fix(contracts): OZ-L1-L07 Lack of Logs on Sensitive Actions

contracts/src/libraries/FeeVault.sol

@@ -28,17 +28,43 @@ pragma solidity ^0.8.0;
 import {IL2ScrollMessenger} from "../L2/IL2ScrollMessenger.sol";
 import {OwnableBase} from "./common/OwnableBase.sol";
 
+// solhint-disable no-empty-blocks
+// solhint-disable reason-string
+
 /// @title FeeVault
 /// @notice The FeeVault contract contains the basic logic for the various different vault contracts
 ///         used to hold fee revenue generated by the L2 system.
 abstract contract FeeVault is OwnableBase {
+    /**********
+     * Events *
+     **********/
+
     /// @notice Emits each time that a withdrawal occurs.
     ///
     /// @param value Amount that was withdrawn (in wei).
     /// @param to    Address that the funds were sent to.
     /// @param from  Address that triggered the withdrawal.
     event Withdrawal(uint256 value, address to, address from);
 
+    /// @notice Emits each time the owner updates the address of `messenger`.
+    /// @param oldMessenger The address of old messenger.
+    /// @param newMessenger The address of new messenger.
+    event UpdateMessenger(address indexed oldMessenger, address indexed newMessenger);
+
+    /// @notice Emits each time the owner updates the address of `recipient`.
+    /// @param oldRecipient The address of old recipient.
+    /// @param newRecipient The address of new recipient.
+    event UpdateRecipient(address indexed oldRecipient, address indexed newRecipient);
+
+    /// @notice Emits each time the owner updates the value of `minWithdrawAmount`.
+    /// @param oldMinWithdrawAmount The value of old `minWithdrawAmount`.
+    /// @param newMinWithdrawAmount The value of new `minWithdrawAmount`.
+    event UpdateMinWithdrawAmount(uint256 oldMinWithdrawAmount, uint256 newMinWithdrawAmount);
+
+    /*************
+     * Variables *
+     *************/
+
     /// @notice Minimum balance before a withdrawal can be triggered.
     uint256 public minWithdrawAmount;
 
@@ -51,6 +77,10 @@ abstract contract FeeVault is OwnableBase {
     /// @notice Total amount of wei processed by the contract.
     uint256 public totalProcessed;
 
+    /***************
+     * Constructor *
+     ***************/
+
     /// @param _owner               The owner of the contract.
     /// @param _recipient           Wallet that will receive the fees on L1.
     /// @param _minWithdrawalAmount Minimum balance before a withdrawal can be triggered.
@@ -65,6 +95,10 @@ abstract contract FeeVault is OwnableBase {
         recipient = _recipient;
     }
 
+    /*****************************
+     * Public Mutating Functions *
+     *****************************/
+
     /// @notice Allow the contract to receive ETH.
     receive() external payable {}
 
@@ -92,21 +126,34 @@ abstract contract FeeVault is OwnableBase {
         );
     }
 
+    /************************
+     * Restricted Functions *
+     ************************/
+
     /// @notice Update the address of messenger.
-    /// @param _messenger The address of messenger to update.
-    function updateMessenger(address _messenger) external onlyOwner {
-        messenger = _messenger;
+    /// @param _newMessenger The address of messenger to update.
+    function updateMessenger(address _newMessenger) external onlyOwner {
+        address _oldMessenger = messenger;
+        messenger = _newMessenger;
+
+        emit UpdateMessenger(_oldMessenger, _newMessenger);
     }
 
     /// @notice Update the address of recipient.
-    /// @param _recipient The address of recipient to update.
-    function updateRecipient(address _recipient) external onlyOwner {
-        recipient = _recipient;
+    /// @param _newRecipient The address of recipient to update.
+    function updateRecipient(address _newRecipient) external onlyOwner {
+        address _oldRecipient = recipient;
+        recipient = _newRecipient;
+
+        emit UpdateRecipient(_oldRecipient, _newRecipient);
     }
 
     /// @notice Update the minimum withdraw amount.
-    /// @param _minWithdrawAmount The minimum withdraw amount to update.
-    function updateMinWithdrawAmount(uint256 _minWithdrawAmount) external onlyOwner {
-        minWithdrawAmount = _minWithdrawAmount;
+    /// @param _newMinWithdrawAmount The minimum withdraw amount to update.
+    function updateMinWithdrawAmount(uint256 _newMinWithdrawAmount) external onlyOwner {
+        uint256 _oldMinWithdrawAmount = minWithdrawAmount;
+        minWithdrawAmount = _newMinWithdrawAmount;
+
+        emit UpdateMinWithdrawAmount(_oldMinWithdrawAmount, _newMinWithdrawAmount);
     }
 }

contracts/src/libraries/token/IScrollStandardERC20Factory.sol

@@ -3,6 +3,9 @@
 pragma solidity ^0.8.0;
 
 interface IScrollStandardERC20Factory {
+    /// @notice Emitted when a l2 token is deployed.
+    /// @param _l1Token The address of the l1 token.
+    /// @param _l2Token The address of the l2 token.
     event DeployToken(address indexed _l1Token, address indexed _l2Token);
 
     /// @notice Compute the corresponding l2 token address given l1 token address.

contracts/src/libraries/token/ScrollStandardERC20Factory.sol

@@ -35,7 +35,11 @@ contract ScrollStandardERC20Factory is Ownable, IScrollStandardERC20Factory {
     function deployL2Token(address _gateway, address _l1Token) external onlyOwner returns (address) {
         bytes32 _salt = _getSalt(_gateway, _l1Token);
 
-        return Clones.cloneDeterministic(implementation, _salt);
+        address _l2Token = Clones.cloneDeterministic(implementation, _salt);
+
+        emit DeployToken(_l1Token, _l2Token);
+
+        return _l2Token;
     }
 
     function _getSalt(address _gateway, address _l1Token) internal pure returns (bytes32) {