Yield-earning Warp Routes with ERC4626

solidity/contracts/hooks/libs/AbstractMessageIdAuthHook.sol

@@ -78,6 +78,10 @@ abstract contract AbstractMessageIdAuthHook is
             message.destination() == destinationDomain,
             "AbstractMessageIdAuthHook: invalid destination domain"
         );
+        require(
+            metadata.msgValue(0) < 2 ** 255,
+            "AbstractMessageIdAuthHook: msgValue must be less than 2 ** 255"
+        );
         bytes memory payload = abi.encodeCall(
             AbstractMessageIdAuthorizedIsm.verifyMessageId,
             id

solidity/contracts/test/ERC20Test.sol

@@ -19,4 +19,12 @@ contract ERC20Test is ERC20 {
     function decimals() public view override returns (uint8) {
         return _decimals;
     }
+
+    function mint(uint256 amount) public {
+        _mint(msg.sender, amount);
+    }
+
+    function mintTo(address account, uint256 amount) public {
+        _mint(account, amount);
+    }
 }

solidity/contracts/test/ERC4626/ERC4626Test.sol

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity >=0.8.0;
+import "@openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol";
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import "@openzeppelin/contracts/interfaces/IERC20.sol";
+
+contract ERC4626Test is ERC4626 {
+    constructor(
+        address _asset,
+        string memory _name,
+        string memory _symbol
+    ) ERC4626(IERC20(_asset)) ERC20(_name, _symbol) {}
+}

solidity/contracts/token/HypERC20Collateral.sol

@@ -37,7 +37,7 @@ contract HypERC20Collateral is TokenRouter {
      */
     function _transferFromSender(
         uint256 _amount
-    ) internal override returns (bytes memory) {
+    ) internal virtual override returns (bytes memory) {
         wrappedToken.safeTransferFrom(msg.sender, address(this), _amount);
         return bytes(""); // no metadata
     }

solidity/contracts/token/HypERC20CollateralVaultDeposit.sol

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity >=0.8.0;
+import "@openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol";
+import {HypERC20Collateral} from "./HypERC20Collateral.sol";
+
+/**
+ * @title Hyperlane ERC20 Token Collateral with deposits collateral to a vault
+ * @author ltyu
+ */
+contract HypERC20CollateralVaultDeposit is HypERC20Collateral {
+    // Address of the ERC4626 compatible vault
+    ERC4626 public immutable vault;
+
+    // Internal balance of total asset deposited
+    uint256 public assetDeposited;
+
+    event ExcessSharesSwept(uint256 amount, uint256 assetsRedeemed);
+
+    constructor(
+        ERC4626 _vault,
+        address _mailbox
+    ) HypERC20Collateral(_vault.asset(), _mailbox) {
+        vault = _vault;
+        wrappedToken.approve(address(vault), type(uint256).max);
+    }
+
+    /**
+     * @dev Transfers `_amount` of `wrappedToken` from `msg.sender` to this contract, and deposit into vault
+     * @inheritdoc HypERC20Collateral
+     */
+    function _transferFromSender(
+        uint256 _amount
+    ) internal override returns (bytes memory metadata) {
+        metadata = super._transferFromSender(_amount);
+        _depositIntoVault(_amount);
+    }
+
+    /**
+     * @dev Deposits into the vault and increment assetDeposited
+     * @param _amount amount to deposit into vault
+     */
+    function _depositIntoVault(uint256 _amount) internal {
+        assetDeposited += _amount;
+        vault.deposit(_amount, address(this));
+    }
+
+    /**
+     * @dev Transfers `_amount` of `wrappedToken` from this contract to `_recipient`, and withdraws from vault
+     * @inheritdoc HypERC20Collateral
+     */
+    function _transferTo(
+        address _recipient,
+        uint256 _amount,
+        bytes calldata
+    ) internal virtual override {
+        _withdrawFromVault(_amount, _recipient);
+    }
+
+    /**
+     * @dev Withdraws from the vault and decrement assetDeposited
+     * @param _amount amount to withdraw from vault
+     * @param _recipient address to deposit withdrawn underlying to
+     */
+    function _withdrawFromVault(uint256 _amount, address _recipient) internal {
+        assetDeposited -= _amount;
+        vault.withdraw(_amount, _recipient, address(this));
+    }
+
+    /**
+     * @notice Allows the owner to redeem excess shares
+     */
+    function sweep() external onlyOwner {
+        uint256 excessShares = vault.maxRedeem(address(this)) -
+            vault.convertToShares(assetDeposited);
+        uint256 assetsRedeemed = vault.redeem(
+            excessShares,
+            owner(),
+            address(this)
+        );
+        emit ExcessSharesSwept(excessShares, assetsRedeemed);
+    }
+}

solidity/test/isms/OPStackIsm.t.sol

@@ -199,7 +199,9 @@ contract OPStackIsmTest is Test {
             .overrideMsgValue(uint256(2 ** 255 + 1));
 
         l1Mailbox.updateLatestDispatchedId(messageId);
-        vm.expectRevert("OPStackHook: msgValue must be less than 2 ** 255");
+        vm.expectRevert(
+            "AbstractMessageIdAuthHook: msgValue must be less than 2 ** 255"
+        );
         opHook.postDispatch(excessValueMetadata, encodedMessage);
     }
 

solidity/test/token/HypERC20.t.sol

@@ -103,6 +103,20 @@ abstract contract HypTokenTest is Test {
         );
     }
 
+    function _handleLocalTransfer(uint256 _transferAmount) internal {
+        vm.prank(address(localMailbox));
+        localToken.handle(
+            DESTINATION,
+            address(remoteToken).addressToBytes32(),
+            abi.encodePacked(ALICE.addressToBytes32(), _transferAmount)
+        );
+    }
+
+    function _mintAndApprove(uint256 _amount, address _account) internal {
+        primaryToken.mint(_amount);
+        primaryToken.approve(_account, _amount);
+    }
+
     function _setCustomGasConfig() internal {
         localToken.setHook(address(igp));
 
@@ -153,7 +167,7 @@ abstract contract HypTokenTest is Test {
         _performRemoteTransferAndGas(_msgValue, _amount, _gasOverhead);
     }
 
-    function testBenchmark_overheadGasUsage() public {
+    function testBenchmark_overheadGasUsage() public virtual {
         vm.prank(address(localMailbox));
 
         uint256 gasBefore = gasleft();