Uniswap SDK implementation

index.js

#!/usr/bin/env node
const ethers = require('ethers');
const IWETH = require('@uniswap/v2-periphery/build/IWETH.json');
const uniswapsdk = require('simple-uniswap-sdk');

class Uniswap {

	provider;
	wallet;

	constructor(rpcUrl, privateKey) {
		this.provider = new ethers.providers.JsonRpcProvider(rpcUrl)
		this.wallet = new ethers.Wallet(privateKey, this.provider);
	}

	async wrapNativeToken(toTokenContractAddress, amountToSwap) {
		const wrapEthContract = new ethers.Contract(
			toTokenContractAddress,
			IWETH['abi'],
			this.wallet
		);

		const tx = await wrapEthContract.deposit({value: ethers.utils.parseUnits(amountToSwap, 18)});

		const approveReceipt = await tx.wait();

		if (approveReceipt.status === 0) throw new Error(`Failed to swap ETH to WETH`);

		console.log(`Succesfully swap ETH to WETH!`);
		console.log(`Transaction Hash: ${approveReceipt.hash}`);
		console.log(JSON.stringify(approveReceipt));
	}
	
	async unwrapNativeToken(fromTokenContractAddress, amountToSwap) {
		const wrapEthContract = new ethers.Contract(
			fromTokenContractAddress,
			IWETH['abi'],
			this.wallet
		);

		const tx = await wrapEthContract.withdraw(ethers.utils.parseUnits(amountToSwap, 18));

		const approveReceipt = await tx.wait();

		if (approveReceipt.status === 0) throw new Error(`Failed to swap WETH to ETH`);
		
		console.log(`Succesfully swap WETH to ETH!`);
		console.log(`Transaction Hash: ${approveReceipt.hash}`);
		console.log(JSON.stringify(approveReceipt));
	}

	async swapToken(fromTokenContractAddress, toTokenContractAddress, chainId, amountToSwap) {
		const uniswapPair = new uniswapsdk.UniswapPair({
			fromTokenContractAddress,
			toTokenContractAddress,
			ethereumAddress: this.wallet.address,
			ethereumProvider: this.provider,
			chainId,
			settings: new uniswapsdk.UniswapPairSettings({
				slippage: 0.0005,
				deadlineMinutes: 20,
			}),
		});

		const uniswapPairFactory = await uniswapPair.createFactory();

		const trade = await uniswapPairFactory.trade(amountToSwap);

		if (!trade.fromBalance.hasEnough) {
			throw new Error('You do not have enough from balance to execute this swap');
		}
		
		// Why we need two transactions: https://github.com/joshstevens19/simple-uniswap-sdk#ethers-example
		if (trade.approvalTransaction) {
			const approved = await wallet.sendTransaction(trade.approvalTransaction);
			await approved.wait();
		}

		const tradeTransaction = await wallet.sendTransaction(trade.transaction);
		await tradeTransaction.wait();

		trade.destroy();

		console.log(`Succesfully swap ${fromTokenContractAddress} to ${toTokenContractAddress}!`);
		console.log(`Transaction Hash: ${tradeTransaction.hash}`);
		console.log(JSON.stringify(tradeTransaction));
	}
}

const privateKey = "<PRIVATE_KEY>";
const rpcUrl = "<RPC_URL>";
const uniswap = new Uniswap(rpcUrl, privateKey);

/** WETH address
 *[Mainnet]: 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
 *[Ropsten Testnet]: 0xc778417E063141139Fce010982780140Aa0cD5Ab
 *[Rinkeby Testnet]: 0xc778417E063141139Fce010982780140Aa0cD5Ab
 *[Kovan Testnet]: 0xd0A1E359811322d97991E03f863a0C30C2cF029C
*/

// Swapping ETH to WETH
uniswap.wrapNativeToken("0xc778417E063141139Fce010982780140Aa0cD5Ab", "0.01");

// Swapping WETH to ETH
uniswap.unwrapNativeToken("0xc778417E063141139Fce010982780140Aa0cD5Ab", "0.01");

/** Swapping WETH to DAI on Rinkeby (ERC20-ERC20)
 * WETH Rinkeby - 0xc778417E063141139Fce010982780140Aa0cD5Ab
 * DAI Rinkeby - 0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735
 * Rinkby ChainId - 4
*/
uniswap.swapToken(
	"0xc778417E063141139Fce010982780140Aa0cD5Ab",
	"0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735",
	4,
	"0.01"
);

/** Swapping Native ETH to DAI on Rinkeby (ETH-ERC20)
 * ETH Rinkeby - 0xc778417E063141139Fce010982780140Aa0cD5Ab_ETH
 * DAI Rinkeby - 0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735
 * Rinkby ChainId - 4
*/
uniswap.swapToken(
	"0xc778417E063141139Fce010982780140Aa0cD5Ab_ETH",
	"0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735",
	4,
	"0.01"
);

package.json

{
  "name": "uniswap-example",
  "version": "1.0.0",
  "bin": "./index.js",
  "scripts": {
    "start": "node index.js"
  },
  "type": "module",
  "dependencies": {
    "@uniswap/v2-periphery": "^1.1.0-beta.0",
    "ethers": "^5.6.8",
    "simple-uniswap-sdk": "^3.7.0"
  }
}

swap.js

async swapToken(fromTokenContractAddress, toTokenContractAddress, chainId, amountToSwap) {
	const uniswapPair = new uniswapsdk.UniswapPair({
		fromTokenContractAddress,
		toTokenContractAddress,
		ethereumAddress: this.wallet.address,
		ethereumProvider: this.provider,
		chainId,
		settings: new uniswapsdk.UniswapPairSettings({
			slippage: 0.0005,
			deadlineMinutes: 20,
		}),
	});

	const uniswapPairFactory = await uniswapPair.createFactory();

	const trade = await uniswapPairFactory.trade(amountToSwap);

	if (!trade.fromBalance.hasEnough) {
		throw new Error('You do not have enough from balance to execute this swap');
	}

	// Why we need two transactions: https://github.com/joshstevens19/simple-uniswap-sdk#ethers-example
	if (trade.approvalTransaction) {
		const approved = await wallet.sendTransaction(trade.approvalTransaction);
		await approved.wait();
	}

	const tradeTransaction = await wallet.sendTransaction(trade.transaction);
	await tradeTransaction.wait();

	trade.destroy();

	console.log(`Succesfully swap ${fromTokenContractAddress} to ${toTokenContractAddress}!`);
	console.log(`Transaction Hash: ${tradeTransaction.hash}`);
	console.log(JSON.stringify(tradeTransaction));
}

uniswap-class.js

const ethers = require('ethers');
const IWETH = require('@uniswap/v2-periphery/build/IWETH.json');
const uniswapsdk = require('simple-uniswap-sdk');

class Uniswap {

	provider;
	wallet;

	constructor(rpcUrl, privateKey) {
		this.provider = new ethers.providers.JsonRpcProvider(rpcUrl)
		this.wallet = new ethers.Wallet(privateKey, this.provider);
	}
}

const privateKey = "<PRIVATE_KEY>";
const rpcUrl = "<RPC_URL>";
const uniswap = new Uniswap(rpcUrl, privateKey);

unwrap.js

async unwrapNativeToken(fromTokenContractAddress, amountToSwap) {
	const wrapEthContract = new ethers.Contract(
		fromTokenContractAddress,
		IWETH['abi'],
		this.wallet
	);

	const tx = await wrapEthContract.withdraw(ethers.utils.parseUnits(amountToSwap, 18));

	const approveReceipt = await tx.wait();

	if (approveReceipt.status === 0) throw new Error(`Failed to swap WETH to ETH`);

	console.log(`Succesfully swap WETH to ETH!`);
	console.log(`Transaction Hash: ${approveReceipt.hash}`);
	console.log(JSON.stringify(approveReceipt));
}

wrap.js

async wrapNativeToken(toTokenContractAddress, amountToSwap) {
	const wrapEthContract = new ethers.Contract(
		toTokenContractAddress,
		IWETH['abi'],
		this.wallet
	);

	const tx = await wrapEthContract.deposit({value: ethers.utils.parseUnits(amountToSwap, 18)});

	const approveReceipt = await tx.wait();

	if (approveReceipt.status === 0) throw new Error(`Failed to swap ETH to WETH`);

	console.log(`Succesfully swap ETH to WETH!`);
	console.log(`Transaction Hash: ${approveReceipt.hash}`);
	console.log(JSON.stringify(approveReceipt));
}