Add Revert Reason to eth_call (#1829)

When an eth_call results in a revert report the call as an error with
the revert reason in the response, like we do with eth_estimateGas.

Signed-off-by: Danno Ferrin <danno.ferrin@gmail.com>

CHANGELOG.md

@@ -4,11 +4,13 @@
 
 ### 21.2 Breaking Changes
 * `--skip-pow-validation-enabled` is now an error with `block import --format JSON`. This is because the JSON format doesn't include the nonce so the proof of work must be calculated.
+* `eth_call` will not return a JSON-RPC result if the call fails, but will return an error instead. If it was for a revert the revert reason will be included.
 
 ### Additions and Improvements
 * Removed unused flags in default genesis configs [\#1812](https://github.com/hyperledger/besu/pull/1812)
 * `--skip-pow-validation-enabled` is now an error with `block import --format JSON`. This is because the JSON format doesn't include the nonce so the proof of work must be calculated. [\#1815](https://github.com/hyperledger/besu/pull/1815)
 * Added a new CLI option `--Xlauncher` to start a mainnet launcher. It will help to configure Besu easily.
+* Return the revert reason from `eth_call` JSON-RPC api calls when the contract causes a revert. [\#1829](https://github.com/hyperledger/besu/pull/1829)
  
 ### Bug Fixes
 * Ethereum classic heights will no longer be reported in mainnet metrics.  Issue [\#1751]((https://github.com/hyperledger/besu/pull/1751) Fix [\#1820](https://github.com/hyperledger/besu/pull/1820)

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthCall.java

@@ -20,12 +20,17 @@ import org.hyperledger.besu.ethereum.api.jsonrpc.internal.JsonRpcRequestContext;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.exception.InvalidJsonRpcParameters;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.parameters.BlockParameterOrBlockHash;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.parameters.JsonCallParameter;
+import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcError;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcErrorResponse;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcResponse;
 import org.hyperledger.besu.ethereum.api.jsonrpc.internal.response.JsonRpcSuccessResponse;
 import org.hyperledger.besu.ethereum.api.query.BlockchainQueries;
 import org.hyperledger.besu.ethereum.core.Hash;
+import org.hyperledger.besu.ethereum.mainnet.ValidationResult;
+import org.hyperledger.besu.ethereum.processing.TransactionProcessingResult;
+import org.hyperledger.besu.ethereum.transaction.TransactionInvalidReason;
 import org.hyperledger.besu.ethereum.transaction.TransactionSimulator;
+import org.hyperledger.besu.ethereum.transaction.TransactionSimulatorResult;
 
 public class EthCall extends AbstractBlockParameterOrBlockHashMethod {
   private final TransactionSimulator transactionSimulator;
@@ -59,8 +64,10 @@ public class EthCall extends AbstractBlockParameterOrBlockHashMethod {
                     .getValidationResult()
                     .either(
                         (() ->
-                            new JsonRpcSuccessResponse(
-                                request.getRequest().getId(), result.getOutput().toString())),
+                            result.isSuccessful()
+                                ? new JsonRpcSuccessResponse(
+                                    request.getRequest().getId(), result.getOutput().toString())
+                                : errorResponse(request, result)),
                         reason ->
                             new JsonRpcErrorResponse(
                                 request.getRequest().getId(),
@@ -77,6 +84,33 @@ public class EthCall extends AbstractBlockParameterOrBlockHashMethod {
     return new JsonRpcSuccessResponse(request.getRequest().getId(), null);
   }
 
+  private JsonRpcErrorResponse errorResponse(
+      final JsonRpcRequestContext request, final TransactionSimulatorResult result) {
+    final JsonRpcError jsonRpcError;
+
+    final ValidationResult<TransactionInvalidReason> validationResult =
+        result.getValidationResult();
+    if (validationResult != null && !validationResult.isValid()) {
+      jsonRpcError =
+          JsonRpcErrorConverter.convertTransactionInvalidReason(
+              validationResult.getInvalidReason());
+    } else {
+      final TransactionProcessingResult resultTrx = result.getResult();
+      if (resultTrx != null && resultTrx.getRevertReason().isPresent()) {
+        jsonRpcError = JsonRpcError.REVERT_ERROR;
+        jsonRpcError.setData(resultTrx.getRevertReason().get().toHexString());
+      } else {
+        jsonRpcError = JsonRpcError.INTERNAL_ERROR;
+      }
+    }
+    return errorResponse(request, jsonRpcError);
+  }
+
+  private JsonRpcErrorResponse errorResponse(
+      final JsonRpcRequestContext request, final JsonRpcError jsonRpcError) {
+    return new JsonRpcErrorResponse(request.getRequest().getId(), jsonRpcError);
+  }
+
   private JsonCallParameter validateAndGetCallParams(final JsonRpcRequestContext request) {
     final JsonCallParameter callParams = request.getRequiredParameter(0, JsonCallParameter.class);
     if (callParams.getTo() == null) {

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthCallTest.java

@@ -206,6 +206,7 @@ public class EthCallTest {
   private void mockTransactionProcessorSuccessResult(final Bytes output) {
     final TransactionSimulatorResult result = mock(TransactionSimulatorResult.class);
 
+    when(result.isSuccessful()).thenReturn(true);
     when(result.getValidationResult()).thenReturn(ValidationResult.valid());
     when(result.getOutput()).thenReturn(output);
     when(transactionSimulator.process(any(), any())).thenReturn(Optional.of(result));

ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/jsonrpc/eth_latest/eth_call_revert.json

@@ -0,0 +1,24 @@
+{
+  "request": {
+    "id": 3,
+    "jsonrpc": "2.0",
+    "method": "eth_call",
+    "params": [
+      {
+        "from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73",
+        "to": "0x0110000000000000000000000000000000000000"
+      },
+      "0x11"
+    ]
+  },
+  "response": {
+    "jsonrpc": "2.0",
+    "id": 3,
+    "error": {
+      "code": -32000,
+      "message": "Execution reverted",
+      "data": "0x7d88c1856cc95352"
+    }
+  },
+  "statusCode": 200
+}