Optional blocknumber for estimate_gas

Author: Vadym Pavlov

Sources/Web3Core/EthereumNetwork/Request/APIRequest+ComputedProperties.swift

@@ -22,7 +22,7 @@ extension APIRequest {
             return [RequestParameter]()
 
         case .estimateGas(let transactionParameters, let blockNumber):
-            return [.transaction(transactionParameters), .string(blockNumber.description)]
+            return [.transaction(transactionParameters), blockNumber.map { .string($0.description) }].compactMap { $0 }
 
         case let .sendRawTransaction(hash):
             return [.string(hash)]

Sources/Web3Core/EthereumNetwork/Request/APIRequest.swift

@@ -96,7 +96,7 @@ public enum APIRequest {
     /// - Parameters:
     ///     - TransactionParameters: parameters of planned transaction
     ///     - BlockNumber: block where it should be evaluated
-    case estimateGas(CodableTransaction, BlockNumber)
+    case estimateGas(CodableTransaction, BlockNumber?)
 
     /// Send raw transaction
     /// - Parameters:

Sources/web3swift/EthereumAPICalls/Ethereum/IEth+Defaults.swift

@@ -20,7 +20,7 @@ public extension IEth {
         try await estimateGas(for: transaction, onBlock: .latest)
     }
 
-    func estimateGas(for transaction: CodableTransaction, onBlock: BlockNumber) async throws -> BigUInt {
+    func estimateGas(for transaction: CodableTransaction, onBlock: BlockNumber?) async throws -> BigUInt {
         let request = APIRequest.estimateGas(transaction, onBlock)
         return try await APIRequest.sendRequest(with: provider, for: request).result
     }

Sources/web3swift/EthereumAPICalls/Ethereum/IEth.swift

@@ -13,7 +13,7 @@ public protocol IEth {
     func send(_ transaction: CodableTransaction) async throws -> TransactionSendingResult
     func send(raw data: Data) async throws -> TransactionSendingResult
 
-    func estimateGas(for transaction: CodableTransaction, onBlock: BlockNumber) async throws -> BigUInt
+    func estimateGas(for transaction: CodableTransaction, onBlock: BlockNumber?) async throws -> BigUInt
     func feeHistory(blockCount: BigUInt, block: BlockNumber, percentiles: [Double]) async throws -> Oracle.FeeHistory
     func ownedAccounts() async throws -> [EthereumAddress]
     func getBalance(for address: EthereumAddress, onBlock: BlockNumber) async throws -> BigUInt