I’m trying to execute a swap using Uniswap V2 SDK in a Node.js environment.
However, when I run the code below, I receive the following error:
“Warning! Error encountered during contract execution [execution reverted]”
async function createPair() {
const pairAddress = Pair.getAddress(TOKEN, WETH9[TOKEN.chainId]);
const pairContract = new ethers.Contract(pairAddress, UniswapV2PoolAbi, provider);
const reserves = await pairContract['getReserves']();
const [reserve0, reserve1] = reserves;
const reserve0Parsed = BigInt(reserve0.toString()).toString();
const reserve1Parsed = BigInt(reserve1.toString()).toString();
const tokens = [TOKEN, WETH9[TOKEN.chainId]];
const [token0, token1] = tokens[0].sortsBefore(tokens[1]) ? tokens : [tokens[1], tokens[0]];
const pair = new Pair(
CurrencyAmount.fromRawAmount(token0, reserve0Parsed),
CurrencyAmount.fromRawAmount(token1, reserve1Parsed)
);
return pair;
}
async function swap() {
const amountIn = ethers.parseEther('0.00001').toString();
const slippageTolerance = new Percent('50', '10000');
const to = WALLET_ADDRESS;
const signer = new ethers.Wallet(WALLET_SECRET);
const account = signer.connect(provider);
const command = '0x08';
const deadline = 2 * 10 ** 10;
const fromEoa = true;
const uniswap = new ethers.Contract(
swapRouterAddress,
[
'function execute(bytes calldata commands, bytes[] calldata inputs, uint256 deadline) external payable returns (bytes[] memory outputs)',
],
account
);
const pair = await createPair();
const route = new Route([pair], WETH9[TOKEN.chainId], TOKEN);
const trade = new Trade(
route,
CurrencyAmount.fromRawAmount(WETH9[TOKEN.chainId], amountIn),
TradeType.EXACT_INPUT
);
const amountOutMin = trade.minimumAmountOut(slippageTolerance).toExact();
const amoutOut = ethers.parseEther(amountOutMin);
const pathData = ethers.solidityPacked(
['address', 'address'],
[WETH9[ChainId.BASE].address, TOKEN.address]
);
const v2Calldata = ethers.AbiCoder.defaultAbiCoder().encode(
['address', 'uint256', 'uint256', 'bytes', 'bool'],
[to, amountIn, amoutOut, pathData, fromEoa]
);
const tx = await uniswap.execute(command, [v2Calldata], deadline, {
value: amountIn,
gasPrice: ethers.parseUnits('0.15', 'gwei'),
gasLimit: 100000,
chainId: ChainId.BASE,
from: WALLET_ADDRESS,
});
console.log(`Transaction hash: ${tx.hash}`);
const receipt = await tx.wait();
console.log(`Transaction was mined in block ${receipt.blockNumber}`);
}
*/
Here’s a brief overview of what the code does:
- Imports necessary Uniswap V2 SDK components and ethers.js.
- Sets up provider with a QuickNode HTTP endpoint.
- Defines wallet address and secret.
- Creates a swapRouterAddress and a TOKEN.
- Defines a swap function that executes a swap using Uniswap V2.
- Inside the swap function:
- a. Sets up amountIn, slippage tolerance, recipient address, and signer.
- b. Creates a Uniswap contract instance.
- c. Calls createPair() to create a Uniswap pair.
- d. Calculates trade details and encodes calldata.
- e. Executes the swap with Uniswap’s execute() function.
I suspect the issue might be related to how I’m encoding the data or setting up
the transaction. Can someone help me understand why I’m getting this error
and how I can resolve it?
Also check some of my transactions:
https://basescan.org/tx/0x5a4ccdf8476eac2b41e00927cae6cb5817cff4acfb1c4746244ebd3d22784e9e
Thanks!
![https://i.stack.imgur.com/B3pG0.png]](https://i.stack.imgur.com/B3pG0.png%5D){kind=link}
