lkt/approve.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 liquidityManager from "iziswap-sdk/lib/liquidityManager/index.js";
import pool from "iziswap-sdk/lib/pool/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 liquidityManagerAddress = "0x25727b360604E1e6B440c3B25aF368F54fc580B6";
const tokenAAddress = "0x00";
const tokenBAddress = "0xA5900cce51c45Ab9730039943B3863C822342034";

const provider = new Provider(rpc);
const wallet = new Wallet(privateKey).connect(provider);
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 liquidityManagerContract = liquidityManager.getLiquidityManagerContract(liquidityManagerAddress, web3);
console.log("liquidity manager address: ", liquidityManagerAddress);

const tokenA = base.getGasToken(chainId);
console.log("tokenA: ", tokenA);
const tokenB = await token.fetchToken(tokenBAddress, chain, web3);
console.log("tokenB: ", tokenB);

async function approve(tokenAddress) {
    const erc20ABI = [
        {
            inputs: [
                {
                    internalType: "address",
                    name: "spender",
                    type: "address",
                },
                {
                    internalType: "uint256",
                    name: "amount",
                    type: "uint256",
                },
            ],
            name: "approve",
            outputs: [
                {
                    internalType: "bool",
                    name: "",
                    type: "bool",
                },
            ],
            stateMutability: "nonpayable",
            type: "function",
        },
    ];
    const tokenAContract = new web3.eth.Contract(erc20ABI, tokenAddress);
    // you could approve a very large amount (much more greater than amount to transfer),
    // and don't worry about that because liquidityManager only transfer your token to pool with amount you specified and your token is safe
    // then you do not need to approve next time for this user's address
    const approveCalling = tokenAContract.methods.approve(
        liquidityManagerAddress,
        "0xffffffffffffffffffffffffffffffff"
    );
    // estimate gas
    let gasLimit = await approveCalling.estimateGas({ from: account.address });
    console.log("approve gas limit: ", gasLimit);
    // then send transaction to approve
    // you could simply use followiing line if you use metamask in your frontend code
    // otherwise, you should use the function "web3.eth.accounts.signTransaction"
    // notice that, sending transaction for approve may fail if you have approved the token to liquidityManager before
    // if you want to enlarge approve amount, you should refer to interface of erc20 token
    const tx0 = await wallet.sendTransaction({
        from: account.address,
        to: tokenAddress,
        data: approveCalling.encodeABI(),
        gasLimit,
    });
    console.log("approve tx: ", JSON.stringify(tx0, null, 4));
}

await approve(tokenA.address);