fix: add generic factory interface

packages/contracts-bedrock/src/L2/IOptimismERC20Factory.sol

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/// @title IOptimismERC20Factory
+/// @notice Generic interface for IOptimismMintableERC20Factory and ISuperchainERC20Factory. Used to
+///         determine if a ERC20 contract is deployed by a factory.
+interface IOptimismERC20Factory {
+    /// @notice Checks if a ERC20 token is deployed by the factory.
+    /// @param _token The address of the ERC20 token to check the deployment.
+    /// @return _remoteToken The address of the remote token if it is deployed or `address(0)` if not.
+    function deployments(address _token) external view returns (address _remoteToken);
+}

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

@@ -5,6 +5,7 @@ import { Predeploys } from "src/libraries/Predeploys.sol";
 import { L2StandardBridge } from "src/L2/L2StandardBridge.sol";
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { IERC20Metadata } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
+import { IOptimismERC20Factory } from "src/L2/IOptimismERC20Factory.sol";
 
 /// @notice Thrown when the decimals of the tokens are not the same.
 error InvalidDecimals();
@@ -18,16 +19,6 @@ 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;
@@ -82,12 +73,12 @@ contract L2StandardBridgeInterop is L2StandardBridge {
     function _validateFactories(address _legacyAddr, address _superAddr) internal view {
         // 2. Valid legacy check
         address _legacyRemoteToken =
-            IOptimismMintableERC20Factory(Predeploys.OPTIMISM_MINTABLE_ERC20_FACTORY).deployments(_legacyAddr);
+            IOptimismERC20Factory(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);
+            IOptimismERC20Factory(Predeploys.OPTIMISM_SUPERCHAIN_ERC20_FACTORY).deployments(_superAddr);
         if (_superRemoteToken == address(0)) revert InvalidSuperchainAddress();
 
         // 4. Same remote address check

packages/contracts-bedrock/test/L2/L2StandardBridgeInterop.t.sol

@@ -12,7 +12,7 @@ import {
     InvalidLegacyAddress,
     InvalidSuperchainAddress,
     InvalidTokenPair,
-    IOptimismMintableERC20Factory,
+    IOptimismERC20Factory,
     MintableAndBurnable
 } from "src/L2/L2StandardBridgeInterop.sol";
 import { IERC20Metadata } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
@@ -47,9 +47,7 @@ contract L2StandardBridgeInterop_Test is Bridge_Initializer {
     /// @notice Mock factory deployment
     function _mockDeployments(address _factory, address _token, address _deployed) internal {
         _mockAndExpect(
-            _factory,
-            abi.encodeWithSelector(IOptimismMintableERC20Factory.deployments.selector, _token),
-            abi.encode(_deployed)
+            _factory, abi.encodeWithSelector(IOptimismERC20Factory.deployments.selector, _token), abi.encode(_deployed)
         );
     }
 }