feat: add L2 standrad bridge interop contract

packages/contracts-bedrock/src/L2/L2StandardBridgeInterop.sol

@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.15;
+
+import { Predeploys } from "src/libraries/Predeploys.sol";
+import { L2StandardBridge } from "./L2StandardBridge.sol";
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import { IERC20Metadata } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
+
+/// @notice Thrown when the decimals of the tokens are not the same.
+error InvalidDecimals();
+
+/// @notice Thrown when the legacy address is not found in the OptimismMintableERC20Factory.
+error InvalidLegacyAddress();
+
+/// @notice Thrown when the SuperchainERC20 address is not found in the SuperchainERC20Factory.
+error InvalidSuperchainAddress();
+
+/// @notice Thrown when the remote addresses of the tokens are not the same.
+error InvalidTokenPair();
+
+// TODO: Use OptimismMintableERC20Factory contract instead of interface
+interface IOptimismMintableERC20Factory {
+    function deployments(address) external view returns (address);
+}
+
+// TODO: Move to a separate file
+interface ISuperchainERC20Factory {
+    function deployments(address) external view returns (address);
+}
+
+// TODO: Use an existing interface with `mint` and `burn`?
+interface MintableAndBurnable is IERC20 {
+    function mint(address, uint256) external;
+    function burn(address, uint256) external;
+}
+
+/// @custom:proxied
+/// @custom:predeploy 0x4200000000000000000000000000000000000010
+/// @title L2StandardBridgeInterop
+/// @notice The L2StandardBridgeInterop is an extension of the L2StandardBridge that allows for
+///         the conversion of tokens between legacy tokens (OptimismMintableERC20 or StandardL2ERC20)
+///         and SuperchainERC20 tokens.
+contract L2StandardBridgeInterop is L2StandardBridge {
+    /// @notice Emitted when a conversion is made.
+    /// @param from The token being converted from.
+    /// @param to The token being converted to.
+    /// @param caller The caller of the conversion.
+    /// @param amount The amount of tokens being converted.
+    event Converted(address indexed from, address indexed to, address indexed caller, uint256 amount);
+
+    /// @notice Converts `amount` of `from` token to `to` token.
+    /// @param _from The token being converted from.
+    /// @param _to The token being converted to.
+    /// @param _amount The amount of tokens being converted.
+    function convert(address _from, address _to, uint256 _amount) external {
+        _validatePair(_from, _to);
+
+        MintableAndBurnable(_from).burn(msg.sender, _amount);
+        MintableAndBurnable(_to).mint(msg.sender, _amount);
+
+        emit Converted(_from, _to, msg.sender, _amount);
+    }
+
+    /// @notice Validates the pair of tokens.
+    /// @param _from The token being converted from.
+    /// @param _to The token being converted to.
+    function _validatePair(address _from, address _to) internal view {
+        // 1. Decimals check
+        if (IERC20Metadata(_from).decimals() != IERC20Metadata(_to).decimals()) revert InvalidDecimals();
+
+        // Order tokens for factory validation
+        if (_isOptimismMintableERC20(_from)) {
+            _validateFactories(_from, _to);
+        } else {
+            _validateFactories(_to, _from);
+        }
+    }
+
+    /// @notice Validates that the tokens are deployed by the correct factory.
+    /// @param _legacyAddr The legacy token address (OptimismMintableERC20 or StandardL2ERC20).
+    /// @param _superAddr The SuperchainERC20 address.
+    function _validateFactories(address _legacyAddr, address _superAddr) internal view {
+        // 2. Valid legacy check
+        address _legacyRemoteToken =
+            IOptimismMintableERC20Factory(Predeploys.OPTIMISM_MINTABLE_ERC20_FACTORY).deployments(_legacyAddr);
+        if (_legacyRemoteToken == address(0)) revert InvalidLegacyAddress();
+
+        // 3. Valid SuperchainERC20 check
+        address _superRemoteToken =
+            ISuperchainERC20Factory(Predeploys.OPTIMISM_SUPERCHAIN_ERC20_FACTORY).deployments(_superAddr);
+        if (_superRemoteToken == address(0)) revert InvalidSuperchainAddress();
+
+        // 4. Same remote address check
+        if (_legacyRemoteToken != _superRemoteToken) revert InvalidTokenPair();
+    }
+}

packages/contracts-bedrock/src/libraries/Predeploys.sol

@@ -95,6 +95,9 @@ library Predeploys {
     /// @notice Address of the ETHLiquidity predeploy.
     address internal constant ETH_LIQUIDITY = 0x4200000000000000000000000000000000000025;
 
+    /// @notice Address of the OptimismSuperchainERC20Factory predeploy.
+    address internal constant OPTIMISM_SUPERCHAIN_ERC20_FACTORY = 0x4200000000000000000000000000000000000026;
+
     /// @notice Returns the name of the predeploy at the given address.
     function getName(address _addr) internal pure returns (string memory out_) {
         require(isPredeployNamespace(_addr), "Predeploys: address must be a predeploy");
@@ -123,6 +126,7 @@ library Predeploys {
         if (_addr == L2_TO_L2_CROSS_DOMAIN_MESSENGER) return "L2ToL2CrossDomainMessenger";
         if (_addr == SUPERCHAIN_WETH) return "SuperchainWETH";
         if (_addr == ETH_LIQUIDITY) return "ETHLiquidity";
+        if (_addr == OPTIMISM_SUPERCHAIN_ERC20_FACTORY) return "OptimismSuperchainERC20Factory";
         revert("Predeploys: unnamed predeploy");
     }
 
@@ -140,7 +144,8 @@ library Predeploys {
             || _addr == OPTIMISM_MINTABLE_ERC721_FACTORY || _addr == PROXY_ADMIN || _addr == BASE_FEE_VAULT
             || _addr == L1_FEE_VAULT || _addr == SCHEMA_REGISTRY || _addr == EAS || _addr == GOVERNANCE_TOKEN
             || (_useInterop && _addr == CROSS_L2_INBOX) || (_useInterop && _addr == L2_TO_L2_CROSS_DOMAIN_MESSENGER)
-            || (_useInterop && _addr == SUPERCHAIN_WETH) || (_useInterop && _addr == ETH_LIQUIDITY);
+            || (_useInterop && _addr == SUPERCHAIN_WETH) || (_useInterop && _addr == ETH_LIQUIDITY)
+            || (_useInterop && _addr == OPTIMISM_SUPERCHAIN_ERC20_FACTORY);
     }
 
     function isPredeployNamespace(address _addr) internal pure returns (bool) {