rpc/request: return error from ExpandArrayIntoScript if any

Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>

pkg/rpc/request/txBuilder.go

@@ -97,7 +97,7 @@ func ExpandArrayIntoScript(script *io.BinWriter, slice []Param) error {
 			return fmt.Errorf("parameter type %v is not supported", fp.Type)
 		}
 	}
-	return nil
+	return script.Err
 }
 
 // CreateFunctionInvocationScript creates a script to invoke given contract with

pkg/rpc/request/tx_builder_test.go

@@ -135,6 +135,10 @@ func TestExpandArrayIntoScript(t *testing.T) {
 		{
 			{RawMessage: []byte(`{"type": "Array", "value": null}`)},
 		},
+		{
+			{RawMessage: []byte(`{"type": "Integer", "value": "` +
+				new(big.Int).Lsh(big.NewInt(1), 255).String() + `"}`)},
+		},
 	}
 	for _, c := range errorCases {
 		script := io.NewBufBinWriter()