problem: eth_simulateV1 returns an array, and there is no standard wa…

…y to handle this

solution: make RpcCall using JavaType instead of Class to support all types of data, including generics and arrays

etherjar-rpc-api/src/main/java/io/emeraldpay/etherjar/rpc/AbstractRpcTransport.java

@@ -15,6 +15,8 @@
  */
 package io.emeraldpay.etherjar.rpc;
 
+import com.fasterxml.jackson.databind.JavaType;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.*;
@@ -46,7 +48,7 @@ public CompletableFuture<Iterable<RpcCallResponse>> execute(List<DefaultBatch.Fu
             );
         }
         Map<Integer, DefaultBatch.FutureBatchItem> requests = new HashMap<>(items.size());
-        Map<Integer, Class> responseMapping = new HashMap<>(items.size());
+        Map<Integer, JavaType> responseMapping = new HashMap<>(items.size());
         List<RequestJson<Integer>> rpcRequests = items.stream()
             .map(item -> {
                 RequestJson<Integer> request = new RequestJson<>(
@@ -89,7 +91,7 @@ protected <JS, RES> Function<ResponseJson<?, Integer>, RpcCallResponse<JS, RES>>
         return (resp) -> {
             RpcCall<JS, RES> call = requests.get(resp.getId()).getCall();
             if (call != null) {
-                ResponseJson<JS, Integer> castResp = resp.cast(call.getJsonType());
+                ResponseJson<JS, Integer> castResp = resp.cast((Class<JS>) call.getJsonType().getRawClass());
                 return responseJsonConverter.convert(call, castResp);
             }
             return null;

etherjar-rpc-api/src/main/java/io/emeraldpay/etherjar/rpc/EthCommands.java

@@ -15,6 +15,8 @@
  */
 package io.emeraldpay.etherjar.rpc;
 
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.type.TypeFactory;
 import io.emeraldpay.etherjar.domain.*;
 import io.emeraldpay.etherjar.hex.Hex32;
 import io.emeraldpay.etherjar.hex.HexData;
@@ -23,6 +25,9 @@
 
 public class EthCommands {
 
+    private final JavaType blockWithTxJsonType = TypeFactory.defaultInstance().constructParametricType(BlockJson.class, TransactionJson.class);
+    private final JavaType blockWithTxIdType = TypeFactory.defaultInstance().constructParametricType(BlockJson.class, TransactionRefJson.class);
+
     private final Class<BlockJson<TransactionJson>> blockWithTxJson = getBlockWithTx();
     private final Class<BlockJson<TransactionRefJson>> blockWithTxId = getBlockWithRef();
 
@@ -73,7 +78,7 @@ public RpcCall<String, Wei> getBalance(Address address, long block) {
      */
     public RpcCall<BlockJson<TransactionRefJson>, BlockJson<TransactionRefJson>> getBlock(long blockNumber) {
         return RpcCall.create("eth_getBlockByNumber", blockWithTxId, HexQuantity.from(blockNumber).toHex(), false)
-            .withJsonType(blockWithTxId)
+            .withJsonType(blockWithTxIdType).castJsonType(blockWithTxId)
             .withResultType(blockWithTxId);
     }
 
@@ -85,7 +90,7 @@ public RpcCall<BlockJson<TransactionRefJson>, BlockJson<TransactionRefJson>> get
      */
     public RpcCall<BlockJson<TransactionJson>, BlockJson<TransactionJson>> getBlockWithTransactions(long blockNumber) {
         return RpcCall.create("eth_getBlockByNumber", blockWithTxJson, HexQuantity.from(blockNumber).toHex(), true)
-            .withJsonType(blockWithTxJson)
+            .withJsonType(blockWithTxJsonType).castJsonType(blockWithTxJson)
             .withResultType(blockWithTxJson);
     }
 
@@ -96,7 +101,7 @@ public RpcCall<BlockJson<TransactionJson>, BlockJson<TransactionJson>> getBlockW
      */
     public RpcCall<BlockJson<TransactionRefJson>, BlockJson<TransactionRefJson>> getBlock(BlockHash hash) {
         return RpcCall.create("eth_getBlockByHash", blockWithTxId, hash.toHex(), false)
-            .withJsonType(blockWithTxId)
+            .withJsonType(blockWithTxIdType).castJsonType(blockWithTxId)
             .withResultType(blockWithTxId);
     }
 
@@ -107,7 +112,7 @@ public RpcCall<BlockJson<TransactionRefJson>, BlockJson<TransactionRefJson>> get
      */
     public RpcCall<BlockJson<TransactionJson>, BlockJson<TransactionJson>> getBlockWithTransactions(BlockHash hash) {
         return RpcCall.create("eth_getBlockByHash", blockWithTxJson, hash.toHex(), true)
-            .withJsonType(blockWithTxJson)
+            .withJsonType(blockWithTxJsonType).castJsonType(blockWithTxJson)
             .withResultType(blockWithTxJson);
     }
 
@@ -355,8 +360,8 @@ public RpcCall<String, HexData> call(TransactionCallJson call, BlockTag block) {
      * @param block The simulated blocks will be built on top of this. If null, the current block is used.
      * @return simulated block
      */
-    public RpcCall<BlockSimulatedJson, BlockSimulatedJson> simulateV1(SimulateJson payload, BlockTag block) {
-        return RpcCall.create("eth_simulateV1", BlockSimulatedJson.class, payload, block.getCode());
+    public RpcCall<BlockSimulatedJson[], BlockSimulatedJson[]> simulateV1(SimulateJson payload, BlockTag block) {
+        return RpcCall.create("eth_simulateV1", BlockSimulatedJson.class, payload, block.getCode()).asArray();
     }
 
     /**

etherjar-rpc-api/src/main/java/io/emeraldpay/etherjar/rpc/ParityCommands.java

@@ -16,6 +16,7 @@
 package io.emeraldpay.etherjar.rpc;
 
 import io.emeraldpay.etherjar.domain.TransactionId;
+import io.emeraldpay.etherjar.rpc.json.TraceItemJson;
 
 /**
  * Commands specific for Parity Ethereum
@@ -28,7 +29,7 @@ public class ParityCommands {
      * @param hash hash of the transaction
      * @return trace list
      */
-    public RpcCall<TraceList, TraceList> traceTransaction(TransactionId hash) {
-        return RpcCall.create("trace_transaction", TraceList.class, hash.toHex());
+    public RpcCall<TraceItemJson[], TraceItemJson[]> traceTransaction(TransactionId hash) {
+        return RpcCall.create("trace_transaction", TraceItemJson.class, hash.toHex()).asArray();
     }
 }