refactor(ctb): Remove the veto function.

This simplifies the interface, and the resulting handleCall
function is also cleaner, as it treats the dispatching primarily
based on the caller.

packages/contracts-bedrock/src/L1/DelayedVetoable.sol

@@ -49,8 +49,8 @@ contract DelayedVetoable is Semver {
     ///         eth_call to interact with this proxy without needing to use low-level storage
     ///         inspection. We assume that nobody is able to trigger calls from address(0) during
     ///         normal EVM execution.
-    modifier handleCallIfNotVetoer() {
-        if (msg.sender == _vetoer || msg.sender == address(0)) {
+    modifier readOrHandle() {
+        if (msg.sender == address(0)) {
             _;
         } else {
             // This WILL halt the call frame on completion.
@@ -73,25 +73,25 @@ contract DelayedVetoable is Semver {
 
     /// @notice Gets the initiator
     /// @return Initiator address.
-    function initiator() external handleCallIfNotVetoer returns (address) {
+    function initiator() external readOrHandle returns (address) {
         return _initiator;
     }
 
     //// @notice Queries the vetoer address.
     /// @return Vetoer address.
-    function vetoer() external handleCallIfNotVetoer returns (address) {
+    function vetoer() external readOrHandle returns (address) {
         return _vetoer;
     }
 
     //// @notice Queries the target address.
     /// @return Target address.
-    function target() external handleCallIfNotVetoer returns (address) {
+    function target() external readOrHandle returns (address) {
         return _target;
     }
 
     /// @notice Gets the delay
     /// @return Delay address.
-    function delay() external handleCallIfNotVetoer returns (uint256) {
+    function delay() external readOrHandle returns (uint256) {
         return _delay;
     }
 
@@ -110,32 +110,37 @@ contract DelayedVetoable is Semver {
         _handleCall();
     }
 
-    /// @notice Vetoes a call. This method can only be called by the vetoer. If called by another
-    ///         address, execution will be redirected to _handleCall()
-    function veto(bytes memory data) external handleCallIfNotVetoer {
-        bytes32 callHash = keccak256(data);
-
-        delete _queuedAt[callHash];
-        emit Vetoed(callHash, data);
-    }
-
     /// @notice Receives all calls other than those made by the vetoer.
     ///         This enables transparent initiation and forwarding of calls to the target and avoids
     ///         the need for additional layers of abi encoding.
     function _handleCall() internal {
         bytes32 callHash = keccak256(msg.data);
+
+        // Case 1: The initiator is calling the contract to initiate a call.
+        if (msg.sender == _initiator && _queuedAt[callHash] == 0) {
+            _queuedAt[callHash] = block.timestamp;
+            emit Initiated(callHash, msg.data);
+            return;
+        }
+
+        // Case 2: The vetoer is calling the contract to veto a call.
+        if (msg.sender == _vetoer && _queuedAt[callHash] != 0 && block.timestamp <= _queuedAt[callHash] + _delay) {
+            delete _queuedAt[callHash];
+            emit Vetoed(callHash, msg.data);
+            return;
+        }
+
+        // Case 3: The call is from an unpermissioned actor. We'll forward the call if the delay has
+        // passed.
         if (_queuedAt[callHash] == 0) {
-            if (msg.sender != _initiator) {
+            // The call has not been initiated, so we'll treat this is an unauthorized initiation attempt.
             revert Unauthorized(_initiator, msg.sender);
         }
-            _queuedAt[callHash] = block.timestamp;
-            emit Initiated(callHash, msg.data);
-        } else if (_queuedAt[callHash] + _delay < block.timestamp) {
+
+        if (_queuedAt[callHash] + _delay < block.timestamp) {
             // Not enough time has passed, so we'll revert.
             revert ForwardingEarly();
-        } else {
-            // The ability to finalize the call after sufficient time has passed does not require
-            // authorization.
+        }
 
         // Delete the call to prevent replays
         delete _queuedAt[callHash];
@@ -151,5 +156,4 @@ contract DelayedVetoable is Semver {
             return(0x0, returndatasize())
         }
     }
-    }
 }

packages/contracts-bedrock/test/DelayedVetoable.t.sol

@@ -130,20 +130,3 @@ contract DelayedVetoable_HandleCall_TestFail is DelayedVetoable_Init {
         assertFalse(success);
     }
 }
-
-contract DelayedVetoable_Veto_Test is DelayedVetoable_Init {
-    function test_veto_succeeds(bytes memory data) external {
-        vm.expectEmit(true, false, false, true, address(delayedVetoable));
-        emit Vetoed(keccak256(data), data);
-
-        vm.prank(vetoer);
-        delayedVetoable.veto(data);
-    }
-}
-
-contract DelayedVetoable_Veto_TestFail is DelayedVetoable_Init {
-    function test_veto_notVetoer_reverts() external {
-        vm.expectRevert();
-        delayedVetoable.veto(hex"");
-    }
-}