Merge pull request #135 from PartyDAO/feat/refund-leftover-eth

feat(`ArbitraryCallsProposal`): refund leftover ETH
PartyDAO · Sep 22, 2022 · 1562f44 · 1562f44
2 parents 62c3b1c + abcad82
commit 1562f44
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diff --git a/contracts/proposals/ArbitraryCallsProposal.sol b/contracts/proposals/ArbitraryCallsProposal.sol
@@ -5,6 +5,7 @@ pragma solidity ^0.8;
 import "../tokens/IERC721.sol";
 import "../tokens/IERC721Receiver.sol";
 import "../utils/LibSafeERC721.sol";
+import "../utils/LibAddress.sol";
 
 import "./LibProposal.sol";
 import "./IProposalExecutionEngine.sol";
@@ -13,6 +14,7 @@ import "./IProposalExecutionEngine.sol";
 // This contract will be delegatecall'ed into by `Party` proxy instances.
 contract ArbitraryCallsProposal {
     using LibSafeERC721 for IERC721;
+    using LibAddress for address payable;
 
     struct ArbitraryCall {
         // The call target.
@@ -87,6 +89,10 @@ contract ArbitraryCallsProposal {
                 }
             }
         }
+        // Refund leftover ETH.
+        if (ethAvailable > 0) {
+            payable(msg.sender).transferEth(ethAvailable);
+        }
         // No next step, so no progressData.
         return '';
     }

diff --git a/sol-tests/proposals/ArbitraryCallsProposal.t.sol b/sol-tests/proposals/ArbitraryCallsProposal.t.sol
@@ -249,6 +249,27 @@ contract ArbitraryCallsProposalTest is
         testContract.execute{ value: 1.5e18 }(prop);
     }
 
+    function test_canExecuteCallWithEth_refundsLeftover() external {
+        (
+            ArbitraryCallsProposal.ArbitraryCall[] memory calls,
+            bytes32[] memory callArgs
+        ) = _createSimpleCalls(1, false);
+        calls[0].value = 1e18;
+        IProposalExecutionEngine.ExecuteProposalParams memory prop =
+            _createTestProposal(calls);
+        for (uint256 i = 0; i < calls.length; ++i) {
+            _expectNonIndexedEmit();
+            emit ArbitraryCallTargetSuccessCalled(address(testContract), calls[i].value, callArgs[i]);
+            _expectNonIndexedEmit();
+            emit ArbitraryCallExecuted(prop.proposalId, i, calls.length);
+        }
+        uint256 balanceBefore = address(this).balance;
+        testContract.execute{ value: 2e18 }(prop);
+        uint256 balanceAfter = address(this).balance;
+        // Spent 2 ETH, refunded 1 ETH
+        assertEq(balanceBefore - balanceAfter, 1e18);
+    }
+
     function test_cannotConsumeMoreEthThanAttachedWithSingleCall() external {
         (
             ArbitraryCallsProposal.ArbitraryCall[] memory calls,
@@ -565,4 +586,7 @@ contract ArbitraryCallsProposalTest is
             mstore(data, sub(mload(data), bytesFromEnd))
         }
     }
+
+    // To receive ETH refunds
+    receive() external payable {}
 }