Error in Documentation Examples: "Failed to fetch gas estimate"

[jimmyneutront]

I'm running a very simple test that is almost entirely copied from the documentation examples here. I start a local Hardhat node, import 2 Ethereum accounts using the private keys of two pre-funded accounts set up by Hardhat, and then attempt to send 1 ETH from the first account to the second. Again, the code with which I am trying to do this is almost entirely copied and pasted from the documentation examples linked above. I have tried fetching web3swift both from the "master" branch and the "develop" branch; the error occurs either way.
Prerequisites:
Open an Xcode project that depends on web3swift, create a new unit test class and add web3swift as a testable import.
Steps to Reproduction:
Paste the following function into the newly created unit test class:

func testTransferEth() {

    //Restore Hardhat account #1
    let password_one = "web3swift"
    let key_one = "59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d" // Some private key
    let formattedKey_one = key_one.trimmingCharacters(in: .whitespacesAndNewlines)
    let dataKey_one = Data.fromHex(formattedKey_one)!
    let keystore_one = try! EthereumKeystoreV3(privateKey: dataKey_one, password: password_one)!
    let keyData_one = try! JSONEncoder().encode(keystore_one.keystoreParams)
    let address_one = keystore_one.addresses!.first!.address
   
    //Restore Hardhat account #2
    let password_two = "web3swift"
    let key_two = "5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a" // Some private key
    let formattedKey_two = key_two.trimmingCharacters(in: .whitespacesAndNewlines)
    let dataKey_two = Data.fromHex(formattedKey_two)!
    let keystore_two = try! EthereumKeystoreV3(privateKey: dataKey_two, password: password_two)!
    let keyData_two = try! JSONEncoder().encode(keystore_two.keystoreParams)
    let address_two = keystore_two.addresses!.first!.address
    
    //Establish connection to Hardhat node
    let endpoint = "http://192.168.1.12:8545"
    let web3 = web3(provider: Web3HttpProvider(URL(string: endpoint)!)!)
    let keystoreManager = KeystoreManager([keystore_one, keystore_two])
    web3.addKeystoreManager(keystoreManager)
    
    //Transfer 1 ETH from account #1 to account #2
    let value: String = "1.0" // In Ether
    let walletAddress = EthereumAddress(address_one)! // Your wallet address
    let toAddress = EthereumAddress(address_two)!
    let contract = web3.contract(Web3.Utils.coldWalletABI, at: toAddress, abiVersion: 2)!
    let amount = Web3.Utils.parseToBigUInt(value, units: .eth)
    var options = TransactionOptions.defaultOptions
    options.value = amount
    options.from = walletAddress
    options.gasPrice = .automatic
    options.gasLimit = .automatic
    let tx = contract.write(
        "fallback",
        parameters: [AnyObject](),
        extraData: Data(),
        transactionOptions: options)!
    let password = "web3swift"
    let result = try! tx.send(password: password)

}

Run the unit test.

Expected Result:
1 ETH is successfully transferred from the first account to the second account.

Actual Result:
The following error is thrown:

    iosAppTests/TestClass.swift:67: Fatal error: 'try!' expression unexpectedly raised an error: web3swift.Web3Error.processingError(desc: "Failed to fetch gas estimate")
    2021-12-08 00:32:34.572536-0500 iosApp[9023:569768] iosAppTests/TestClass.swift:67: Fatal error: 'try!' expression unexpectedly raised an error: web3swift.Web3Error.processingError(desc: "Failed to fetch gas estimate")

Any idea what is going wrong here?

Environment:
OS: macOS Monterey 12.0.1
Xcode: 13.1 (13A1030d)
web3swift: freshly installed from 'develop' branch

[jimmyneutront]

I was able to resolve the issue by replacing
options.gasPrice = .automatic
options.gasLimit = .automatic
with
options.gasPrice = .manual(BigUInt(875000000))
options.gasLimit = .manual(BigUInt(30000000))