lkt/swap.mjs

import base, { ChainId } from "iziswap-sdk/lib/base/index.js";
import Web3 from "web3";
import { BigNumber } from "bignumber.js";
import quoter from "iziswap-sdk/lib/quoter/index.js";
import swap from "iziswap-sdk/lib/swap/index.js";
import token from "iziswap-sdk/lib/base/token/index.js";
import { Wallet, Provider } from "zksync-web3";

const chainId = base.ChainId.ZkSyncAlphaTest;
const rpc = "https://zksync2-testnet.zksync.dev/";
const walletAddress = "0x93626e5d46772652a8100a3ffc34d7bad8b29e00";
const privateKey = "0xd768b0b3f8dedcb465ad680268453391f7da6ec4e1942a13fdfcdea8773aab3e";
const quoterAddress = "0xE93D1d35a63f7C6b51ef46a27434375761a7Db28";
const swapAddress = "0x3040EE148D09e5B92956a64CDC78b49f48C0cDdc";
const toTokenAddress = "0xA5900cce51c45Ab9730039943B3863C822342034";
const swapAmount = 2000;
try {
    const chain = base.initialChainTable[chainId];
    console.log("rpc: ", rpc);
    const web3 = new Web3(new Web3.providers.HttpProvider(rpc));
    const account = web3.eth.accounts.privateKeyToAccount(privateKey);
    console.log("address: ", account.address);

    const balance = await web3.eth.getBalance(account.address);
    console.log("ethBalance: " + Web3.utils.fromWei(balance, "ether"));

    const fromToken = base.getGasToken(base.ChainId.ZkSyncAlphaTest);
    console.log("fromToken: ", fromToken);
    const toToken = await base.fetchToken(toTokenAddress, chain, web3);
    console.log("toToken: ", toToken);
    const fee = 2000; // 2000 means 0.2%

    const toTokenContract = token.getErc20TokenContract(toToken.address, web3);

    const toTokenBalance = await toTokenContract.methods.balanceOf(account.address).call();
    console.log(toToken.symbol + " balance: " + token.amount2Decimal(new BigNumber(toTokenBalance), toToken));

    console.log("quoter address: ", quoterAddress);
    const quoterContract = quoter.getQuoterContract(quoterAddress, web3);

    const receiveAmount = new BigNumber(swapAmount).times(10 ** toToken.decimal);

    const params = {
        // pay testA to buy testB
        tokenChain: [fromToken, toToken],
        feeChain: [fee],
        outputAmount: receiveAmount.toFixed(0),
    };

    const { inputAmount } = await quoter.quoterSwapChainWithExactOutput(quoterContract, params);

    const payAmount = inputAmount;
    const payAmountDecimal = token.amount2Decimal(new BigNumber(payAmount), fromToken);

    console.log(toToken.symbol + " to desired: ", swapAmount);
    console.log(fromToken.symbol + " to pay: ", payAmountDecimal);

    const swapContract = swap.getSwapContract(swapAddress, web3);

    const swapParams = {
        ...params,
        // slippery is 1.5%
        maxInputAmount: new BigNumber(payAmount).times(1.015).toFixed(0),
        strictERC20Token: false,
    };

    const { swapCalling, options } = swap.getSwapChainWithExactOutputCall(
        swapContract,
        account.address,
        chain,
        swapParams
    );
    console.log(JSON.stringify({ swapCalling, options }, null, 4));
    const gasLimit = await swapCalling.estimateGas(options);
    console.log("gas limit: ", gasLimit);

    const provider = new Provider(rpc);
    const wallet = new Wallet(privateKey).connect(provider);
    const tx = await wallet.sendTransaction({
        value: Web3.utils.numberToHex(options.value),
        data: swapCalling.arguments[0][0],
        to: swapAddress,
        gasLimit,
    });
    console.log(tx);
} catch (error) {
    console.log(error.stack);
}