feat: fix rate limit for transferTokenLayerZero

Author: deluca-mike

src/libraries/LayerZeroLib.sol

@@ -4,6 +4,7 @@ pragma solidity ^0.8.21;
 import { ILayerZero, SendParam, OFTReceipt, MessagingFee } from "../interfaces/ILayerZero.sol";
 import { IRateLimits }                                     from "../interfaces/IRateLimits.sol";
 import { IALMProxy }                                       from "../interfaces/IALMProxy.sol";
+import { IERC20Like }                                      from "../interfaces/Common.sol";
 
 import { ApproveLib } from "./ApproveLib.sol";
 
@@ -12,7 +13,7 @@ import { OptionsBuilder } from "layerzerolabs/oapp-evm/contracts/oapp/libs/Optio
 library LayerZeroLib {
 
     using OptionsBuilder for bytes;
-    
+
     bytes32 public constant LIMIT_LAYERZERO_TRANSFER = keccak256("LIMIT_LAYERZERO_TRANSFER");
 
     /**********************************************************************************************/
@@ -27,61 +28,64 @@ library LayerZeroLib {
         uint32      destinationEndpointId,
         bytes32     layerZeroRecipient
     ) external {
-        _rateLimited(
-            rateLimits,
-            keccak256(
-                abi.encode(
-                    LIMIT_LAYERZERO_TRANSFER,
-                    oftAddress,
-                    destinationEndpointId
-                )
-            ),
-            amount
-        );
-
         require(layerZeroRecipient != bytes32(0), "MC/recipient-not-set");
 
+        address token = ILayerZero(oftAddress).token();
+
         // NOTE: Full integration testing of this logic is not possible without OFTs with
         //       approvalRequired == false. Add integration testing for this case before
         //       using in production.
         if (ILayerZero(oftAddress).approvalRequired()) {
-            ApproveLib.approve(
-                ILayerZero(oftAddress).token(),
-                address(proxy),
-                oftAddress,
-                amount
-            );
+            ApproveLib.approve(token, address(proxy), oftAddress, amount);
         }
 
-        bytes memory options = OptionsBuilder.newOptions().addExecutorLzReceiveOption(200_000, 0);
-
         SendParam memory sendParams = SendParam({
             dstEid       : destinationEndpointId,
             to           : layerZeroRecipient,
             amountLD     : amount,
             minAmountLD  : 0,
-            extraOptions : options,
+            extraOptions : OptionsBuilder.newOptions().addExecutorLzReceiveOption(200_000, 0),
             composeMsg   : "",
             oftCmd       : ""
         });
 
         // Query the min amount received on the destination chain and set it.
-        ( , , OFTReceipt memory receipt ) = ILayerZero(oftAddress).quoteOFT(sendParams);
-        sendParams.minAmountLD = receipt.amountReceivedLD;
+        sendParams.minAmountLD = _getQuotedAmountReceivedLD(oftAddress, sendParams);
 
         MessagingFee memory fee = ILayerZero(oftAddress).quoteSend(sendParams, false);
 
+        uint256 balanceBefore = IERC20Like(token).balanceOf(address(proxy));
+
         proxy.doCallWithValue{value: fee.nativeFee}(
             oftAddress,
             abi.encodeCall(ILayerZero.send, (sendParams, fee, address(proxy))),
             fee.nativeFee
         );
+
+        _rateLimited(
+            rateLimits,
+            keccak256(
+                abi.encode(
+                    LIMIT_LAYERZERO_TRANSFER,
+                    oftAddress,
+                    destinationEndpointId
+                )
+            ),
+            balanceBefore - IERC20Like(token).balanceOf(address(proxy))
+        );
     }
 
     /**********************************************************************************************/
-    /*** Rate Limit helper functions                                                            ***/
+    /*** Helper functions                                                                       ***/
     /**********************************************************************************************/
 
+    function _getQuotedAmountReceivedLD(address oftAddress, SendParam memory sendParams)
+        internal view returns (uint256)
+    {
+        ( , , OFTReceipt memory receipt ) = ILayerZero(oftAddress).quoteOFT(sendParams);
+        return receipt.amountReceivedLD;
+    }
+
     function _rateLimited(IRateLimits rateLimits, bytes32 key, uint256 amount) internal {
         rateLimits.triggerRateLimitDecrease(key, amount);
     }