Optimize Address.functionCall removing redundant isContract check

contracts/mocks/crosschain/bridges.sol

@@ -22,7 +22,7 @@ abstract contract BaseRelayMock {
         _currentSender = sender;
 
         (bool success, bytes memory returndata) = target.call(data);
-        Address.verifyCallResult(success, returndata, "low-level call reverted");
+        Address.verifyCallResult(target, success, returndata, "low-level call reverted");
 
         _currentSender = previousSender;
     }

contracts/utils/Address.sol

@@ -132,10 +132,8 @@ library Address {
         string memory errorMessage
     ) internal returns (bytes memory) {
         require(address(this).balance >= value, "Address: insufficient balance for call");
-        require(isContract(target), "Address: call to non-contract");
-
         (bool success, bytes memory returndata) = target.call{value: value}(data);
-        return verifyCallResult(success, returndata, errorMessage);
+        return verifyCallResult(target, success, returndata, errorMessage);
     }
 
     /**
@@ -159,10 +157,8 @@ library Address {
         bytes memory data,
         string memory errorMessage
     ) internal view returns (bytes memory) {
-        require(isContract(target), "Address: static call to non-contract");
-
         (bool success, bytes memory returndata) = target.staticcall(data);
-        return verifyCallResult(success, returndata, errorMessage);
+        return verifyCallResult(target, success, returndata, errorMessage);
     }
 
     /**
@@ -186,10 +182,8 @@ library Address {
         bytes memory data,
         string memory errorMessage
     ) internal returns (bytes memory) {
-        require(isContract(target), "Address: delegate call to non-contract");
-
         (bool success, bytes memory returndata) = target.delegatecall(data);
-        return verifyCallResult(success, returndata, errorMessage);
+        return verifyCallResult(target, success, returndata, errorMessage);
     }
 
     /**
@@ -198,6 +192,24 @@ library Address {
      *
      * _Available since v4.3._
      */
+    function verifyCallResult(
+        address target,
+        bool success,
+        bytes memory returndata,
+        string memory errorMessage
+    ) internal view returns (bytes memory) {
+        if (success) {
+            if (returndata.length == 0) {
+                // only check isContract if the call was successful and the return data is empty
+                // otherwise we already know that it was a contract
+                require(isContract(target), "Address: call to non-contract");
+            }
+            return returndata;
+        } else {
+            _revert(returndata, errorMessage);
+        }
+    }
+
     function verifyCallResult(
         bool success,
         bytes memory returndata,
@@ -206,17 +218,21 @@ library Address {
         if (success) {
             return returndata;
         } else {
-            // Look for revert reason and bubble it up if present
-            if (returndata.length > 0) {
-                // The easiest way to bubble the revert reason is using memory via assembly
-                /// @solidity memory-safe-assembly
-                assembly {
-                    let returndata_size := mload(returndata)
-                    revert(add(32, returndata), returndata_size)
-                }
-            } else {
-                revert(errorMessage);
+            _revert(returndata, errorMessage);
+        }
+    }
+
+    function _revert(bytes memory returndata, string memory errorMessage) private pure {
+        // Look for revert reason and bubble it up if present
+        if (returndata.length > 0) {
+            // The easiest way to bubble the revert reason is using memory via assembly
+            /// @solidity memory-safe-assembly
+            assembly {
+                let returndata_size := mload(returndata)
+                revert(add(32, returndata), returndata_size)
             }
+        } else {
+            revert(errorMessage);
         }
     }
 }

test/utils/Address.test.js

@@ -143,7 +143,7 @@ contract('Address', function (accounts) {
         }, []);
 
         await expectRevert(
-          this.mock.functionCall(this.contractRecipient.address, abiEncodedCall, { gas: '100000' }),
+          this.mock.functionCall(this.contractRecipient.address, abiEncodedCall, { gas: '120000' }),
           'Address: low-level call failed',
         );
       });
@@ -329,7 +329,7 @@ contract('Address', function (accounts) {
       }, []);
       await expectRevert(
         this.mock.functionStaticCall(recipient, abiEncodedCall),
-        'Address: static call to non-contract',
+        'Address: call to non-contract',
       );
     });
   });
@@ -375,7 +375,7 @@ contract('Address', function (accounts) {
       }, []);
       await expectRevert(
         this.mock.functionDelegateCall(recipient, abiEncodedCall),
-        'Address: delegate call to non-contract',
+        'Address: call to non-contract',
       );
     });
   });