return a new instance of Data in decodeSingleType

Sources/Web3Core/EthereumABI/ABIDecoding.swift

@@ -70,7 +70,7 @@ extension ABIDecoder {
         case .bytes(let length):
             guard elementItself.count >= 32 else {break}
             let dataSlice = elementItself[0 ..< length]
-            return (dataSlice, type.memoryUsage)
+            return (Data(dataSlice), type.memoryUsage)
         case .string:
             guard elementItself.count >= 32 else {break}
             var dataSlice = elementItself[0 ..< 32]
@@ -85,7 +85,7 @@ extension ABIDecoder {
             let length = UInt64(BigUInt(dataSlice))
             guard elementItself.count >= 32+length else {break}
             dataSlice = elementItself[32 ..< 32 + length]
-            return (dataSlice, nextElementPointer)
+            return (Data(dataSlice), nextElementPointer)
         case .array(type: let subType, length: let length):
             switch type.arraySize {
             case .dynamicSize:

Tests/web3swiftTests/localTests/ABIDecoderTests.swift

@@ -0,0 +1,42 @@
+//
+//  ABIDecoderTests.swift
+//
+//
+//  Created by liugang zhang on 2023/3/16.
+//
+
+import Foundation
+import Web3Core
+import XCTest
+import BigInt
+@testable import web3swift
+
+final class ABIDecoderTests: XCTestCase {
+
+    func testDecodeMulticall() throws {
+        let data = Data(hex: "0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000004fe6dab4abca350650")
+        let contract = try EthereumContract(Self.multiCall2, at: nil)
+        let erc20_balanceof = try EthereumContract(Web3.Utils.erc20ABI).methods["balanceOf"]!.first!
+        guard let decodedData = contract.decodeReturnData("tryAggregate", data: data) else {
+            throw Web3Error.processingError(desc: "Can not decode returned parameters")
+        }
+
+        guard let returnData = decodedData["returnData"] as? [[Any]] else {
+            throw Web3Error.dataError
+        }
+        var resultArray = [BigUInt]()
+        for i in 0..<2 {
+            guard let data = returnData[i][1] as? Data,
+                  let balance = erc20_balanceof.decodeReturnData(data)["0"] as? BigUInt else {
+                resultArray.append(0)
+                continue
+            }
+            resultArray.append(balance)
+        }
+        XCTAssert(resultArray.count == 2)
+    }
+}
+
+extension ABIDecoderTests {
+    public static let multiCall2 = "[{\"inputs\":[{\"components\":[{\"internalType\":\"address\",\"name\":\"target\",\"type\":\"address\"},{\"internalType\":\"bytes\",\"name\":\"callData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Call[]\",\"name\":\"calls\",\"type\":\"tuple[]\"}],\"name\":\"aggregate\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"blockNumber\",\"type\":\"uint256\"},{\"internalType\":\"bytes[]\",\"name\":\"returnData\",\"type\":\"bytes[]\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"components\":[{\"internalType\":\"address\",\"name\":\"target\",\"type\":\"address\"},{\"internalType\":\"bytes\",\"name\":\"callData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Call[]\",\"name\":\"calls\",\"type\":\"tuple[]\"}],\"name\":\"blockAndAggregate\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"blockNumber\",\"type\":\"uint256\"},{\"internalType\":\"bytes32\",\"name\":\"blockHash\",\"type\":\"bytes32\"},{\"components\":[{\"internalType\":\"bool\",\"name\":\"success\",\"type\":\"bool\"},{\"internalType\":\"bytes\",\"name\":\"returnData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Result[]\",\"name\":\"returnData\",\"type\":\"tuple[]\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"uint256\",\"name\":\"blockNumber\",\"type\":\"uint256\"}],\"name\":\"getBlockHash\",\"outputs\":[{\"internalType\":\"bytes32\",\"name\":\"blockHash\",\"type\":\"bytes32\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"getBlockNumber\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"blockNumber\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"getCurrentBlockCoinbase\",\"outputs\":[{\"internalType\":\"address\",\"name\":\"coinbase\",\"type\":\"address\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"getCurrentBlockDifficulty\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"difficulty\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"getCurrentBlockGasLimit\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"gaslimit\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"getCurrentBlockTimestamp\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"timestamp\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"address\",\"name\":\"addr\",\"type\":\"address\"}],\"name\":\"getEthBalance\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"balance\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"getLastBlockHash\",\"outputs\":[{\"internalType\":\"bytes32\",\"name\":\"blockHash\",\"type\":\"bytes32\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"bool\",\"name\":\"requireSuccess\",\"type\":\"bool\"},{\"components\":[{\"internalType\":\"address\",\"name\":\"target\",\"type\":\"address\"},{\"internalType\":\"bytes\",\"name\":\"callData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Call[]\",\"name\":\"calls\",\"type\":\"tuple[]\"}],\"name\":\"tryAggregate\",\"outputs\":[{\"components\":[{\"internalType\":\"bool\",\"name\":\"success\",\"type\":\"bool\"},{\"internalType\":\"bytes\",\"name\":\"returnData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Result[]\",\"name\":\"returnData\",\"type\":\"tuple[]\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"bool\",\"name\":\"requireSuccess\",\"type\":\"bool\"},{\"components\":[{\"internalType\":\"address\",\"name\":\"target\",\"type\":\"address\"},{\"internalType\":\"bytes\",\"name\":\"callData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Call[]\",\"name\":\"calls\",\"type\":\"tuple[]\"}],\"name\":\"tryBlockAndAggregate\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"blockNumber\",\"type\":\"uint256\"},{\"internalType\":\"bytes32\",\"name\":\"blockHash\",\"type\":\"bytes32\"},{\"components\":[{\"internalType\":\"bool\",\"name\":\"success\",\"type\":\"bool\"},{\"internalType\":\"bytes\",\"name\":\"returnData\",\"type\":\"bytes\"}],\"internalType\":\"struct Multicall2.Result[]\",\"name\":\"returnData\",\"type\":\"tuple[]\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"}]"
+}