async () => {
                    console.log("Found the event")
                    try {
                         const recentWinner = await lottery.getRecentWinners() // ERRORCODE: this line should be here not  down there also ERRORCODE: method name in contract is getRecentWinners 
                        console.log(recentWinner)
                        console.log(accounts[2]) // ERRORCODE: here there is accounts not account
                        console.log(accounts[0]) // ERRORCODE: here there is accounts not account
                        console.log(accounts[1]) // ERRORCODE: here there is accounts not account
                        console.log(accounts[3]) // ERRORCODE: here there is accounts not account
                       
                        const lotteryState = await lottery.getLotteryState()
                        const endingTimeStamp = await lottery.getLatestTimeStamp()
                        const numPlayers = await lottery.getPlayerNums() // ERRORCODE: method name in contract is getRecentWinners 
                        assert.equal(numPlayers.toString(), "0")
                        assert.equal(lotteryState.toString(), "0")
                        assert(endingTimeStamp > startingTimeStamp)
                    } catch (e) {
                        reject(e)
                    }
                    resolve()
                })
                //seeting up a listener
                //we will fire an even, and the listener will pick it up and resolve
                const tx = await lottery.performUpkeep([1])
                const txReceipt = await tx.wait(1)
                await vrfCoordinatorV2Mock.fulfillRandomWords(
                    txReceipt.events[1].args.requestId,
                    lottery.address
                )
               
            })

        })
    })
})

`