Uniswap USDC=> ETH交换

Question

试图将USDC交换给ETH vith Uniswap和Ether，但一直都有错误。

async function swapUsdcToEth(amount, walledAddress) {
  const usdc = await Fetcher.fetchTokenData(chainId, '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48');
  const eth = await Fetcher.fetchTokenData(chainId, '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2');
  const pair = await Fetcher.fetchPairData(usdc, eth);
  const route = new Route([pair], usdc);
  const amountIn = new TokenAmount(usdc, amount);
  const trade = new Trade(route, amountIn, TradeType.EXACT_INPUT);
  const slippageTolerance = new Percent('50', '10000');
  const value = ethers.BigNumber.from(trade.inputAmount.raw.toString()).toHexString();
  const amountOutMin = ethers.BigNumber.from(trade.minimumAmountOut(slippageTolerance).raw.toString()).toHexString();
  const deadline = Math.floor(Date.now() / 1000) + 60 * 20;
  const uniswapRouterV2Address = '0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D';
  const provider = new ethers.providers.JsonRpcProvider('https://mainnet.infura.io/v3/b9fkdmkdkdv4937b52ea9637cf1d1bd');
  const signer = new ethers.Wallet(walledAddress, provider);
  const uniswap = new ethers.Contract(
    uniswapRouterV2Address,
    ['function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts)'],
    signer
  );
  try {
    const tx = await uniswap.swapExactTokensForETH(value, amountOutMin, [walledAddress], walledAddress, deadline);
    const receipt = await tx.wait();
    console.log('transaction was mined in block', receipt.blockNumber);
  } catch (e) {
    console.log(e);
  }
}

接收错误：“错误:无法估计气体；交易可能失败或可能需要手动气体限制”。我做错什么了？

Answer 1

所以看起来可能有几件事。您是否已批准您的令牌由路由器使用？我也没有看到任何气体设置在那里

下面是我修改过的一个工作版本，以使其工作正常(这是在一个主干网分叉上测试的设置，但是它使用的是实时数据(因为AlphaRouter只用于主存数据，所以活动数据和分叉数据将随着时间的推移而变化，从而导致交易错误，因此在使用之前请重新设置分叉)

使主网只取出本地提供商，并将所有提供程序更改为主网络提供商。

谨慎使用，我不是完美的，什么都不保证:检查滑动和所有变量

这是一个令牌，作为一个令牌Exact_Input交换与魏斯存款1 ETH。若要使用ETH，可以在批准时删除Weth存款和令牌，并将BigNumber.from(typedValueParsed)用作事务的值，而不是0。

由于我不知道EtherJS井的煤气价格和煤气限值为100 gwei &300 K，应按目前的管网煤气价格和估计的煤气限额进行修改。

import { AlphaRouter } from '@uniswap/smart-order-router'
import { Token, CurrencyAmount } from '@uniswap/sdk-core'
import { JSBI, Percent } from "@uniswap/sdk";
import { ethers, BigNumber } from "ethers";


const V3_SWAP_ROUTER_ADDRESS = "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45";

const TokenInput = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2";

const TokenOutput = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";


const web3Provider = new ethers.providers.JsonRpcProvider("https://eth-mainnet.alchemyapi.io/v2/");
const web3 = new ethers.providers.JsonRpcProvider("http://127.0.0.1:8545/");

const privateKey = "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80";
const wallet = new ethers.Wallet(privateKey,web3);
const address = wallet.address;

import * as fs from 'fs';

let UniV3RouterAbi = fs.readFileSync('NewUniRouter.json');
const V3routerAbi = JSON.parse(UniV3RouterAbi);

let ERC20Abi = fs.readFileSync('ERC20.json');
const ERC20 = JSON.parse(ERC20Abi);

let WETHAbij = fs.readFileSync('WETHAbi.json');
const WETHAbi = JSON.parse(WETHAbij);

async function log(inpt){
    console.log(inpt);
    console.log("");
}

async function TokBal(tokens){
    var ERC20contract =  new ethers.Contract(tokens, ERC20, web3);
    var myERC20bal = await ERC20contract.balanceOf(wallet.address);
    return myERC20bal;
}

async function Deposit(amt){
    var WethC =  new ethers.Contract(TokenInput, WETHAbi, web3);
    var datac = await WethC.populateTransaction["deposit"]();
    var ncn = await wallet.getTransactionCount();

    const transaction = {
      data: datac.data,
      nonce: ncn,
      to: TokenInput,
      value: BigNumber.from(amt),
      from: wallet.address,
      gasPrice: '0x174876e800',
      gasLimit: '0x493e0',
    };

    const signedTx = await wallet.signTransaction(transaction);
    const txHash =  await web3.sendTransaction(signedTx);
    log(txHash.hash);
}

async function Approve(Toked, amt){
    var WethC =  new ethers.Contract(Toked, ERC20, web3);
    var datac = await WethC.populateTransaction["approve"](V3_SWAP_ROUTER_ADDRESS, amt);
    var ncn = await wallet.getTransactionCount();

    const transaction = {
      data: datac.data,
      nonce: ncn,
      to: Toked,
      value: BigNumber.from("0"),
      from: wallet.address,
      gasPrice: '0x174876e800',
      gasLimit: '0x493e0',
    };

    const signedTx = await wallet.signTransaction(transaction);
    const txHash =  await web3.sendTransaction(signedTx);
    log(txHash.hash);
    var appFor = await WethC.callStatic.allowance(wallet.address, V3_SWAP_ROUTER_ADDRESS);
    log("Approved : "+appFor.toString());
}


const router = new AlphaRouter({ chainId: 1, provider: web3Provider });
const WETH = new Token(
  router.chainId,
  '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  18,
  'WETH',
  'Wrapped Ether'
);

const USDC = new Token(
  router.chainId,
  '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  6,
  'USDC',
  'USD//C'
);

const typedValueParsed = '1000000000000000000';
const wethAmount = CurrencyAmount.fromRawAmount(WETH, JSBI.BigInt(typedValueParsed));

const IO = "Exact_Input"
const TradeType = IO == "Exact_Input" ? 0 : 1;


const route = await router.route(
  wethAmount,
  USDC,
  TradeType,
  {
    recipient: wallet.address,
    slippageTolerance: new Percent(5, 100),
    deadline: Math.floor(Date.now()/1000 +1800)
  }
);

var Ebal = await web3.getBalance(wallet.address);
log("Wallet Balance : "+Ebal.toString());

var tbal = await TokBal(TokenOutput);
log("Token Out Balance : "+tbal.toString());

await Deposit("1000000000000000000");
await Approve(TokenInput,"1000000000000000000");
var tbalW = await TokBal(TokenInput);
log("Token In Balance : "+tbalW.toString());

log(`Quote Exact In: ${route.quote.toFixed(wethAmount.currency === WETH ? USDC.decimals : WETH.decimals)}`);
log(`Gas Adjusted Quote In: ${route.quoteGasAdjusted.toFixed(wethAmount.currency === WETH ? USDC.decimals : WETH.decimals)}`);


var nc = await wallet.getTransactionCount();


const transaction = {
  data: route.methodParameters.calldata,
  nonce: nc,
  to: V3_SWAP_ROUTER_ADDRESS,
  value: BigNumber.from(0),
  from: wallet.address,
  gasPrice: BigNumber.from(route.gasPriceWei),
  gasLimit: BigNumber.from(route.estimatedGasUsed).add(BigNumber.from("50000")),
};


const signedTx = await wallet.signTransaction(transaction);


const PretxHash = ethers.utils.keccak256(signedTx);


const txHash =  await web3.sendTransaction(signedTx)
log(txHash.hash);

var Ebal = await web3.getBalance(wallet.address);
log("Wallet Balance : "+Ebal.toString());

var tbal = await TokBal(TokenOutput);
log("Token Out Balance : "+tbal.toString());

var tbalW = await TokBal(TokenInput);
log("Token In Balance : "+tbalW.toString());

要获得ETH，请使用它来代替输出令牌

outPutAddress === WETH9[chainId].address ? nativeOnChain(chainId) : outPutToken,