Lesson 9: Raffle Lottery -Last Unit test case Timeouterror. fulfillRandomWords function not triggering event "WinnerPicked"

[AshishLach]

Hi Everyone,

Can someone help me here, I am facing a timeout issue when the below function is called. Seems like the WinnerPicked event is not getting raised.

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

After reading other posts I did below but that didn't resolve it

1. I increased the timeout to 500secs or 1000secs but still same timeout issue.
2. I created a new subscription id, but i don't think this could be the issue because we are doing unit testing which does the testing in the local network and for local network we are creating mocks and new subscriptions programmatically.
3. Reverified all my code and even copy-pasted the entire code(Raffle.sol and Raffle.test.js) from Pattrick Github but still this didn't resolve it.
4. Verified all constructor parameters of the mock contract, all parameters are passing corrected and with the correct order.

From txReceipt, we are receiving RequestId value as 1. Here is the response of txReceipt.events[1].args

  BigNumber { _hex: '0x01', _isBigNumber: true },
  requestId: BigNumber { _hex: '0x01', _isBigNumber: true }
]

Here is the command I am running

hh test --grep "picks a winner"

Here is the github link where i uploaded project files
https://github.com/ashishlac/Hardhat-raffle-me-fcc

Here is the screenshot

Adding more info here: I am about to complete the next lesson (Lesson 10: Nextjs full stack) and executed below command to mock the Raffle winner

hh run scripts/mockOffChain.js --network localhost
Performed upkeep with RequestId: 1
We on a local network? Ok let's pretend...
Responded!
The winner is: 0x0000000000000000000000000000000000000000

but I am receiving the winner as "0x0000000000000000000000000000000000000000" always which I am guessing the fulfillRandomWords() override function in my Raffle contract is not even executing. Please help.

[AshishLach]

Hi Everyone,

Please ignore the above question. I have resolved it just now.

I kept callbackGasLimit very low inside helper hardhat config js. It's working fine after we increase the limit.
Based on the documentation if we don't keep enough callbackGaslimit, the callback function will fail.

Current one:
callbackGasLimit: "50000",

Changed to 
callbackGasLimit: "500000",

If someone facing these issues, I will suggest you try to figure out what went wrong by yourself first by following these steps

1. • Clone the entire project from Pattric GitHub and test it out.
2. • If the cloned project is working fine, then something we might have missed in our project.
3. • Copy and Paste each file into your local project and run the test command. One file at a time.
4. • When that specific test is successful, Compare that recently copied file with your older version.
5. • If the issue is still not resolved check the module versions with the cloned project.
6. The difference in versions of WebKit, Moralis and other modules gave me a lot of headaches recently.