Failed to fetch gas estimate when trying to test contract method

[Gabets]

Hi all!
I'm tried to create simple iOS app and test contract on Kovan network and when I send transaction I get error:
processingError(desc: "Failed to fetch gas estimate")
My code:

main function:

private func addLiquidity() {        
        let token0: web3swift.EthereumAddress = EthereumAddress("0xd0a1e359811322d97991e03f863a0c30c2cf029c")! //  (WETH)
        let token1: web3swift.EthereumAddress = EthereumAddress("0x1484a6020a0f08400f6f56715016d2c80e26cdc1")! // (USDT)
        let ethAddress: web3swift.EthereumAddress = EthereumAddress("0xA394bE3499bece634fcBF4d89F2DFe9dABD72B54")! // wallet

        let amount0 = Web3.Utils.parseToBigUInt("0.5", units: .eth) ?? 0
        let amount1 = Web3.Utils.parseToBigUInt("1400.0", units: .eth) ?? 0
        
        let timeInterval = Date().timeIntervalSince1970
        let deadline = Int(timeInterval) + 300 
        
        var params = [Any]()
        params.append(token0)
        params.append(token1)
        params.append(ethAddress)
        params.append(amount0)
        params.append(amount1)
        params.append(BigUInt(0))
        params.append(BigUInt(0))
        params.append(BigUInt(deadline))
        
        let parameters = [params as AnyObject]        
        let contract = getContract()
        
        var options = TransactionOptions.defaultOptions
        options.value = amount0
        options.from = ethAddress
        options.gasPrice = .automatic
        options.gasLimit = .automatic
        
        let method: String = "addLiquidity"
        let tx: WriteTransaction? = contract.write(
            method,
            parameters: parameters as [AnyObject],
            extraData: Data(),
            transactionOptions: options)
        
        guard let transaction = tx else {
            print(" LOG transaction is nil")
            return
        }

        do {
            let result = try transaction.send(password: "") //yes, empty password string :) with transactionOptions: options got same error
            print(" LOG output \n", result.transaction.description as Any)
        } catch {
            print(error) // got processingError(desc: "Failed to fetch gas estimate")
        }
    }

getContract function:

private func getContract() -> web3.web3contract {        
        let contractABI: String = """
        [{"inputs":[{"internalType":"address","name":"router_","type":"address"},{"internalType":"address","name":"factory_","type":"address"},{"internalType":"address","name":"pocket_","type":"address"},{"internalType":"address","name":"WETH9_","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"WETH9","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"_owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"token0","type":"address"},{"internalType":"address","name":"token1","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount0Desired","type":"uint256"},{"internalType":"uint256","name":"amount1Desired","type":"uint256"},{"internalType":"uint256","name":"amount0Min","type":"uint256"},{"internalType":"uint256","name":"amount1Min","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"internalType":"struct IPocketSwapLiquidityRouter.AddLiquidityParams","name":"params","type":"tuple"}],"name":"addLiquidity","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"factory","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"},{"internalType":"address[]","name":"path","type":"address[]"}],"name":"getAmountsIn","outputs":[{"internalType":"uint256[]","name":"","type":"uint256[]"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"address[]","name":"path","type":"address[]"}],"name":"getAmountsOut","outputs":[{"internalType":"uint256[]","name":"","type":"uint256[]"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"pocket","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"tokenA","type":"address"},{"internalType":"address","name":"tokenB","type":"address"},{"internalType":"uint256","name":"liquidity","type":"uint256"},{"internalType":"uint256","name":"amountAMin","type":"uint256"},{"internalType":"uint256","name":"amountBMin","type":"uint256"},{"internalType":"address","name":"rewards","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"internalType":"struct IPocketSwapLiquidityRouter.RemoveLiquidityParams","name":"params","type":"tuple"}],"name":"removeLiquidity","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"router","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"tokenIn","type":"address"},{"internalType":"address","name":"tokenOut","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"uint256","name":"amountOutMinimum","type":"uint256"}],"internalType":"struct IPocketSwapRouter.SwapParams","name":"params","type":"tuple"}],"name":"swap","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"}],"name":"sweepToken","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"}],"name":"unwrapWETH9","outputs":[],"stateMutability":"payable","type":"function"}]
        """

        let web3 = infuraKovanWeb3()        
        let contractAddress: web3swift.EthereumAddress = EthereumAddress("0x812809F2BeAE43ba3fC9719fAb171E2A20F9Fb50")!
        let contract = web3.contract(contractABI, at: contractAddress)

        return contract!
    }

and infuraKovanWeb3 function:

private func infuraKovanWeb3(accessToken: String? = nil) -> web3 {
        let infura = InfuraProvider(Networks.Kovan, accessToken: accessToken)!
        return web3(provider: infura)
    }

could somebody help me with this issue?

можно отвечать и на русском)

[Gabets]

As I think, main problem - correcttly pass parameters in to the contract method. In this exaple

inputs is an object that contains several parameters

My question is: "How do I pass the oblect correctly"?

I tryed pass as object, as dictionary, as tuple, as array of tuples but all time I got problem in this place:

Object values are treated as one value, not as array that can be encoded.

For example, contract method input argument is object named params and below his representation:

struct InputParams {
    address token; // Address of the token
    uint256 amountDesired; // Amount of the token
    uint256 deadline; // Reverts in case of transaction confirmed too late 
}

How I can pass it to contract method? Any ideas?

[Gabets]

little update:
if I try

let result1 = try transaction.call()

I get nodeError(desc: "VM execution error.")

if I try

let estimate = try transaction.estimateGas(transactionOptions: options)

I got nodeError(desc: "The execution failed due to an exception.")

still need help :(

[Iysbaera]

@Gabets Hey, please check #324, it might be the solution for your issue,

[Gabets]

@Iysbaera Hello, I will look, thank you.

[AlleniCode]

@Gabets Hello，how to make a swap transaction with Uniswap's contracts?

Uniswap

1、UniswapV2Router02

https://etherscan.io/address/0x7a250d5630b4cf539739df2c5dacb4c659f2488d#code

https://unpkg.com/@uniswap/v2-periphery@1.1.0-beta.0/build/IUniswapV2Router02.json

2、Vyper_contract

https://etherscan.io/address/0xc0a47dfe034b400b47bdad5fecda2621de6c4d95#code

3、UniswapV2Factory

https://etherscan.io/address/0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f#code

https://unpkg.com/@uniswap/v2-core@1.0.0/build/IUniswapV2Factory.json

[Gabets]

@AlleniCode Hello!
Thank you , but not the same I think. For example https://etherscan.io/address/0x7a250d5630b4cf539739df2c5dacb4c659f2488d#writeContract
look at addLiquidity method parameters and same method the contract I work with: https://kovan.etherscan.io/address/0x812809F2BeAE43ba3fC9719fAb171E2A20F9Fb50#writeContract
problem was - how to pass object, I hadn't problem with the simple values

[anonymouz4]

Hi, removing the value fixed it for me, see #147