From 80048f980883caa34fd4618814c83742eadc16ca Mon Sep 17 00:00:00 2001
From: Ermyas Abebe <ermyast@gmail.com>
Date: Thu, 5 Oct 2023 10:06:22 +1100
Subject: [PATCH] Add zero parameter value checks for MMR constructor

---
 src/MultiBridgeMessageReceiver.sol               | 10 +++++++++-
 test/unit-tests/MultiBridgeMessageReceiver.t.sol | 12 ++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/MultiBridgeMessageReceiver.sol b/src/MultiBridgeMessageReceiver.sol
index e9e0843..960b5ce 100644
--- a/src/MultiBridgeMessageReceiver.sol
+++ b/src/MultiBridgeMessageReceiver.sol
@@ -74,8 +74,16 @@ contract MultiBridgeMessageReceiver is IMultiBridgeMessageReceiver, ExecutorAwar
 
     /// @notice sets the initial parameters
     constructor(uint256 _srcChainId, address _gac) {
-        srcChainId = _srcChainId;
+        if (_gac == address(0)) {
+            revert Error.ZERO_ADDRESS_INPUT();
+        }
+
+        if (_srcChainId == 0) {
+            revert Error.INVALID_SENDER_CHAIN_ID();
+        }
+
         gac = IGAC(_gac);
+        srcChainId = _srcChainId;
     }
 
     /*/////////////////////////////////////////////////////////////////
diff --git a/test/unit-tests/MultiBridgeMessageReceiver.t.sol b/test/unit-tests/MultiBridgeMessageReceiver.t.sol
index ea2db45..f1b7e32 100644
--- a/test/unit-tests/MultiBridgeMessageReceiver.t.sol
+++ b/test/unit-tests/MultiBridgeMessageReceiver.t.sol
@@ -37,6 +37,18 @@ contract MultiBridgeMessageReceiverTest is Setup {
         timelockAddr = contractAddress[DST_CHAIN_ID]["TIMELOCK"];
     }
 
+    /// @dev cannot be called with zero source chain id
+    function test_constructor_zero_chain_id_input() public {
+        vm.expectRevert(Error.INVALID_SENDER_CHAIN_ID.selector);
+        new MultiBridgeMessageReceiver(0, address(42));
+    }
+
+    /// @dev cannot be called with zero address GAC
+    function test_constructor_zero_gac_address_input() public {
+        vm.expectRevert(Error.ZERO_ADDRESS_INPUT.selector);
+        new MultiBridgeMessageReceiver(1, address(0));
+    }
+
     /// @dev receives message from one adapter
     function test_receive_message() public {
         vm.startPrank(wormholeAdapterAddr);