Lesson 9: Unable to retrieve requestId

[harshuo2]

it("tests if raffle is CALCULATING, emits an event, and calls the vrf coordinator", async function () {
          await raffle.enterRaffle({ value: entryFee })
          await network.provider.send("evm_increaseTime", [
            raffleInterval.toNumber() + 1,
          ])
          await network.provider.send("evm_mine", [])
          const txResponse = await raffle.performUpkeep([])
          const txReceipt = await txResponse.wait(1)
          const requestId = await txReceipt.events[1].args.requestId // upar ka func emits an event
          raffleState = await raffle.getRaffleState()
          assert.equal(raffleState.toString(), "1")
          //assert(requestId > 0)
          expect(requestId.toString()).to.be.greaterThan("0")
        })

Unable to retrieve requestId from the above code. I'm getting the following error:

1) Raffle Unit Tests
       performUpkeep
         tests if raffle is CALCULATING, emits an event, and calls the vrf coordinator:
     TypeError: Cannot read properties of undefined (reading 'toString')
      at Context.<anonymous> (test/unit/Raffle.test.js:130:28)



error Command failed with exit code 1.

My performUpkeep function is like this:

function performUpkeep(
    bytes calldata /* performData */
  ) external override {
    // we made this function to be external because we wont call it from inside our function, and overall external fun are cheaper
    // pick a Random Winner
    // do something with it
    // 2 transaction process
    (bool upkeepNeeded, ) = checkUpkeep(""); // "" because we dont want to pass anything in the calldata of checkupkeep
    if (!upkeepNeeded) {
      revert Raffle__UpkeepNotNeeded(
        address(this).balance,
        s_players.length,
        uint256(s_raffleState)
      );
    }
    s_raffleState = RaffleState.CALCULATING;
    uint256 requestId = i_vrfCoordinator.requestRandomWords(
      i_keyHash,
      i_subscriptionId,
      REQUEST_CONFIRMATIONS,
      i_callbackGasLimit,
      NUM_WORDS
    ); // this will return a uint256 which we can store
    emit RequestedRaffleWinner(requestId);
  }

[DorianDaSilva]

Try commenting out these lines one at a time to identify if the issue comes from here:
assert.equal(raffleState.toString(), "1") or expect(requestId.toString()).to.be.greaterThan("0")

Also, you may want to try to use const on raffleState = await raffle.getRaffleState() to define raffleState as the error says one of your variables .toString is undefined.

[harshuo2]

that one error is in the requestId. I am unable to define it for the time being... The error is with these lines of code

const txResponse = await raffle.performUpkeep([])
          const txReceipt = await txResponse.wait(1)
          const requestId = await txReceipt.events[1].args[0].requestId

[shaunsaker]

In my case, to get the requestId I had to do txReceipt.events[1].args[0]. Hopefully that helps you 🙂

[harshuo2]

Wow thanks!! That totally worked out. But can you tell me how you got to this solution?

[shaunsaker]

Glad it worked! I just console.log'd txReceipt, events etc until I found the requestId.

[harshuo2]

Wow thanks for that... Can you help me understand more about events by directing me to some resources?

[shaunsaker]

Sure thing. There is an additional video in the course resources that I'd recommend going through. It has a coding exercise which better solidified events for me.