Add exception field in invokeresult

src/RpcClient/Models/RpcInvokeResult.cs

@@ -18,12 +18,16 @@ public class RpcInvokeResult
 
         public string Tx { get; set; }
 
+        public string Exception { get; set; }
+
         public JObject ToJson()
         {
             JObject json = new JObject();
             json["script"] = Script;
             json["state"] = State;
             json["gasconsumed"] = GasConsumed;
+            if (!string.IsNullOrEmpty(Exception))
+                json["exception"] = Exception;
             try
             {
                 json["stack"] = new JArray(Stack.Select(p => p.ToJson()));
@@ -43,6 +47,8 @@ public static RpcInvokeResult FromJson(JObject json)
             invokeScriptResult.Script = json["script"].AsString();
             invokeScriptResult.State = json["state"].TryGetEnum<VM.VMState>();
             invokeScriptResult.GasConsumed = json["gasconsumed"].AsString();
+            if (json.ContainsProperty("exception"))
+                invokeScriptResult.Exception = json["exception"]?.AsString();
             try
             {
                 invokeScriptResult.Stack = ((JArray)json["stack"]).Select(p => Utility.StackItemFromJson(p)).ToArray();

src/RpcServer/RpcServer.SmartContract.cs

@@ -23,7 +23,7 @@ private class Signers : IVerifiable
         {
             private readonly Signer[] _signers;
             public Witness[] Witnesses { get; set; }
-            public int Size { get; }
+            public int Size => _signers.Length;
 
             public Signers(Signer[] signers)
             {
@@ -68,6 +68,7 @@ private JObject GetInvokeResult(byte[] script, Signers signers = null)
             json["script"] = Convert.ToBase64String(script);
             json["state"] = engine.State;
             json["gasconsumed"] = engine.GasConsumed.ToString();
+            json["exception"] = GetExceptionMessage(engine.FaultException);
             try
             {
                 json["stack"] = new JArray(engine.ResultStack.Select(p => p.ToJson()));
@@ -76,7 +77,10 @@ private JObject GetInvokeResult(byte[] script, Signers signers = null)
             {
                 json["stack"] = "error: recursive reference";
             }
-            ProcessInvokeWithWallet(json, signers);
+            if (engine.State != VMState.FAULT)
+            {
+                ProcessInvokeWithWallet(json, signers);
+            }
             return json;
         }
 
@@ -142,5 +146,17 @@ protected virtual JObject GetUnclaimedGas(JArray _params)
             json["address"] = script_hash.ToAddress();
             return json;
         }
+
+        static string GetExceptionMessage(Exception exception)
+        {
+            if (exception == null) return null;
+
+            if (exception.InnerException != null)
+            {
+                return exception.InnerException.Message;
+            }
+
+            return exception.Message;
+        }
     }
 }

src/RpcServer/RpcServer.Wallet.cs

@@ -174,7 +174,15 @@ private void ProcessInvokeWithWallet(JObject result, Signers signers = null)
                 UInt160 sender = signers.Size > 0 ? signers.GetSigners()[0].Account : null;
                 if (witnessSigners.Count() > 0)
                 {
-                    tx = wallet.MakeTransaction(Convert.FromBase64String(result["script"].AsString()), sender, witnessSigners);
+                    try
+                    {
+                        tx = wallet.MakeTransaction(result["script"].AsString().HexToBytes(), sender, witnessSigners);
+                    }
+                    catch (Exception e)
+                    {
+                        result["exception"] = GetExceptionMessage(e);
+                        return;
+                    }
                     ContractParametersContext context = new ContractParametersContext(tx);
                     wallet.Sign(context);
                     if (context.Completed)

tests/Neo.Network.RPC.Tests/UT_RpcClient.cs

@@ -277,6 +277,8 @@ public async Task TestInvokeFunction()
             var result = await rpc.InvokeFunctionAsync(test.Request.Params[0].AsString(), test.Request.Params[1].AsString(),
                 ((JArray)test.Request.Params[2]).Select(p => RpcStack.FromJson(p)).ToArray());
             Assert.AreEqual(test.Response.Result.ToString(), result.ToJson().ToString());
+
+            // TODO test verify method
         }
 
         [TestMethod]