VRF 2.5 (#1917)

* VRF 2.5

Co-authored-by: Karim H. <[email protected]>
Co-authored-by: Dwight Lyle <[email protected]>
Co-authored-by: Crystal Gomes <[email protected]>

* Empty commit to bump builds

* Migration page - minor corrections

* Add release note

* Address more review comments and fix a link

---------

Co-authored-by: thedriftofwords <[email protected]>
Co-authored-by: Karim H. <[email protected]>
Co-authored-by: Crystal Gomes <[email protected]>

Author: 3 people

public/samples/VRF/v2-5/DirectFundingConsumer.sol

@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: MIT
+// An example of a consumer contract that directly pays for each request.
+pragma solidity 0.8.19;
+
+import {ConfirmedOwner} from "@chainlink/contracts/src/v0.8/shared/access/ConfirmedOwner.sol";
+import {LinkTokenInterface} from "@chainlink/contracts/src/v0.8/shared/interfaces/LinkTokenInterface.sol";
+import {VRFV2PlusClient} from "@chainlink/contracts/src/v0.8/vrf/dev/libraries/VRFV2PlusClient.sol";
+
+/**
+ * Request testnet LINK and ETH here: https://faucets.chain.link/
+ * Find information on LINK Token Contracts and get the latest ETH and LINK faucets here: https://docs.chain.link/docs/link-token-contracts/
+ */
+
+/**
+ * THIS IS AN EXAMPLE CONTRACT THAT USES HARDCODED VALUES FOR CLARITY.
+ * THIS IS AN EXAMPLE CONTRACT THAT USES UN-AUDITED CODE.
+ * DO NOT USE THIS CODE IN PRODUCTION.
+ */
+
+/**
+ * Import IVRFV2PlusWrapper which is not yet available in the chainlink/contracts package.
+ * https://github.com/smartcontractkit/chainlink/blob/develop/contracts/src/v0.8/vrf/dev/interfaces/IVRFV2PlusWrapper.sol
+ */
+
+interface IVRFV2PlusWrapper {
+    /**
+     * @return the request ID of the most recent VRF V2 request made by this wrapper. This should only
+     * be relied option within the same transaction that the request was made.
+     */
+    function lastRequestId() external view returns (uint256);
+
+    /**
+     * @notice Calculates the price of a VRF request with the given callbackGasLimit at the current
+     * @notice block.
+     *
+     * @dev This function relies on the transaction gas price which is not automatically set during
+     * @dev simulation. To estimate the price at a specific gas price, use the estimatePrice function.
+     *
+     * @param _callbackGasLimit is the gas limit used to estimate the price.
+     * @param _numWords is the number of words to request.
+     */
+    function calculateRequestPrice(
+        uint32 _callbackGasLimit,
+        uint32 _numWords
+    ) external view returns (uint256);
+
+    /**
+     * @notice Calculates the price of a VRF request in native with the given callbackGasLimit at the current
+     * @notice block.
+     *
+     * @dev This function relies on the transaction gas price which is not automatically set during
+     * @dev simulation. To estimate the price at a specific gas price, use the estimatePrice function.
+     *
+     * @param _callbackGasLimit is the gas limit used to estimate the price.
+     * @param _numWords is the number of words to request.
+     */
+    function calculateRequestPriceNative(
+        uint32 _callbackGasLimit,
+        uint32 _numWords
+    ) external view returns (uint256);
+
+    /**
+     * @notice Estimates the price of a VRF request with a specific gas limit and gas price.
+     *
+     * @dev This is a convenience function that can be called in simulation to better understand
+     * @dev pricing.
+     *
+     * @param _callbackGasLimit is the gas limit used to estimate the price.
+     * @param _numWords is the number of words to request.
+     * @param _requestGasPriceWei is the gas price in wei used for the estimation.
+     */
+    function estimateRequestPrice(
+        uint32 _callbackGasLimit,
+        uint32 _numWords,
+        uint256 _requestGasPriceWei
+    ) external view returns (uint256);
+
+    /**
+     * @notice Estimates the price of a VRF request in native with a specific gas limit and gas price.
+     *
+     * @dev This is a convenience function that can be called in simulation to better understand
+     * @dev pricing.
+     *
+     * @param _callbackGasLimit is the gas limit used to estimate the price.
+     * @param _numWords is the number of words to request.
+     * @param _requestGasPriceWei is the gas price in wei used for the estimation.
+     */
+    function estimateRequestPriceNative(
+        uint32 _callbackGasLimit,
+        uint32 _numWords,
+        uint256 _requestGasPriceWei
+    ) external view returns (uint256);
+
+    /**
+     * @notice Requests randomness from the VRF V2 wrapper, paying in native token.
+     *
+     * @param _callbackGasLimit is the gas limit for the request.
+     * @param _requestConfirmations number of request confirmations to wait before serving a request.
+     * @param _numWords is the number of words to request.
+     */
+    function requestRandomWordsInNative(
+        uint32 _callbackGasLimit,
+        uint16 _requestConfirmations,
+        uint32 _numWords,
+        bytes calldata extraArgs
+    ) external payable returns (uint256 requestId);
+
+    function link() external view returns (address);
+
+    function linkNativeFeed() external view returns (address);
+}
+
+/**
+ * Import VRFV2PlusWrapperConsumerBase which is not yet available in the chainlink/contracts package.
+ * https://github.com/smartcontractkit/chainlink/blob/develop/contracts/src/v0.8/vrf/dev/VRFV2PlusWrapperConsumerBase.sol
+ */
+
+abstract contract VRFV2PlusWrapperConsumerBase {
+    error OnlyVRFWrapperCanFulfill(address have, address want);
+
+    LinkTokenInterface internal immutable i_linkToken;
+    IVRFV2PlusWrapper public immutable i_vrfV2PlusWrapper;
+
+    /**
+     * @param _vrfV2PlusWrapper is the address of the VRFV2Wrapper contract
+     */
+    constructor(address _vrfV2PlusWrapper) {
+        IVRFV2PlusWrapper vrfV2PlusWrapper = IVRFV2PlusWrapper(
+            _vrfV2PlusWrapper
+        );
+
+        i_linkToken = LinkTokenInterface(vrfV2PlusWrapper.link());
+        i_vrfV2PlusWrapper = vrfV2PlusWrapper;
+    }
+
+    /**
+     * @dev Requests randomness from the VRF V2+ wrapper.
+     *
+     * @param _callbackGasLimit is the gas limit that should be used when calling the consumer's
+     *        fulfillRandomWords function.
+     * @param _requestConfirmations is the number of confirmations to wait before fulfilling the
+     *        request. A higher number of confirmations increases security by reducing the likelihood
+     *        that a chain re-org changes a published randomness outcome.
+     * @param _numWords is the number of random words to request.
+     *
+     * @return requestId is the VRF V2+ request ID of the newly created randomness request.
+     */
+    // solhint-disable-next-line chainlink-solidity/prefix-internal-functions-with-underscore
+    function requestRandomness(
+        uint32 _callbackGasLimit,
+        uint16 _requestConfirmations,
+        uint32 _numWords,
+        bytes memory extraArgs
+    ) internal returns (uint256 requestId, uint256 reqPrice) {
+        reqPrice = i_vrfV2PlusWrapper.calculateRequestPrice(
+            _callbackGasLimit,
+            _numWords
+        );
+        i_linkToken.transferAndCall(
+            address(i_vrfV2PlusWrapper),
+            reqPrice,
+            abi.encode(
+                _callbackGasLimit,
+                _requestConfirmations,
+                _numWords,
+                extraArgs
+            )
+        );
+        return (i_vrfV2PlusWrapper.lastRequestId(), reqPrice);
+    }
+
+    // solhint-disable-next-line chainlink-solidity/prefix-internal-functions-with-underscore
+    function requestRandomnessPayInNative(
+        uint32 _callbackGasLimit,
+        uint16 _requestConfirmations,
+        uint32 _numWords,
+        bytes memory extraArgs
+    ) internal returns (uint256 requestId, uint256 requestPrice) {
+        requestPrice = i_vrfV2PlusWrapper.calculateRequestPriceNative(
+            _callbackGasLimit,
+            _numWords
+        );
+        return (
+            i_vrfV2PlusWrapper.requestRandomWordsInNative{value: requestPrice}(
+                _callbackGasLimit,
+                _requestConfirmations,
+                _numWords,
+                extraArgs
+            ),
+            requestPrice
+        );
+    }
+
+    /**
+     * @notice fulfillRandomWords handles the VRF V2 wrapper response. The consuming contract must
+     * @notice implement it.
+     *
+     * @param _requestId is the VRF V2 request ID.
+     * @param _randomWords is the randomness result.
+     */
+    // solhint-disable-next-line chainlink-solidity/prefix-internal-functions-with-underscore
+    function fulfillRandomWords(
+        uint256 _requestId,
+        uint256[] memory _randomWords
+    ) internal virtual;
+
+    function rawFulfillRandomWords(
+        uint256 _requestId,
+        uint256[] memory _randomWords
+    ) external {
+        address vrfWrapperAddr = address(i_vrfV2PlusWrapper);
+        if (msg.sender != vrfWrapperAddr) {
+            revert OnlyVRFWrapperCanFulfill(msg.sender, vrfWrapperAddr);
+        }
+        fulfillRandomWords(_requestId, _randomWords);
+    }
+
+    /// @notice getBalance returns the native balance of the consumer contract
+    function getBalance() public view returns (uint256) {
+        return address(this).balance;
+    }
+
+    /// @notice getLinkToken returns the link token contract
+    function getLinkToken() public view returns (LinkTokenInterface) {
+        return i_linkToken;
+    }
+}
+
+contract DirectFundingConsumer is VRFV2PlusWrapperConsumerBase, ConfirmedOwner {
+    event RequestSent(uint256 requestId, uint32 numWords);
+    event RequestFulfilled(
+        uint256 requestId,
+        uint256[] randomWords,
+        uint256 payment
+    );
+
+    struct RequestStatus {
+        uint256 paid; // amount paid in link
+        bool fulfilled; // whether the request has been successfully fulfilled
+        uint256[] randomWords;
+    }
+    mapping(uint256 => RequestStatus)
+        public s_requests; /* requestId --> requestStatus */
+
+    // past requests Id.
+    uint256[] public requestIds;
+    uint256 public lastRequestId;
+
+    // Depends on the number of requested values that you want sent to the
+    // fulfillRandomWords() function. Test and adjust
+    // this limit based on the network that you select, the size of the request,
+    // and the processing of the callback request in the fulfillRandomWords()
+    // function.
+    uint32 callbackGasLimit = 100000;
+
+    // The default is 3, but you can set this higher.
+    uint16 requestConfirmations = 3;
+
+    // For this example, retrieve 2 random values in one request.
+    // Cannot exceed VRFV2Wrapper.getConfig().maxNumWords.
+    uint32 numWords = 2;
+
+    // Address LINK - hardcoded for Arbitrum Sepolia
+    address linkAddress = 0xb1D4538B4571d411F07960EF2838Ce337FE1E80E;
+
+    // address WRAPPER - hardcoded for Arbitrum Sepolia
+    address wrapperAddress = 0x29576aB8152A09b9DC634804e4aDE73dA1f3a3CC;
+
+    constructor()
+        ConfirmedOwner(msg.sender)
+        VRFV2PlusWrapperConsumerBase(wrapperAddress)
+    {}
+
+    function requestRandomWords() external onlyOwner returns (uint256) {
+        bytes memory extraArgs = VRFV2PlusClient._argsToBytes(
+            VRFV2PlusClient.ExtraArgsV1({nativePayment: false})
+        );
+        (uint256 requestId, uint256 reqPrice) = requestRandomness(
+            callbackGasLimit,
+            requestConfirmations,
+            numWords,
+            extraArgs
+        );
+        s_requests[requestId] = RequestStatus({
+            paid: reqPrice,
+            randomWords: new uint256[](0),
+            fulfilled: false
+        });
+        requestIds.push(requestId);
+        lastRequestId = requestId;
+        emit RequestSent(requestId, numWords);
+        return requestId;
+    }
+
+    function fulfillRandomWords(
+        uint256 _requestId,
+        uint256[] memory _randomWords
+    ) internal override {
+        require(s_requests[_requestId].paid > 0, "request not found");
+        s_requests[_requestId].fulfilled = true;
+        s_requests[_requestId].randomWords = _randomWords;
+        emit RequestFulfilled(
+            _requestId,
+            _randomWords,
+            s_requests[_requestId].paid
+        );
+    }
+
+    function getRequestStatus(
+        uint256 _requestId
+    )
+        external
+        view
+        returns (uint256 paid, bool fulfilled, uint256[] memory randomWords)
+    {
+        require(s_requests[_requestId].paid > 0, "request not found");
+        RequestStatus memory request = s_requests[_requestId];
+        return (request.paid, request.fulfilled, request.randomWords);
+    }
+
+    /**
+     * Allow withdraw of Link tokens from the contract
+     */
+    function withdrawLink() public onlyOwner {
+        LinkTokenInterface link = LinkTokenInterface(linkAddress);
+        require(
+            link.transfer(msg.sender, link.balanceOf(address(this))),
+            "Unable to transfer"
+        );
+    }
+}