✅ relocate MaliciousReceiver helper

test/Collateral.t.sol

@@ -4,6 +4,7 @@ pragma solidity 0.8.27;
 import {IEngine} from "src/interfaces/IEngine.sol";
 import {Bootstrap} from "test/utils/Bootstrap.sol";
 import {Pay} from "src/utils/Pay.sol";
+import {MaliciousReceiver} from "test/utils/MaliciousReceiver.sol";
 
 contract CollateralTest is Bootstrap {
     function setUp() public {
@@ -649,18 +650,3 @@ contract WithdrawCollateral is CollateralTest {
         vm.stopPrank();
     }
 }
-
-// Helper contract that rejects ETH transfers
-contract MaliciousReceiver {
-    receive() external payable {
-        revert();
-    }
-
-    function onERC721Received(address, address, uint256, bytes calldata)
-        external
-        pure
-        returns (bytes4)
-    {
-        return 0x150b7a02;
-    }
-}

test/Pay.t.sol

@@ -2,6 +2,7 @@
 pragma solidity 0.8.27;
 
 import {Bootstrap} from "test/utils/Bootstrap.sol";
+import {MaliciousReceiver} from "test/utils/MaliciousReceiver.sol";
 import {Pay} from "src/utils/Pay.sol";
 import {IWETH} from "src/interfaces/tokens/IWETH.sol";
 
@@ -91,19 +92,4 @@ contract PayTest is Bootstrap {
         payFork.unwrapAndPay(amount, to);
         assertEq(to.balance, balanceBefore + amount);
     }
-}
-
-// Helper contract that rejects ETH transfers
-contract MaliciousReceiver {
-    receive() external payable {
-        revert();
-    }
-
-    function onERC721Received(address, address, uint256, bytes calldata)
-        external
-        pure
-        returns (bytes4)
-    {
-        return 0x150b7a02;
-    }
-}
+}

test/utils/MaliciousReceiver.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity 0.8.27;
+
+/// @notice Helper contract that rejects ETH transfers
+/// @author cmontecoding
+contract MaliciousReceiver {
+    receive() external payable {
+        revert();
+    }
+
+    function onERC721Received(address, address, uint256, bytes calldata)
+        external
+        pure
+        returns (bytes4)
+    {
+        return 0x150b7a02;
+    }
+}