reentrancy test

Author: LeoPatOZ

test/MessageRelayer/DepositRecipientScenarios.t.sol

@@ -3,6 +3,8 @@ pragma solidity ^0.8.28;
 
 import {GenericRecipient} from "./GenericRecipient.t.sol";
 import {InitialState} from "./InitialState.t.sol";
+
+import {IETHBridge} from "src/protocol/IETHBridge.sol";
 import {IMessageRelayer} from "src/protocol/IMessageRelayer.sol";
 
 // This is a concrete class because if we are not using the MessageRelayer,

test/MessageRelayer/FundAmountScenarios.t.sol

@@ -7,7 +7,7 @@ import {GenericRecipient} from "./GenericRecipient.t.sol";
 import {InitialState} from "./InitialState.t.sol";
 import {IETHBridge} from "src/protocol/IETHBridge.sol";
 
-contract VaryingFundAmount is DepositRecipientIsMessageRelayer {
+contract VaryingFundAmounts is DepositRecipientIsMessageRelayer {
     function setUp() public override {
         super.setUp();
     }

test/MessageRelayer/GenericRecipient.t.sol

@@ -1,17 +1,36 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.28;
 
-contract GenericRecipient {
+import {IMessageRelayer} from "src/protocol/IMessageRelayer.sol";
+
+interface IGenericRecipient {
+    function setSuccess(bool _callWillSucceed) external;
+    function setReentrancyAttack(bool _shouldAttack) external;
+}
+
+contract GenericRecipient is IGenericRecipient {
     bool private callWillSucceed = true;
+    bool private shouldReenterAttack = false;
+    address private relayer;
+    uint256 private reentrancyCounter = 0;
 
     error CallFailed();
 
     event FunctionCalled();
+    event ReentrancyAttempt(uint256 counter);
+
+    constructor(address _relayer) {
+        relayer = _relayer;
+    }
 
     function setSuccess(bool _callWillSucceed) external {
         callWillSucceed = _callWillSucceed;
     }
 
+    function setReentrancyAttack(bool _shouldAttack) external {
+        shouldReenterAttack = _shouldAttack;
+    }
+
     fallback() external payable {
         _simulateFunctionCall();
     }
@@ -23,5 +42,12 @@ contract GenericRecipient {
     function _simulateFunctionCall() internal {
         require(callWillSucceed, CallFailed());
         emit FunctionCalled();
+
+        if (shouldReenterAttack) {
+            reentrancyCounter++;
+            emit ReentrancyAttempt(reentrancyCounter);
+
+            IMessageRelayer(relayer).receiveMessage(address(this), 0, address(this), 0, "0x");
+        }
     }
 }

test/MessageRelayer/InitialState.t.sol

@@ -30,14 +30,15 @@ abstract contract InitialState is Test {
         MockSignalService signalService = new MockSignalService();
         address trustedCommitmentPublisher = _randomAddress("trustedCommitmentPublisher");
         address counterpart = _randomAddress("counterpart");
-        to = new GenericRecipient();
-        relayerSelectedTipRecipient = new GenericRecipient();
-        userSelectedTipRecipient = new GenericRecipient();
         ETHBridge bridge = new ETHBridge(address(signalService), trustedCommitmentPublisher, counterpart);
         vm.deal(address(bridge), amount);
 
         messageRelayer = new MessageRelayer(address(bridge));
 
+        to = new GenericRecipient(address(messageRelayer));
+        relayerSelectedTipRecipient = new GenericRecipient(address(messageRelayer));
+        userSelectedTipRecipient = new GenericRecipient(address(messageRelayer));
+
         ethDeposit = IETHBridge.ETHDeposit({
             nonce: 0,
             from: _randomAddress("from"),

test/MessageRelayer/RelayRecipientScenarios.t.sol

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.28;
+
+import {DepositRecipientIsMessageRelayer} from "./DepositRecipientScenarios.t.sol";
+import {GenericRecipient} from "./GenericRecipient.t.sol";
+
+import {InitialState} from "./InitialState.t.sol";
+import {IETHBridge} from "src/protocol/IETHBridge.sol";
+
+contract RelayRecipientRejectsDeposit is DepositRecipientIsMessageRelayer {
+    function setUp() public override {
+        super.setUp();
+        to.setSuccess(false);
+    }
+
+    function test_RelayRecipientRejectsDeposit_relayMessage_shouldRevert() public {
+        vm.expectRevert(IETHBridge.FailedClaim.selector);
+        _relayMessage();
+    }
+}
+
+contract RelayRecipientIsReentrant is DepositRecipientIsMessageRelayer {
+    function setUp() public override {
+        super.setUp();
+        to.setReentrancyAttack(true);
+    }
+
+    function test_RelayRecipientReentersReceiveMessage_relayMessage_shouldRevert() public {
+        vm.expectRevert(IETHBridge.FailedClaim.selector);
+        _relayMessage();
+    }
+}