test(ctb): bridge return to sender on fail (#3041)

Adds a test that bridge contracts return to sender on failed deposits or
withdrawals.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

packages/contracts-bedrock/.gas-snapshot

@@ -49,19 +49,20 @@ L1CrossDomainMessenger_Test:test_L1MessengerSendMessage() (gas: 297745)
 L1CrossDomainMessenger_Test:test_L1MessengerTwiceSendMessage() (gas: 1490048)
 L1CrossDomainMessenger_Test:test_L1MessengerUnpause() (gas: 40908)
 L1CrossDomainMessenger_Test:test_L1MessengerXDomainSenderReverts() (gas: 24249)
-L1CrossDomainMessenger_Test:test_L1MessengerxDomainMessageSenderResets() (gas: 86191)
-L1StandardBridge_Test:test_depositERC20() (gas: 578867)
-L1StandardBridge_Test:test_depositERC20To() (gas: 581048)
-L1StandardBridge_Test:test_depositETH() (gas: 372975)
+L1CrossDomainMessenger_Test:test_L1MessengerxDomainMessageSenderResets() (gas: 86168)
+L1StandardBridge_Test:test_depositERC20() (gas: 578911)
+L1StandardBridge_Test:test_depositERC20To() (gas: 581092)
+L1StandardBridge_Test:test_depositETH() (gas: 372953)
 L1StandardBridge_Test:test_depositETHTo() (gas: 330097)
-L1StandardBridge_Test:test_finalizeERC20Withdrawal() (gas: 490759)
-L1StandardBridge_Test:test_finalizeETHWithdrawal() (gas: 64409)
-L1StandardBridge_Test:test_initialize() (gas: 26336)
-L1StandardBridge_Test:test_onlyEOADepositERC20() (gas: 22363)
-L1StandardBridge_Test:test_onlyEOADepositETH() (gas: 40816)
-L1StandardBridge_Test:test_onlyL2BridgeFinalizeERC20Withdrawal() (gas: 36271)
-L1StandardBridge_Test:test_onlyPortalFinalizeERC20Withdrawal() (gas: 35600)
-L1StandardBridge_Test:test_receive() (gas: 519560)
+L1StandardBridge_Test:test_finalizeBridgeERC20FailSendBack() (gas: 681339)
+L1StandardBridge_Test:test_finalizeERC20Withdrawal() (gas: 490817)
+L1StandardBridge_Test:test_finalizeETHWithdrawal() (gas: 64453)
+L1StandardBridge_Test:test_initialize() (gas: 26401)
+L1StandardBridge_Test:test_onlyEOADepositERC20() (gas: 22341)
+L1StandardBridge_Test:test_onlyEOADepositETH() (gas: 40882)
+L1StandardBridge_Test:test_onlyL2BridgeFinalizeERC20Withdrawal() (gas: 36294)
+L1StandardBridge_Test:test_onlyPortalFinalizeERC20Withdrawal() (gas: 35578)
+L1StandardBridge_Test:test_receive() (gas: 519538)
 L2CrossDomainMessenger_Test:testCannot_L2MessengerPause() (gas: 10823)
 L2CrossDomainMessenger_Test:test_L1MessengerRelayMessageRevertsOnReentrancy() (gas: 171968)
 L2CrossDomainMessenger_Test:test_L2MessengerMessageVersion() (gas: 8455)
@@ -99,12 +100,13 @@ L2OutputOracleUpgradeable_Test:test_initValuesOnProxy() (gas: 38899)
 L2OutputOracleUpgradeable_Test:test_upgrading() (gas: 230843)
 L2StandardBridge_Test:test_ERC20BridgeFailed_whenLocalTokenIsBridge() (gas: 133459)
 L2StandardBridge_Test:test_cannotWithdrawEthWithoutSendingIt() (gas: 21656)
+L2StandardBridge_Test:test_finalizeBridgeERC20FailSendBack() (gas: 499042)
 L2StandardBridge_Test:test_finalizeDeposit() (gas: 93203)
-L2StandardBridge_Test:test_finalizeDeposit_failsToCompleteOutboundTransfer() (gas: 140469)
+L2StandardBridge_Test:test_finalizeDeposit_failsToCompleteOutboundTransfer() (gas: 140492)
 L2StandardBridge_Test:test_initialize() (gas: 14802)
 L2StandardBridge_Test:test_receive() (gas: 136864)
-L2StandardBridge_Test:test_withdraw() (gas: 353020)
-L2StandardBridge_Test:test_withdrawTo() (gas: 353705)
+L2StandardBridge_Test:test_withdraw() (gas: 353022)
+L2StandardBridge_Test:test_withdrawTo() (gas: 353706)
 L2StandardBridge_Test:test_withdraw_onlyEOA() (gas: 252006)
 L2ToL1MessagePasserTest:test_burn() (gas: 112037)
 L2ToL1MessagePasserTest:test_initiateWithdrawal_fromContract() (gas: 67892)

packages/contracts-bedrock/contracts/test/CommonTest.t.sol

@@ -228,8 +228,10 @@ contract Bridge_Initializer is Messenger_Initializer {
     OptimismMintableERC20Factory L2TokenFactory;
     OptimismMintableERC20Factory L1TokenFactory;
     ERC20 L1Token;
+    ERC20 BadL1Token;
     OptimismMintableERC20 L2Token;
     ERC20 NativeL2Token;
+    ERC20 BadL2Token;
     OptimismMintableERC20 RemoteL1Token;
 
     event ETHDepositInitiated(
@@ -387,6 +389,14 @@ contract Bridge_Initializer is Messenger_Initializer {
             )
         );
 
+        BadL2Token = OptimismMintableERC20(
+            L2TokenFactory.createStandardL2Token(
+                address(1),
+                string(abi.encodePacked("L2-", L1Token.name())),
+                string(abi.encodePacked("L2-", L1Token.symbol()))
+            )
+        );
+
         NativeL2Token = new ERC20("Native L2 Token", "L2T");
         L1TokenFactory = new OptimismMintableERC20Factory(address(L1Bridge));
 
@@ -397,6 +407,14 @@ contract Bridge_Initializer is Messenger_Initializer {
                 string(abi.encodePacked("L1-", NativeL2Token.symbol()))
             )
         );
+
+        BadL1Token = OptimismMintableERC20(
+            L1TokenFactory.createStandardL2Token(
+                address(1),
+                string(abi.encodePacked("L1-", NativeL2Token.name())),
+                string(abi.encodePacked("L1-", NativeL2Token.symbol()))
+            )
+        );
     }
 }
 

packages/contracts-bedrock/contracts/test/L1StandardBridge.t.sol

@@ -391,4 +391,48 @@ contract L1StandardBridge_Test is Bridge_Initializer {
             hex""
         );
     }
+
+    function test_finalizeBridgeERC20FailSendBack() external {
+        deal(address(BadL1Token), address(L1Bridge), 100, true);
+
+        uint256 slot = stdstore
+            .target(address(L1Bridge))
+            .sig("deposits(address,address)")
+            .with_key(address(BadL1Token))
+            .with_key(address(L2Token))
+            .find();
+
+        // Give the L1 bridge some ERC20 tokens
+        vm.store(address(L1Bridge), bytes32(slot), bytes32(uint256(100)));
+        assertEq(L1Bridge.deposits(address(BadL1Token), address(L2Token)), 100);
+
+        vm.expectEmit(true, true, true, true);
+
+        emit ERC20BridgeInitiated(
+            address(BadL1Token),
+            address(L2Token),
+            bob,
+            alice,
+            100,
+            hex""
+        );
+
+        vm.mockCall(
+            address(L1Bridge.messenger()),
+            abi.encodeWithSelector(CrossDomainMessenger.xDomainMessageSender.selector),
+            abi.encode(address(L1Bridge.otherBridge()))
+        );
+        vm.prank(address(L1Bridge.messenger()));
+        L1Bridge.finalizeBridgeERC20(
+            address(BadL1Token),
+            address(L2Token),
+            alice,
+            bob,
+            100,
+            hex""
+        );
+
+        assertEq(BadL1Token.balanceOf(address(L1Bridge)), 100);
+        assertEq(BadL1Token.balanceOf(address(alice)), 0);
+    }
 }

packages/contracts-bedrock/contracts/test/L2StandardBridge.t.sol

@@ -197,5 +197,48 @@ contract L2StandardBridge_Test is Bridge_Initializer {
         vm.prank(address(L2Messenger));
         L2Bridge.finalizeDeposit(address(L1Token), address(L2Bridge), alice, bob, 100, hex"");
     }
-}
 
+    function test_finalizeBridgeERC20FailSendBack() external {
+        deal(address(BadL2Token), address(L2Bridge), 100, true);
+
+        uint256 slot = stdstore
+            .target(address(L2Bridge))
+            .sig("deposits(address,address)")
+            .with_key(address(BadL2Token))
+            .with_key(address(L1Token))
+            .find();
+
+        // Give the L2 bridge some ERC20 tokens
+        vm.store(address(L2Bridge), bytes32(slot), bytes32(uint256(100)));
+        assertEq(L2Bridge.deposits(address(BadL2Token), address(L1Token)), 100);
+
+        vm.expectEmit(true, true, true, true);
+
+        emit ERC20BridgeInitiated(
+            address(BadL2Token),
+            address(L1Token),
+            bob,
+            alice,
+            100,
+            hex""
+        );
+
+        vm.mockCall(
+            address(L2Bridge.messenger()),
+            abi.encodeWithSelector(CrossDomainMessenger.xDomainMessageSender.selector),
+            abi.encode(address(L2Bridge.otherBridge()))
+        );
+        vm.prank(address(L2Bridge.messenger()));
+        L2Bridge.finalizeBridgeERC20(
+            address(BadL2Token),
+            address(L1Token),
+            alice,
+            bob,
+            100,
+            hex""
+        );
+
+        assertEq(BadL2Token.balanceOf(address(L2Bridge)), 100);
+        assertEq(BadL2Token.balanceOf(address(alice)), 0);
+    }
+}

packages/contracts-bedrock/contracts/test/OptimismMintableERC20Factory.t.sol

@@ -22,7 +22,7 @@ contract OptimismMintableTokenFactory_Test is Bridge_Initializer {
 
     function test_createStandardL2Token() external {
         address remote = address(4);
-        address local = LibRLP.computeAddress(address(L2TokenFactory), 1);
+        address local = LibRLP.computeAddress(address(L2TokenFactory), 2);
 
         vm.expectEmit(true, true, true, true);
         emit StandardL2TokenCreated(
@@ -47,7 +47,7 @@ contract OptimismMintableTokenFactory_Test is Bridge_Initializer {
         vm.prank(alice);
         L2TokenFactory.createStandardL2Token(remote, "Beep", "BOOP");
 
-        address local = LibRLP.computeAddress(address(L2TokenFactory), 2);
+        address local = LibRLP.computeAddress(address(L2TokenFactory), 3);
 
         vm.expectEmit(true, true, true, true);
         emit StandardL2TokenCreated(