Lesson 9: fulfillRandomWords unit testing time out

[CanonicalJP]

Hello, I've been struggling to understand why the event "WinnerPicked" is never triggered when testing in hardhat. I've tried some debugging and seems like vrfCoordinatorV2Mock.fulfillRandomWords never finishes here:

await vrfCoordinatorV2Mock.fulfillRandomWords(
                          txReceipt.events[1].args.requestId,
                          raffle.address
                      )

I've tried forcing the event myself but it only works if I do it before vrfCoordinatorV2Mock.fulfillRandomWords. Plus, I also tried importing Raffle.test.js and Raffle.sol from the repo but same result. Thus, not sure exactly where is the issue that is blocking fulfillRandomWords from emiting the event.

I'd really appreciate some help on this.

Section from Raffle.test.js below and my repo is @0xJayPi/hardhat-smartcontract-lottery

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

!developmentChains.includes(network.name)
    ? describe.skip
    : describe("Raffle Unit Test", function () {
          let raffle, vrfCoordinatorV2Mock, raffleEntranceFee, deployer, interval
          const chainId = network.config.chainId

          beforeEach(async function () {
              await deployments.fixture(["all"])
              deployer = (await getNamedAccounts()).deployer
              raffle = await ethers.getContract("Raffle", deployer)
              vrfCoordinatorV2Mock = await ethers.getContract("VRFCoordinatorV2Mock")
              raffleEntranceFee = await raffle.getEntranceFee()
              interval = await raffle.getInterval()
          })

          describe("fulfillRandomWords", function () {
              beforeEach(async function () {
                  await raffle.enterRaffle({ value: raffleEntranceFee })
                  await network.provider.send("evm_increaseTime", [interval.toNumber() + 1])
                  await network.provider.send("evm_mine", [])
              })

              it("Can only be called after perfomrUpkeep", async function () {
                  await expect(
                      vrfCoordinatorV2Mock.fulfillRandomWords(0, raffle.address)
                  ).to.be.revertedWith("nonexistent request")
                  await expect(
                      vrfCoordinatorV2Mock.fulfillRandomWords(1, raffle.address)
                  ).to.be.revertedWith("nonexistent request")
              })

              it("Picks a winner, resets the lottery, and sends the money", async function () {
                  const additionalEntrances = 3
                  const startingAccountIndex = 1 // deployer = 0
                  const accounts = await ethers.getSigners()
                  for (
                      let i = startingAccountIndex;
                      i < startingAccountIndex + additionalEntrances;
                      i++
                  ) {
                      const accountConnectedRaffle = raffle.connect(accounts[i])
                      await accountConnectedRaffle.enterRaffle({ value: raffleEntranceFee })
                  }
                  const startingTimeStamp = await raffle.getLatestTimeStamp()

                  await new Promise(async (resolve, reject) => {
                      /* Events Listener */
                      raffle.once("WinnerPicked", async () => {
                          console.log("Found the event!")
                          try {
                              const recentWinner = await raffle.getRecentWinner()
                              console.log(recentWinner)
                              console.log(accounts[0].address)
                              console.log(accounts[1].address)
                              console.log(accounts[2].address)
                              console.log(accounts[3].address)
                              const raffleState = await raffle.getRaffleState()
                              const endingTimeStamp = await raffle.getLatestTimeStamp()
                              const numPlayers = await raffle.getNumberOfPlayers()
                              assert.equal(raffleState.toString(), "0")
                              assert.equal(numPlayers.toString(), "0")
                              assert(endingTimeStamp > startingTimeStamp)
                              resolve()
                          } catch (e) {
                              reject(e)
                          }
                      })

                      const txResponse = await raffle.performUpkeep([])
                      const txReceipt = await txResponse.wait(1)

                      await vrfCoordinatorV2Mock.fulfillRandomWords(
                          txReceipt.events[1].args.requestId,
                          raffle.address
                      )
                      raffle.emit("WinnerPicked") // this is a test to force the event
                  })
              })
          })
      })

[alymurtazamemon]

@0xJayPi console log this txReceipt and show me.

[alymurtazamemon]

@0xJayPi when we debug it togather we found that there is no object that contain requestId anymore, instead we found an array that contain a big value and when we convert it to string, we found that it is a requestId but in value.

[CanonicalJP]

Got you, and since it was the only value returned by the RequestedRaffleWinner event in the perfomUpkeep() function, it had to be requestId.

Thanks a lot, man!!

[AshishLach]

Hi @alymurtazamemon,

Can you please me here, I am facing the same issue but am not able to resolve it. I am trying to run tests in local network. "WinnerPicked" event is not getting triggered.

Here is the screenshot

GitHub link
https://github.com/ashishlac/Hardhat-raffle-me-fcc

command
hh test --grep "picks a winner"

[deep0072]

same issue i am facing rn

[AshishLach]

same issue i am facing rn

Hi @deep0072,

Please check the suggested approach here.
https://github.com/smartcontractkit/full-blockchain-solidity-course-js/discussions/3569