From d9661135a1938c187d647ad22c7a6741d90d720a Mon Sep 17 00:00:00 2001
From: wirew0lf <wirew0lf@wirew0lf.com>
Date: Wed, 20 Mar 2024 17:44:06 +0100
Subject: [PATCH] Add Transfer With Caller function

---
 CCTPRelayer/src/CCTPRelayer.sol    | 25 +++++++++++++++++++
 CCTPRelayer/test/CCTPRelayer.t.sol | 39 ++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/CCTPRelayer/src/CCTPRelayer.sol b/CCTPRelayer/src/CCTPRelayer.sol
index 802cdb7..515f6d4 100644
--- a/CCTPRelayer/src/CCTPRelayer.sol
+++ b/CCTPRelayer/src/CCTPRelayer.sol
@@ -64,6 +64,31 @@ contract CCTPRelayer is ICCTPRelayer, Initializable, UUPSUpgradeable, Ownable2St
         emit PaymentForRelay(nonce, feeAmount);
     }
 
+    function requestCCTPTransferWithCaller(
+        uint256 transferAmount,
+        uint32 destinationDomain,
+        bytes32 mintRecipient,
+        address burnToken,
+        uint256 feeAmount,
+        bytes32 destinationCaller
+    ) external {
+        if (transferAmount == 0) revert PaymentCannotBeZero();
+        if (feeAmount == 0) revert PaymentCannotBeZero();
+        // In order to save gas do the transfer only once, of both transfer amount and fee amount.
+        if (!usdc.transferFrom(msg.sender, address(this), transferAmount + feeAmount)) revert TransferFailed();
+
+        // Only give allowance of the transfer amount, as we want the fee amount to stay in the contract.
+        usdc.approve(address(messenger), transferAmount);
+
+        // Call deposit for burn and save the nonce.
+        uint64 nonce = messenger.depositForBurnWithCaller(
+            transferAmount, destinationDomain, mintRecipient, burnToken, destinationCaller
+        );
+
+        // As user already paid for the fee we emit the payment event.
+        emit PaymentForRelay(nonce, feeAmount);
+    }
+
     function batchReceiveMessage(ICCTPRelayer.ReceiveCall[] memory receiveCalls) external {
         // Save gas by not retrieving the length on each loop.
         uint256 length = receiveCalls.length;
diff --git a/CCTPRelayer/test/CCTPRelayer.t.sol b/CCTPRelayer/test/CCTPRelayer.t.sol
index 5325bfc..9ef1698 100644
--- a/CCTPRelayer/test/CCTPRelayer.t.sol
+++ b/CCTPRelayer/test/CCTPRelayer.t.sol
@@ -145,6 +145,23 @@ contract CCTPRelayerTest is Test {
         }
     }
 
+    function test_requestCCTPTransferWithCaller() public {
+        uint256 length = forks.length;
+
+        uint32[6] memory domains = [uint32(7), 6, 3, 2, 1, 0];
+
+        for (uint256 i; i < length; ++i) {
+            uint32 domain;
+            if (i < 6) {
+                domain = domains[i];
+            } else {
+                domain = domains[i - 6];
+            }
+            _switchFork(forks[i]);
+            _requestCCTPTransferWithCaller(domain);
+        }
+    }
+
     function test_withdraw() public {
         uint256 length = forks.length;
 
@@ -180,6 +197,28 @@ contract CCTPRelayerTest is Test {
         assertEq(usdc.balanceOf(ACTOR_1), 0, "Balance Remaining After Payment");
     }
 
+    function _requestCCTPTransferWithCaller(uint32 domain) internal {
+        uint256 transferAmount = 1_000 * 1e6;
+        uint256 feeAmount = 10 * 1e6;
+        uint256 amount = transferAmount + feeAmount;
+
+        _dealUSDC(ACTOR_1, amount);
+        assertEq(usdc.balanceOf(ACTOR_1), amount, "Balance Before Payment is Wrong");
+
+        bytes32 mintRecipent = bytes32(abi.encodePacked(ACTOR_1));
+
+        vm.startPrank(ACTOR_1);
+        usdc.approve(address(relayer), amount);
+        relayer.requestCCTPTransferWithCaller(
+            transferAmount, domain, mintRecipent, address(usdc), feeAmount, keccak256(abi.encodePacked("random caller"))
+        );
+        vm.stopPrank();
+
+        assertEq(usdc.allowance(address(relayer), address(messenger)), 0, "Messenger Allowance Remaining After Payment");
+        assertEq(usdc.allowance(ACTOR_1, address(relayer)), 0, "Relayer Allowance Remaining After Payment");
+        assertEq(usdc.balanceOf(ACTOR_1), 0, "Balance Remaining After Payment");
+    }
+
     function _switchFork(uint256 id) internal {
         vm.selectFork(id);