require relayer fee transfer success (#117)

Author: axchu

contracts/optimistic-ethereum/OVM/accounts/OVM_ECDSAContractAccount.sol

@@ -87,11 +87,15 @@ contract OVM_ECDSAContractAccount is iOVM_ECDSAContractAccount {
         // Transfer fee to relayer.
         address relayer = Lib_SafeExecutionManagerWrapper.safeCALLER();
         uint256 fee = decodedTx.gasLimit * decodedTx.gasPrice;
-        Lib_SafeExecutionManagerWrapper.safeCALL(
+        (bool success, ) = Lib_SafeExecutionManagerWrapper.safeCALL(
             gasleft(),
             ETH_ERC20_ADDRESS,
             abi.encodeWithSignature("transfer(address,uint256)", relayer, fee)
         );
+        Lib_SafeExecutionManagerWrapper.safeREQUIRE(
+            success == true,
+            "Fee was not transferred to relayer."
+        );
 
         // Contract creations are signalled by sending a transaction to the zero address.
         if (decodedTx.to == address(0)) {

test/contracts/OVM/accounts/OVM_ECDSAContractAccount.spec.ts

@@ -269,5 +269,31 @@ describe('OVM_ECDSAContractAccount', () => {
         'Gas is not sufficient to execute the transaction.'
       )
     })
+
+    it(`should revert if fee is not transferred to the relayer`, async () => {
+      const message = serializeNativeTransaction(DEFAULT_EIP155_TX)
+      const sig = await signNativeTransaction(wallet, DEFAULT_EIP155_TX)
+      Mock__OVM_ExecutionManager.smocked.ovmCALL.will.return.with([false, '0x'])
+
+      await callPrecompile(
+        Helper_PrecompileCaller,
+        OVM_ECDSAContractAccount,
+        'execute',
+        [
+          message,
+          0, //isEthSignedMessage
+          `0x${sig.v}`, //v
+          `0x${sig.r}`, //r
+          `0x${sig.s}`, //s
+        ],
+        40000000
+      )
+
+      const ovmREVERT: any =
+        Mock__OVM_ExecutionManager.smocked.ovmREVERT.calls[0]
+      expect(ethers.utils.toUtf8String(ovmREVERT._data)).to.equal(
+        'Fee was not transferred to relayer.'
+      )
+    })
   })
 })