Lesson 9: Unit Test "Massive Promise Test" assert winnerEndingBalance calculation

[wolf3i]

Patrick demonstrates that his code works:

assert.equal(
    winnerBalance.toString(), 
     startingBalance // startingBalance + ( (raffleEntranceFee * additionalEntrances) + raffleEntranceFee )
          .add(
              raffleEntranceFee
              .mul(additionalEntrances)
              .add(raffleEntranceFee)
         )
          .toString()

For me I get the error that my assert is not true:

 1) Raffle Unit Tests
       fullfillRandomWords
         picks a winner, resets the lottery, and sends money:

      AssertionError: expected '9999992425098394448651' to equal '9999992511672690899295'
      + expected - actual

      -9999992425098394448651
      +9999992511672690899295

The difference is 86.574.296.450.644 Wei which seems to me like there are Gas costs for entering the raffle and getting it payed out, which makes sense bc hardhat locoal node does have Gas costs enabled by default.

But it works for Patrick and nobody else seems to have this problem... Drives me crazy 😄

Also for me it is always the Deployer winning the lottery. That seems odd to me, does that make sense? Why would the Mock be set up to always let the first address win? Sounds like shitty test enviroment to me honestly...

[wolf3i]

Update (Still not solved tho):

I proofed my theory ( beeing really proud of myself :D):
Using this in the test.js results in a passing test, meaning that there are gas costs for the hardhat localnode and those where which let my test fail before.

const transactionResponse = await vrfCoordinatorV2Mock.fulfillRandomWords(
	txReceipt.events[1].args.requestId,
	raffle.address
)
const transactionReceipt = await transactionResponse.wait(1)
const { gasUsed, effectiveGasPrice } = transactionReceipt
const gasCost = gasUsed.mul(effectiveGasPrice)
console.log("gasCost: " + gasCost)

assert.equal(
	winnerEndingBalance.toString(),
	winnerStartingBalance
	.add(
		raffleEntranceFee.mul(additionalEntrants).add(raffleEntranceFee).sub(gasCost)
	)
	.toString()
)

But why do I seem to be the only one with this? I didnt change any settings where I would have manually enabled gascosts.
And also why is it always the Deployer as the first address to join the lottery to win? Why doesnt the mock has at least a basic randomiser to simulate the real thing better?

[bagariaraj23]

heyy @WolfgangNI can we connect? Even I'm facing the same problem, it's always the only one account which is winning the Raffle. Also I'm getting some similar assertion error, in the staging test.

[wolf3i]

I @bagariaraj23, yes I am glad that I'm not the only one :D I am also facing the issue with the gas costs with the staging test now... Trying to grab the gascost of the called funcitons but struggeling with that...
Do you know if I only have to take the gas costs of the raffle.enterRaffle() function in concideration or also the raffle.checkUpkeep(), raffle.performUpkeep() and raffle.fulfillRandomWords() ?
I'm trying to use callstatic to get the gascosts but am not sure if I should use that in the Promise body or underneath it...

What is your error message for the assertion error?

[wolf3i]

So the VRFCoordinatorV2Mock is supposed to always the return the same RandomWords (at least thats what ChatGPT said). why We get a different set of RandomWords than patrick tho idk... maybe there have been adjustments to the VRFCoordinatorV2Mock since he used it...

So with my staging test I found out that the difference of the EntranceFee to what the winner ends up getting back is two times the gas costs of the raffle.enterRaffle() function.
I guess that sending the amount back to the contestant using recentWinner.call{value: address(this).balance}("") is using the same amount of gas as the enterRaffle() transaction.
Now I would like to get the gas costs of this recentWinner.call{value: address(this).balance}("") transaction but using

let gasCostPayout
const txRpPayout = await raffle.callstatic.recentWinner()
const txRcPayout = await txRpPayout.wait(1)
{
	const { gasUsed, effectiveGasPrice } = await txRcPayout
	gasCostPayout = await gasUsed.mul(effectiveGasPrice)
}
console.log("gasCostFulfillRandomWords: " + gasCostPayout)

results in the error

TypeError: Cannot read properties of undefined (reading 'recentWinner')
      at FragmentRunningEvent.<anonymous> (test/staging/Raffle.staging.test.js:68:52)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)

I also tried using const txRpPayout = await raffle.callstatic.recentWinner.call("") which results in the same error.

any ideas?

[bagariaraj23]

uhh, Actually in my case earlier i was getting an assertion error as :

AssertionError: expected '384993087196025164' to equal '395027624697061289'
      + expected - actual

      -384993087196025164
      +395027624697061289

But I noticed that I wasn't wating for the transaction to complete hence i added the line

await tx.wait(2)

as in the following code snippet

 // Enter the raffle
                      console.log("Entering Raffle...")
                      await raffle.enterRaffle({ value: raffleEntranceFee })
                      await tx.wait(2)
                      console.log("Ok, time to wait...")
                      const winnerSTartingBalance = await accounts[0].getBalance()

But now I'm getting this new error

ReferenceError: Cannot access 'winnerSTartingBalance' before initialization

[wolf3i]

can you post your whole staging.test.js? I guess you call the winnerSTartingBalance after the promise body (which gets processed before the event fires).
Also note the winnerS T artingBalance might be a typo

[bagariaraj23]

yeah sure, I'm attaching my stagingTest.js

const { getNamedAccounts, deployments, ethers, network } = require("hardhat")
const { developmentChains, networkConfig } = require("../../helper-hardhat-config")
const { assert, expect } = require("chai")

developmentChains.includes(network.name)
    ? describe.skip
    : describe("Raffle Staging Tests", function () {
          let raffle, raffleEntranceFee, deployer

          beforeEach(async function () {
              deployer = (await getNamedAccounts()).deployer
              raffle = await ethers.getContract("Raffle", deployer)
              raffleEntranceFee = await raffle.getEntranceFee()
          })

          describe("fullfillRandomWords", function () {
              it("works with live Chainlink Keepers and Chainlink VRF, we get a random winner", async function () {
                  // enter the raffle
                  const startingTimeStamp = await raffle.getLatestTimeStamp()
                  const accounts = await ethers.getSigners()

                  await new Promise(async (resolve, reject) => {
                      // setup a listener before we enter the raffle
                      // just in case the blockchain moves really fast
                      raffle.once("WinnerPicked", async () => {
                          console.log("winner picked, event Fired")
                          try {
                              // add asserts here
                              const recentWinner = await raffle.getRecentWinner()
                              const raffleState = await raffle.getRaffleState()
                              const winnerEndingBalance = await accounts[0].getBalance()
                              const endingTimeStamp = await raffle.getLatestTimeStamp()

                              await expect(raffle.getPlayer(0)).to.be.reverted
                              assert.equal(recentWinner.toString(), accounts[0].address)
                              assert.equal(raffleState, 0)
                              assert.equal(
                                  winnerEndingBalance.toString(),
                                  winnerSTartingBalance.add(raffleEntranceFee).toString()
                              )
                              assert(endingTimeStamp.toString() > startingTimeStamp.toString())
                              resolve()
                          } catch (error) {
                              console.log(error)
                              reject(error)
                          }
                      })
                      // await raffle.enterRaffle({ value: raffleEntranceFee })
                      // Enter the raffle
                      console.log("Entering Raffle...")
                      await raffle.enterRaffle({ value: raffleEntranceFee })
                      await tx.wait(2)
                      console.log("Ok, time to wait...")
                      const winnerSTartingBalance = await accounts[0].getBalance()

                  })
              })
          })
      })

This is my complete staging test

Also There is no typo, i've by mistake written the capital winnerSTartingBalance everywhere, lol.

[bagariaraj23]

Also regarding the issue with only one address being the winner, In my case, I've completed the frontend part of the project and when i connect my metamask to the localhost testnet, and enter the raffle with the address(local hardhat address). I end up getting the winner as my own address, everytime. I don't know how to counter that issue.

I'm not sure about how the players are to be logged in to the Raffle, Do we need to connect with a new address and then enter the raffle again ? I tried doing this, but my whole raffle gets refreshed and the number of players is set back to 0 and then i am able to enter the raffle with only same connected address each time. Can you please help me out?

[wolf3i]

ok that is super weird, today I try to solve the gasCost issue and in the next days I might be able to catch up to you and try to figure it out

[bagariaraj23]

Yeah, if you get to know the reason behind this or come up with some logic, then please do help me with this

[alymurtazamemon]

@WolfgangNI I did not read some comments so maybe you found the answer but still, I am going to confirm your reason for why the winner is always the same.

This is because you are testing on Mocks and mocks always return the same result.

And for the number difference issue, I need to see your full code or if you are confirming that you did exactly the same then it might be possible that hardhat new versions change the behaviour of deducting the gas cost.

[bagariaraj23]

okay so in this case we can enter the raffle with 3 different accounts, right ??
1st being the deployer account

[alymurtazamemon]

@bagariaraj23 Here I have shown you the way you can connect and enter the raffle with different accounts. If you want multiple accounts to enter in the same test you can write a test like this;

it("records player when they enter", async () => {
    const [deployer, account2, account3] = await ethers.getSigners();

   const players = [deployer, account2, account3];
   for(let i = 0; i < players.length; i++) {
       await raffle.connect(players(i)).enterRaffle({ value: raffleEntranceFee });
    }
    do your testing...
})

[alymurtazamemon]

@bagariaraj23 I think you have not watched the complete lesson because Patrick showed the way you can enter multiple accounts into the raffle.

[bagariaraj23]

No, No i've watched the whole lesson but ig i still have a few doubts uncleared. Although thanks a lot for your help. I think i should rewatch some of the parts.

[wolf3i]

@alymurtazamemon
Hey Ali, I am still struggeling with my code... Now I have the same issue as @JovanniChen at Lesson 9: Staging test no result #4172
.
Everything looks fine when I look at the transactions between my wallet, the contract, the vrf and keepers, but the test never resolves...
I also tried patricks code from the repo but same thing...
(I definied the mocha timeout in hardhat.config.js to 300000ms, and waited up to 30 mins but not even the timeout kicks in...)

[wolf3i]

Hi @alymurtazamemon and @bagariaraj23,
pacelliv said that it might just be the testing enviroment that causes my issues, so i'll just move on with the course and hope i won't have this issue in Real Live

[bagariaraj23]

yeah okayy thanks a lot. Even i've moved on further