Added additional check on transform constructing (#109)

* Added check for execution results building

types/execution_result.go

@@ -94,12 +94,16 @@ func NewExecutionResultFromV1(v1 ExecutionResultV1) ExecutionResult {
 		for _, transform := range v1.Success.Effect.Transforms {
 			transforms = append(transforms, Transform{
 				Key:  transform.Key,
-				Kind: TransformKind(transform.Transform),
+				Kind: transform.Transform,
 			})
 		}
 
 		transfers := make([]Transfer, 0)
 		for _, transform := range v1.Success.Effect.Transforms {
+			if !transform.Transform.IsWriteTransfer() {
+				continue
+			}
+
 			writeTransfer, err := transform.Transform.ParseAsWriteTransfer()
 			if err != nil {
 				continue

types/transform.go

@@ -63,15 +63,19 @@ func (t *TransformKind) IsWriteTransfer() bool {
 
 func (t *TransformKind) ParseAsWriteTransfer() (*WriteTransfer, error) {
 	type RawWriteTransferTransform struct {
-		WriteTransfer `json:"WriteTransfer"`
+		WriteTransfer *WriteTransfer `json:"WriteTransfer"`
 	}
 
 	jsonRes := RawWriteTransferTransform{}
 	if err := json.Unmarshal(*t, &jsonRes); err != nil {
 		return nil, err
 	}
 
-	return &jsonRes.WriteTransfer, nil
+	if jsonRes.WriteTransfer == nil {
+		return nil, errors.New("error: empty response")
+	}
+
+	return jsonRes.WriteTransfer, nil
 }
 
 func (t *TransformKind) IsWriteAccount() bool {
@@ -298,15 +302,19 @@ func (t *TransformKind) ParseAsUInt512() (*clvalue.UInt512, error) {
 
 func (t *TransformKind) ParseAsWriteDeployInfo() (*DeployInfo, error) {
 	type RawWriteDeployInfo struct {
-		WriteDeployInfo DeployInfo `json:"WriteDeployInfo"`
+		WriteDeployInfo *DeployInfo `json:"WriteDeployInfo"`
 	}
 
 	jsonRes := RawWriteDeployInfo{}
 	if err := json.Unmarshal(*t, &jsonRes); err != nil {
 		return nil, err
 	}
 
-	return &jsonRes.WriteDeployInfo, nil
+	if jsonRes.WriteDeployInfo == nil {
+		return nil, errors.New("error: empty response")
+	}
+
+	return jsonRes.WriteDeployInfo, nil
 }
 
 func (t *TransformKind) ParseAsWriteCLValue() (*Argument, error) {