Merge branch 'main' into issue/52

src/RoboSaverVirtualModule.sol

@@ -232,7 +232,11 @@ contract RoboSaverVirtualModule {
     /// @return adjustPoolNeeded True if there is a deficit or surplus; false otherwise
     /// @return execPayload The payload of the needed transaction
     function checker() external view returns (bool adjustPoolNeeded, bytes memory execPayload) {
-        if (_isExternalTxQueued()) return (false, bytes("External transaction in queue, wait for it to be executed"));
+        /// @dev check if there is a transaction queued up in the delay module by an external entity
+        ///      and it is not yet expired
+        if (_isExternalTxQueued() && !_isCleanQueueRequired()) {
+            return (false, bytes("External transaction in queue, wait for it to be executed"));
+        }
 
         /// @dev check if there is a transaction queued up in the delay module by the virtual module itself
         if (queuedTx.nonce != 0) {
@@ -271,6 +275,7 @@ contract RoboSaverVirtualModule {
     /// @param _action The action to take: deposit or withdraw
     /// @param _amount The amount of $EURe to deposit or withdraw
     function adjustPool(PoolAction _action, uint256 _amount) external onlyKeeper {
+        if (_isCleanQueueRequired()) delayModule.skipExpired();
         if (_isExternalTxQueued()) revert ExternalTxIsQueued();
 
         if (_action == PoolAction.WITHDRAW) {
@@ -416,4 +421,16 @@ contract RoboSaverVirtualModule {
         /// @dev Requires deducting 1 from the storage nonce, since the delay module increments after writing timestamp in their internal storage
         if (block.timestamp - delayModule.getTxCreatedAt(_nonce - 1) <= delayModule.txCooldown()) isInCoolDown_ = true;
     }
+
+    /// @notice Check if any transactions are expired
+    /// @return anyExpiredTxs_ True if any transactions are expired; false otherwise
+    function _isCleanQueueRequired() internal view returns (bool anyExpiredTxs_) {
+        /// @dev Pick latest `txNonce` as reference to check if it is expired, then trigger clean-up
+        if (
+            block.timestamp - delayModule.getTxCreatedAt(delayModule.txNonce())
+                > delayModule.txCooldown() + delayModule.txExpiration()
+        ) {
+            anyExpiredTxs_ = true;
+        }
+    }
 }

test/AdjustPoolTest.t.sol

@@ -25,4 +25,32 @@ contract AdjustPoolTest is BaseFixture {
         vm.expectRevert(abi.encodeWithSelector(RoboSaverVirtualModule.ExternalTxIsQueued.selector));
         roboModule.adjustPool(RoboSaverVirtualModule.PoolAction.WITHDRAW, 5e18);
     }
+
+    function test_When_QueueHasExpiredTxs() public {
+        // 1. queue dummy transfer - external tx
+        _transferOutBelowThreshold();
+        uint256 txNonceBeforeCleanup = delayModule.txNonce(); // in this case should be `0`
+        assertEq(txNonceBeforeCleanup, 0);
+
+        (bool canExec, bytes memory execPayload) = roboModule.checker();
+
+        assertFalse(canExec);
+        assertEq(execPayload, bytes("External transaction in queue, wait for it to be executed"));
+
+        // 2. force queue to expire
+        skip(COOLDOWN_PERIOD + EXPIRATION_PERIOD + 1);
+
+        // @note that here it is returning `false` but not anymore external tx being queued as blocker
+        // since it is already on expired status
+        (canExec, execPayload) = roboModule.checker();
+        assertFalse(canExec);
+        assertEq(execPayload, bytes("Neither deficit nor surplus; no action needed"));
+
+        // 3. trigger a normal flow (includes cleanup + queuing of a deposit)
+        vm.prank(KEEPER);
+        roboModule.adjustPool(RoboSaverVirtualModule.PoolAction.DEPOSIT, 2e18);
+
+        // asserts the clean up its checked, since it triggered `txNonce++`
+        assertGt(delayModule.txNonce(), txNonceBeforeCleanup);
+    }
 }