Im building a candle auction smart contract for my internship assignment, for getting complete random end time of the auction I'm using random number generator from chainlink.
However when executing the requestRandomEndTime function, I'm getting the error message as
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol"; import "@chainlink/contracts/src/v0.8/vrf/dev/VRFConsumerBaseV2Plus.sol"; import "@chainlink/contracts/src/v0.8/vrf/dev/libraries/VRFV2PlusClient.sol"; function startAuction(uint256 _itemId) public onlyOwner { require(items[_itemId].isListed, "Item not listed for auction"); require(auctions[_itemId].startTime == 0, "Auction already started for this item"); auctions[_itemId].startTime = block.number; requestRandomEndTime(_itemId); } function requestRandomEndTime(uint256 _itemId) public { uint256 requestId = s_vrfCoordinator.requestRandomWords( VRFV2PlusClient.RandomWordsRequest({ keyHash: keyHash, subId: s_subscriptionId, requestConfirmations: requestConfirmations, callbackGasLimit: callbackGasLimit, numWords: numWords, extraArgs: VRFV2PlusClient._argsToBytes(VRFV2PlusClient.ExtraArgsV1({nativePayment: false})) }) ); requestIdToItemId[requestId] = _itemId; } function fulfillRandomWords(uint256 requestId, uint256[] calldata randomWords) internal override { uint256 _itemId = requestIdToItemId[requestId]; uint randomBlocks = 20 + (randomWords[0] % 11); // 20 to 30 blocks auctions[_itemId].endTime = auctions[_itemId].startTime + randomBlocks; emit AuctionStarted(auctions[_itemId].endTime, items[_itemId].itemId, items[_itemId].itemName); } This is the deployed address of the contract: 0x784480bAf1aD4C0fE8523D6A4E1eB0304958998E on polygon Amoy. This is the error message I'm getting transact to CandleAuction.requestRandomEndTime errored: Error occurred: execution reverted.
execution reverted The transaction has been reverted to the initial state. Note: The called function should be payable if you send value and the value you send should be less than your current balance. You may want to cautiously increase the gas limit if the transaction went out of gas. This is the complete smart contact.
// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol"; import "@chainlink/contracts/src/v0.8/vrf/dev/VRFConsumerBaseV2Plus.sol"; import "@chainlink/contracts/src/v0.8/vrf/dev/libraries/VRFV2PlusClient.sol"; import "./candleAuctionNFT.sol"; contract CandleAuction is VRFConsumerBaseV2Plus, IERC721Receiver { struct ItemDetail { uint256 itemId; string itemName; string itemURI; bool isListed; } struct Auction { uint256 startTime; uint256 endTime; bool auctionEnded; address highestBidder; uint256 highestBid; mapping(address => uint256) bids; } NFT public nftContract; ItemDetail[] public items; mapping(uint256 => Auction) public auctions; mapping(uint256 => address) public itemWinners; mapping(uint256 => uint256) public requestIdToItemId; event ItemListed(uint256 itemId, string itemName, string itemURI); event AuctionStarted(uint256 endTime, uint256 itemId, string itemName); event HighestBidIncreased(address bidder, uint256 amount); event AuctionEnded(address winner, uint256 amount, uint256 itemId, string itemName); VRFCoordinatorV2Interface COORDINATOR; address vrfCoordinator; uint256 s_subscriptionId; bytes32 keyHash; uint32 callbackGasLimit; uint16 requestConfirmations; uint32 numWords; // Chainlink VRF variables // Chainlink VRF variables // VRFCoordinatorV2Interface COORDINATOR; // msg.sender // uint64 s_subscriptionId; // amoy = 4770084190029772705768595926798226884560589758950304855731850812408104746629 // address vrfCoordinator; // amoy = 0x7E10652Cb79Ba97bC1D0F38a1e8FaD8464a8a908 // bytes32 keyHash; // 0x3f631d5ec60a0ce16203bcd6aff7ffbc423e22e452786288e172d467354304c8 // uint32 callbackGasLimit; // 40000 // uint16 requestConfirmations; // 3 // uint32 numWords; // 1 // NFT Amoy Address: 0xa7526adcDc553Bb9588fAaB780c6d93C4Db39df4 // CandleAuction: 0x24f7403d2E3964D7f3041b81D11FBBc20ADbC945 constructor( address _vrfCoordinator, bytes32 _keyHash, uint256 _subscriptionId, uint32 _callbackGasLimit, uint16 _requestConfirmations, address _nftContract ) VRFConsumerBaseV2Plus(_vrfCoordinator) { vrfCoordinator = _vrfCoordinator; keyHash = _keyHash; s_subscriptionId = _subscriptionId; callbackGasLimit = _callbackGasLimit; requestConfirmations = _requestConfirmations; numWords = 1; COORDINATOR = VRFCoordinatorV2Interface(_vrfCoordinator); nftContract = NFT(_nftContract); } modifier onlyBeforeEnd(uint256 _itemId) { require(block.number < auctions[_itemId].endTime, "Auction already ended"); _; } modifier onlyAfterEnd(uint256 _itemId) { require(block.number >= auctions[_itemId].endTime, "Auction not yet ended"); _; } function listItem(string memory _itemName, string memory _itemURI) public onlyOwner { uint256 newItemId = nftContract.createNFT(address(this), _itemURI); items.push(ItemDetail({ itemId: newItemId, itemName: _itemName, itemURI: _itemURI, isListed: true })); emit ItemListed(newItemId, _itemName, _itemURI); } function startAuction(uint256 _itemId) public onlyOwner { require(items[_itemId].isListed, "Item not listed for auction"); require(auctions[_itemId].startTime == 0, "Auction already started for this item"); auctions[_itemId].startTime = block.number; requestRandomEndTime(_itemId); } function requestRandomEndTime(uint256 _itemId) /*internal*/ public { uint256 requestId = s_vrfCoordinator.requestRandomWords( VRFV2PlusClient.RandomWordsRequest({ keyHash: keyHash, subId: s_subscriptionId, requestConfirmations: requestConfirmations, callbackGasLimit: callbackGasLimit, numWords: numWords, extraArgs: VRFV2PlusClient._argsToBytes(VRFV2PlusClient.ExtraArgsV1({nativePayment: false})) }) ); requestIdToItemId[requestId] = _itemId; } function fulfillRandomWords(uint256 requestId, uint256[] calldata randomWords) internal override { uint256 _itemId = requestIdToItemId[requestId]; uint randomBlocks = 20 + (randomWords[0] % 11); // 20 to 30 blocks auctions[_itemId].endTime = auctions[_itemId].startTime + randomBlocks; emit AuctionStarted(auctions[_itemId].endTime, items[_itemId].itemId, items[_itemId].itemName); } function bid(uint256 _itemId) public payable onlyBeforeEnd(_itemId) { require(msg.value > auctions[_itemId].highestBid, "There already is a higher bid"); if (auctions[_itemId].highestBidder != address(0)) { auctions[_itemId].bids[auctions[_itemId].highestBidder] += auctions[_itemId].highestBid; } auctions[_itemId].highestBidder = msg.sender; auctions[_itemId].highestBid = msg.value; emit HighestBidIncreased(msg.sender, msg.value); } function withdraw(uint256 _itemId) internal returns (bool) { uint256 amount = auctions[_itemId].bids[msg.sender]; if (amount > 0) { auctions[_itemId].bids[msg.sender] = 0; if (!payable(msg.sender).send(amount)) { auctions[_itemId].bids[msg.sender] = amount; return false; } } return true; } function endAuction(uint256 _itemId) public onlyOwner onlyAfterEnd(_itemId) { require(!auctions[_itemId].auctionEnded, "Auction end has already been called for this item"); auctions[_itemId].auctionEnded = true; itemWinners[items[_itemId].itemId] = auctions[_itemId].highestBidder; emit AuctionEnded(auctions[_itemId].highestBidder, auctions[_itemId].highestBid, items[_itemId].itemId, items[_itemId].itemName); // Transfer the NFT to the winner nftContract.safeTransferFrom(address(this), auctions[_itemId].highestBidder, items[_itemId].itemId); // Transfer the highest bid amount to the owner payable(owner()).transfer(auctions[_itemId].highestBid); } function onERC721Received( address operator, address from, uint256 tokenId, bytes calldata data ) external override returns (bytes4) { // Implement your custom logic here return this.onERC721Received.selector; } } I don't know why I'm getting this error message, any help is deeply appreciated.
