SMR-1834-WETH-Bridging

.env.sample

@@ -10,4 +10,6 @@ ROOT_GAS_SERVICE_ADDRESS=
 CHILD_GAS_SERVICE_ADDRESS=
 ROOT_CHAIN_NAME=
 CHILD_CHAIN_NAME=
-ROOT_IMX_ADDRESS=
+ROOT_IMX_ADDRESS=
+ROOT_WETH_ADDRESS=
+ENVIRONMENT=

.gitignore

@@ -1,6 +1,7 @@
 # Compiler files
 cache/
 out/
+.idea/
 
 # Ignores development broadcast logs
 !/broadcast

README.md

@@ -138,10 +138,11 @@ ROOT_GATEWAY_ADDRESS="0x013459EC3E8Aeced878C5C4bFfe126A366cd19E9"
 CHILD_GATEWAY_ADDRESS="0xc7B788E88BAaB770A6d4936cdcCcd5250E1bbAd8"
 ROOT_GAS_SERVICE_ADDRESS="0x28f8B50E1Be6152da35e923602a2641491E71Ed8"
 CHILD_GAS_SERVICE_ADDRESS="0xC573c722e21eD7fadD38A8f189818433e01Ae466"
-
+ENVIRONMENT="local"
 ```
 (Note that `{ROOT,CHILD}_PRIVATE_KEY` can be any of the standard localhost private keys that get funded)
 (Note that `ROOT_IMX_ADDRESS` is not currently used in this local environment. Therefore, any non-zero address is fine.)
+(Note that `ENVIRONMENT` if the environment is not set to "local" then ROOT_WETH_ADDRESS will need to be manually set in the .env file since it is expected WETH to be already deployed on testnet or mainnet)
 
 3. In a separate terminal window, deploy the smart contracts
 ```shell

deploy.sh

@@ -13,6 +13,7 @@ function get_deployed_contract() {
 }
 
 function main() {
+
     forge script script/DeployRootContracts.s.sol:DeployRootContracts --broadcast
     forge script script/DeployChildContracts.s.sol:DeployChildContracts --broadcast
 
@@ -23,6 +24,11 @@ function main() {
     root_erc20_bridge=$( get_deployed_contract "$root_filename" "RootERC20Bridge" )
     root_bridge_adaptor=$( get_deployed_contract "$root_filename" "RootAxelarBridgeAdaptor" )
     root_chain_child_token_template=$( get_deployed_contract "$root_filename" "ChildERC20" )
+
+    if [ "$ENVIRONMENT" = "local" ]; then
+        root_weth_contract=$( get_deployed_contract "$root_filename" "WETH" )
+        export ROOT_WETH_ADDRESS=$root_weth_contract
+    fi
 
     child_erc20_bridge=$( get_deployed_contract "$child_filename" "ChildERC20Bridge" )
     child_bridge_adaptor=$( get_deployed_contract "$child_filename" "ChildAxelarBridgeAdaptor" )
@@ -31,6 +37,7 @@ function main() {
     export ROOT_ERC20_BRIDGE=$root_erc20_bridge
     export ROOT_BRIDGE_ADAPTOR=$root_bridge_adaptor
     export ROOTCHAIN_CHILD_TOKEN_TEMPLATE=$root_chain_child_token_template
+
     export CHILD_BRIDGE_ADAPTOR=$child_bridge_adaptor
     export CHILD_ERC20_BRIDGE=$child_erc20_bridge
     export CHILDCHAIN_CHILD_TOKEN_TEMPLATE=$child_chain_child_token_template

script/DeployRootContracts.s.sol

@@ -9,6 +9,7 @@ import {RootAxelarBridgeAdaptor} from "../src/root/RootAxelarBridgeAdaptor.sol";
 import {ChildERC20Bridge} from "../src/child/ChildERC20Bridge.sol";
 import {ChildAxelarBridgeAdaptor} from "../src/child/ChildAxelarBridgeAdaptor.sol";
 import {Strings} from "@openzeppelin/contracts/utils/Strings.sol";
+import {WETH} from "../src/test/root/WETH.sol";
 
 // TODO update private key usage to be more secure: https://book.getfoundry.sh/reference/forge/forge-script#wallet-options---raw
 
@@ -19,6 +20,7 @@ contract DeployRootContracts is Script {
         address rootGateway = vm.envAddress("ROOT_GATEWAY_ADDRESS");
         address rootGasService = vm.envAddress("ROOT_GAS_SERVICE_ADDRESS");
         string memory childChainName = vm.envString("CHILD_CHAIN_NAME");
+        string memory deployEnvironment = vm.envString("ENVIRONMENT");
 
         /**
          * DEPLOY ROOT CHAIN CONTRACTS
@@ -39,11 +41,15 @@ contract DeployRootContracts is Script {
             rootGasService // axelar gas service
         );
 
+        if (Strings.equal(deployEnvironment, "local")) {
+            new WETH();
+        }
+
+        vm.stopBroadcast();
+
         console2.log("====ROOT ADDRESSES====");
         console2.log("Root ERC20 Bridge: %s", address(rootERC20Bridge));
         console2.log("Root Axelar Bridge Adaptor: %s", address(rootBridgeAdaptor));
         console2.log("ROOT CHAIN childTokenTemplate: %s", address(rootChainChildTokenTemplate));
-
-        vm.stopBroadcast();
     }
 }

script/InitializeRootContracts.s.sol

@@ -15,14 +15,15 @@ import {Utils} from "./Utils.sol";
 
 contract InitializeRootContracts is Script {
     function run() public {
-        RootERC20Bridge rootERC20Bridge = RootERC20Bridge(vm.envAddress("ROOT_ERC20_BRIDGE"));
+        RootERC20Bridge rootERC20Bridge = RootERC20Bridge(payable(vm.envAddress("ROOT_ERC20_BRIDGE")));
         RootAxelarBridgeAdaptor rootBridgeAdaptor = RootAxelarBridgeAdaptor(vm.envAddress("ROOT_BRIDGE_ADAPTOR"));
         address rootChainChildTokenTemplate = vm.envAddress("ROOTCHAIN_CHILD_TOKEN_TEMPLATE");
         address childBridgeAdaptor = vm.envAddress("CHILD_BRIDGE_ADAPTOR");
         address childERC20Bridge = vm.envAddress("CHILD_ERC20_BRIDGE");
         string memory rootRpcUrl = vm.envString("ROOT_RPC_URL");
         uint256 rootPrivateKey = vm.envUint("ROOT_PRIVATE_KEY");
         address rootIMXToken = vm.envAddress("ROOT_IMX_ADDRESS");
+        address rootWETHToken = vm.envAddress("ROOT_WETH_ADDRESS");
 
         string[] memory checksumInputs = Utils.getChecksumInputs(childBridgeAdaptor);
         bytes memory checksumOutput = vm.ffi(checksumInputs);
@@ -38,7 +39,8 @@ contract InitializeRootContracts is Script {
             childERC20Bridge,
             childBridgeAdaptorChecksum,
             rootChainChildTokenTemplate,
-            rootIMXToken
+            rootIMXToken,
+            rootWETHToken
         );
 
         rootBridgeAdaptor.setChildBridgeAdaptor();

src/interfaces/root/IRootERC20Bridge.sol

@@ -46,6 +46,13 @@ interface IRootERC20BridgeEvents {
         uint256 amount
     );
     event IMXDeposit(address indexed rootToken, address depositor, address indexed receiver, uint256 amount);
+    event WETHDeposit(
+        address indexed rootToken,
+        address indexed childToken,
+        address depositor,
+        address indexed receiver,
+        uint256 amount
+    );
     event NativeEthDeposit(
         address indexed rootToken,
         address indexed childToken,
@@ -70,6 +77,8 @@ interface IRootERC20BridgeErrors {
     error CantMapIMX();
     /// @notice Error when attempting to map ETH.
     error CantMapETH();
+    /// @notice Error when attempting to map wETH.
+    error CantMapWETH();
     /// @notice Error when token balance invariant check fails.
     error BalanceInvariantCheckFailed(uint256 actualBalance, uint256 expectedBalance);
     /// @notice Error when the given child chain bridge adaptor is invalid.

src/interfaces/root/IWETH.sol

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: Apache 2.0
+pragma solidity ^0.8.21;
+
+import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+/**
+ * @dev Interface of Wrapped ETH.
+ */
+interface IWETH is IERC20 {
+    /**
+     * @dev Emitted when `value` native ETH are deposited from `account`.
+     */
+    event Deposit(address indexed account, uint256 value);
+
+    /**
+     * @dev Emitted when `value` wETH tokens are withdrawn to `account`.
+     */
+    event Withdrawal(address indexed account, uint256 value);
+
+    /**
+     * @notice Deposit native ETH in the function call and mint the equal amount of wrapped ETH to msg.sender.
+     */
+    function deposit() external payable;
+
+    /**
+     * @notice Withdraw given amount of native ETH to msg.sender and burn the equal amount of wrapped ETH.
+     * @param value The amount to withdraw.
+     */
+    function withdraw(uint256 value) external;
+}

src/root/RootERC20Bridge.sol

@@ -12,6 +12,7 @@ import {IRootERC20Bridge, IERC20Metadata} from "../interfaces/root/IRootERC20Bri
 import {IRootERC20BridgeEvents, IRootERC20BridgeErrors} from "../interfaces/root/IRootERC20Bridge.sol";
 import {IRootERC20BridgeAdaptor} from "../interfaces/root/IRootERC20BridgeAdaptor.sol";
 import {IChildERC20} from "../interfaces/child/IChildERC20.sol";
+import {IWETH} from "../interfaces/root/IWETH.sol";
 
 /**
  * @notice RootERC20Bridge is a bridge that allows ERC20 tokens to be transferred from the root chain to the child chain.
@@ -21,6 +22,7 @@ import {IChildERC20} from "../interfaces/child/IChildERC20.sol";
  * @dev Because of this pattern, any checks or logic that is agnostic to the messaging protocol should be done in RootERC20Bridge.
  * @dev Any checks or logic that is specific to the underlying messaging protocol should be done in the bridge adaptor.
  */
+
 contract RootERC20Bridge is
     Ownable2Step,
     Initializable,
@@ -48,6 +50,8 @@ contract RootERC20Bridge is
     address public rootIMXToken;
     /// @dev The address of the ETH ERC20 token on L2.
     address public childETHToken;
+    /// @dev The address of the wETH ERC20 token on L1.
+    address public rootWETHToken;
 
     /**
      * @notice Initilization function for RootERC20Bridge.
@@ -56,18 +60,20 @@ contract RootERC20Bridge is
      * @param newChildBridgeAdaptor Address of child bridge adaptor to communicate with (As a checksummed string).
      * @param newChildTokenTemplate Address of child token template to clone.
      * @param newRootIMXToken Address of ERC20 IMX on the root chain.
+     * @param newRootWETHToken Address of ERC20 WETH on the root chain.
      * @dev Can only be called once.
      */
     function initialize(
         address newRootBridgeAdaptor,
         address newChildERC20Bridge,
         string memory newChildBridgeAdaptor,
         address newChildTokenTemplate,
-        address newRootIMXToken
+        address newRootIMXToken,
+        address newRootWETHToken
     ) public initializer {
         if (
             newRootBridgeAdaptor == address(0) || newChildERC20Bridge == address(0)
-                || newChildTokenTemplate == address(0) || newRootIMXToken == address(0)
+                || newChildTokenTemplate == address(0) || newRootIMXToken == address(0) || newRootWETHToken == address(0)
         ) {
             revert ZeroAddress();
         }
@@ -77,14 +83,26 @@ contract RootERC20Bridge is
         childERC20Bridge = newChildERC20Bridge;
         childTokenTemplate = newChildTokenTemplate;
         rootIMXToken = newRootIMXToken;
-
+        rootWETHToken = newRootWETHToken;
         childETHToken = Clones.predictDeterministicAddress(
             childTokenTemplate, keccak256(abi.encodePacked(NATIVE_ETH)), childERC20Bridge
         );
         rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
         childBridgeAdaptor = newChildBridgeAdaptor;
     }
 
+    function updateRootBridgeAdaptor(address newRootBridgeAdaptor) external onlyOwner {
+        if (newRootBridgeAdaptor == address(0)) {
+            revert ZeroAddress();
+        }
+        rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
+    }
+
+    /**
+     * @dev method to receive the ETH back from the WETH contract when it is unwrapped
+     */
+    receive() external payable {}
+
     /**
      * @inheritdoc IRootERC20Bridge
      * @dev TODO when this becomes part of the deposit flow on a token's first bridge, this logic will need to be mostly moved into an internal function.
@@ -97,15 +115,27 @@ contract RootERC20Bridge is
     }
 
     function depositETH(uint256 amount) external payable {
-        //override removed?
         _depositETH(msg.sender, amount);
     }
 
     function depositToETH(address receiver, uint256 amount) external payable {
-        //override removed?
         _depositETH(receiver, amount);
     }
 
+    /**
+     * @inheritdoc IRootERC20Bridge
+     */
+    function deposit(IERC20Metadata rootToken, uint256 amount) external payable override {
+        _depositToken(rootToken, msg.sender, amount);
+    }
+
+    /**
+     * @inheritdoc IRootERC20Bridge
+     */
+    function depositTo(IERC20Metadata rootToken, address receiver, uint256 amount) external payable override {
+        _depositToken(rootToken, receiver, amount);
+    }
+
     function _depositETH(address receiver, uint256 amount) private {
         if (msg.value < amount) {
             revert InsufficientValue();
@@ -121,18 +151,27 @@ contract RootERC20Bridge is
         }
     }
 
-    /**
-     * @inheritdoc IRootERC20Bridge
-     */
-    function deposit(IERC20Metadata rootToken, uint256 amount) external payable override {
-        _depositERC20(rootToken, msg.sender, amount);
+    function _depositToken(IERC20Metadata rootToken, address receiver, uint256 amount) private {
+        if (address(rootToken) == rootWETHToken) {
+            _depositWrappedETH(receiver, amount);
+        } else {
+            _depositERC20(rootToken, receiver, amount);
+        }
     }
 
-    /**
-     * @inheritdoc IRootERC20Bridge
-     */
-    function depositTo(IERC20Metadata rootToken, address receiver, uint256 amount) external payable override {
-        _depositERC20(rootToken, receiver, amount);
+    function _depositWrappedETH(address receiver, uint256 amount) private {
+        uint256 expectedBalance = address(this).balance + amount;
+
+        IERC20Metadata erc20WETH = IERC20Metadata(rootWETHToken);
+
+        erc20WETH.safeTransferFrom(msg.sender, address(this), amount);
+        IWETH(rootWETHToken).withdraw(amount);
+
+        // invariant check to ensure that the root native balance has increased by the amount deposited
+        if (address(this).balance != expectedBalance) {
+            revert BalanceInvariantCheckFailed(address(this).balance, expectedBalance);
+        }
+        _deposit(IERC20Metadata(rootWETHToken), receiver, amount);
     }
 
     function _depositERC20(IERC20Metadata rootToken, address receiver, uint256 amount) private {
@@ -157,6 +196,10 @@ contract RootERC20Bridge is
             revert CantMapETH();
         }
 
+        if (address(rootToken) == rootWETHToken) {
+            revert CantMapWETH();
+        }
+
         if (rootTokenToChildToken[address(rootToken)] != address(0)) {
             revert AlreadyMapped();
         }
@@ -181,52 +224,50 @@ contract RootERC20Bridge is
         if (receiver == address(0) || address(rootToken) == address(0)) {
             revert ZeroAddress();
         }
-
         if (amount == 0) {
             revert ZeroAmount();
         }
 
-        address childToken;
-        uint256 feeAmount;
+        // ETH, WETH and IMX do not need to be mapped since it should have been mapped on initialization
+        // ETH also cannot be transferred since it was received in the payable function call
+        // WETH is also not transferred here since it was earlier unwrapped to ETH
 
-        // The native token does not need to be mapped since it should have been mapped on initialization
-        // The native token also cannot be transferred since it was received in the payable function call
         // TODO We can call _mapToken here, but ordering in the GMP is not guaranteed.
-        //      Therefore, we need to decide how to handle this and it may be a UI decision to wait until map token message is executed on child chain.
-        //      Discuss this, and add this decision to the design doc.
-        if (address(rootToken) != NATIVE_ETH) {
+        // Therefore, we need to decide how to handle this and it may be a UI decision to wait until map token message is executed on child chain.
+        // Discuss this, and add this decision to the design doc.
+
+        address childToken;
+        uint256 feeAmount = msg.value;
+        address payloadToken = address(rootToken);
+
+        if (address(rootToken) == NATIVE_ETH) {
+            feeAmount = msg.value - amount;
+        } else if (address(rootToken) == rootWETHToken) {
+            payloadToken = NATIVE_ETH;
+        } else {
             if (address(rootToken) != rootIMXToken) {
                 childToken = rootTokenToChildToken[address(rootToken)];
                 if (childToken == address(0)) {
                     revert NotMapped();
                 }
             }
-            // ERC20 must be transferred explicitly
             rootToken.safeTransferFrom(msg.sender, address(this), amount);
-            feeAmount = msg.value;
-        } else {
-            feeAmount = msg.value - amount;
         }
 
         // Deposit sig, root token address, depositor, receiver, amount
-        bytes memory payload = abi.encode(DEPOSIT_SIG, rootToken, msg.sender, receiver, amount);
-        // TODO investigate using delegatecall to keep the axelar message sender as the bridge contract, since adaptor can change.
+        bytes memory payload = abi.encode(DEPOSIT_SIG, payloadToken, msg.sender, receiver, amount);
 
+        // TODO investigate using delegatecall to keep the axelar message sender as the bridge contract, since adaptor can change.
         rootBridgeAdaptor.sendMessage{value: feeAmount}(payload, msg.sender);
 
         if (address(rootToken) == NATIVE_ETH) {
             emit NativeEthDeposit(address(rootToken), childETHToken, msg.sender, receiver, amount);
+        } else if (address(rootToken) == rootWETHToken) {
+            emit WETHDeposit(address(rootToken), childETHToken, msg.sender, receiver, amount);
         } else if (address(rootToken) == rootIMXToken) {
             emit IMXDeposit(address(rootToken), msg.sender, receiver, amount);
         } else {
             emit ERC20Deposit(address(rootToken), childToken, msg.sender, receiver, amount);
         }
     }
-
-    function updateRootBridgeAdaptor(address newRootBridgeAdaptor) external onlyOwner {
-        if (newRootBridgeAdaptor == address(0)) {
-            revert ZeroAddress();
-        }
-        rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
-    }
 }