- ABIDecoding getting data slice in followTheData changed to using start data index

Sources/Web3Core/Contract/ContractProtocol.swift

@@ -210,8 +210,8 @@ extension ContractProtocol {
 
     func decodeInputData(_ data: Data) -> [String: Any]? {
         guard data.count >= 4 else { return nil }
-        let methodId = data[0..<4].toHexString()
-        let data = data[4...]
+        let methodId = data[data.indices.startIndex ..< data.indices.startIndex + 4].toHexString()
+        let data = data[(data.indices.startIndex + 4)...]
         return decodeInputData(methodId, data: data)
     }
 }
@@ -333,14 +333,14 @@ extension DefaultContractProtocol {
 
     public func decodeInputData(_ data: Data) -> [String: Any]? {
         guard data.count % 32 == 4 else { return nil }
-        let methodSignature = data[0..<4].toHexString().addHexPrefix().lowercased()
+        let methodSignature = data[data.indices.startIndex ..< data.indices.startIndex + 4].toHexString().addHexPrefix().lowercased()
 
         guard let function = methods[methodSignature]?.first else { return nil }
-        return function.decodeInputData(Data(data[4 ..< data.count]))
+        return function.decodeInputData(Data(data[data.indices.startIndex + 4 ..< data.indices.startIndex + data.count]))
     }
 
     public func getFunctionCalled(_ data: Data) -> ABI.Element.Function? {
         guard data.count >= 4 else { return nil }
-        return methods[data[0..<4].toHexString().addHexPrefix()]?.first
+        return methods[data[data.indices.startIndex ..< data.indices.startIndex + 4].toHexString().addHexPrefix()]?.first
     }
 }

Sources/Web3Core/EthereumABI/ABIDecoding.swift

@@ -188,12 +188,12 @@ extension ABIDecoder {
     fileprivate static func followTheData(type: ABI.Element.ParameterType, data: Data, pointer: UInt64 = 0) -> (elementEncoding: Data?, nextElementPointer: UInt64?) {
         if type.isStatic {
             guard data.count >= pointer + type.memoryUsage else {return (nil, nil)}
-            let elementItself = data[pointer ..< pointer + type.memoryUsage]
+            let elementItself = data[data.indices.startIndex + Int(pointer) ..< data.indices.startIndex + Int(pointer + type.memoryUsage)]
             let nextElement = pointer + type.memoryUsage
             return (Data(elementItself), nextElement)
         } else {
             guard data.count >= pointer + type.memoryUsage else {return (nil, nil)}
-            let dataSlice = data[pointer ..< pointer + type.memoryUsage]
+            let dataSlice = data[data.indices.startIndex + Int(pointer) ..< data.indices.startIndex + Int(pointer + type.memoryUsage)]
             let bn = BigUInt(dataSlice)
             if bn > UInt64.max || bn >= data.count {
                 // there are ERC20 contracts that use bytes32 instead of string. Let's be optimistic and return some data

Sources/Web3Core/EthereumABI/ABIElements.swift

@@ -397,9 +397,9 @@ extension ABI.Element.Function {
         /// 4) `messageLength` is used to determine where message bytes end to decode string correctly.
         /// 5) The rest of the `data` must be 0 bytes or empty.
         if data.bytes.count >= 100,
-           Data(data[0..<4]) == Data.fromHex("08C379A0"),
-           BigInt(data[4..<36]) == 32,
-           let messageLength = Int(Data(data[36..<68]).toHexString(), radix: 16),
+           Data(data[data.indices.startIndex ..< data.indices.startIndex + 4]) == Data.fromHex("08C379A0"),
+           BigInt(data[data.indices.startIndex + 4 ..< data.indices.startIndex + 36]) == 32,
+           let messageLength = Int(Data(data[data.indices.startIndex + 36 ..< data.indices.startIndex + 68]).toHexString(), radix: 16),
            let message = String(bytes: data.bytes[68..<(68+messageLength)], encoding: .utf8),
            (68+messageLength == data.count || data.bytes[68+messageLength..<data.count].reduce(0) { $0 + $1 } == 0) {
             return ["_success": false,
@@ -410,11 +410,11 @@ extension ABI.Element.Function {
 
         if data.count >= 4,
            let errors = errors,
-           let customError = errors[data[0..<4].toHexString().stripHexPrefix()] {
+           let customError = errors[data[data.indices.startIndex + 0 ..< data.indices.startIndex + 4].toHexString().stripHexPrefix()] {
             var errorResponse: [String: Any] = ["_success": false, "_abortedByRevertOrRequire": true, "_error": customError.errorDeclaration]
 
             if (data.count > 32 && !customError.inputs.isEmpty),
-               let decodedInputs = ABIDecoder.decode(types: customError.inputs, data: Data(data[4..<data.count])) {
+               let decodedInputs = ABIDecoder.decode(types: customError.inputs, data: Data(data[data.indices.startIndex + 4 ..< data.indices.startIndex + data.count])) {
                 for idx in decodedInputs.indices {
                     errorResponse["\(idx)"] = decodedInputs[idx]
                     if !customError.inputs[idx].name.isEmpty {