Ethereum: Ethers.js: getLogs returning empty results despite existing transactions

Ethereum Ethers.js: Getting Empty Results Despite Existing Transactions

When building decentralized applications, tracking transactions is crucial to auditing and ensuring the integrity of your smart contracts. A common issue when working with the Ethereum blockchain is getting empty results from getLogs despite existing transactions.

In this article, we will explore why you might be seeing this behavior and how to troubleshoot and resolve it using Ethers.js.

The Problem:

getLogs returns an array of logs that contain information about transactions on the Ethereum network. However, if there are no new or updated transactions for a specific address within a certain time period (also known as the “last block” or “block number”), getLogs will return an empty array.

Why You Might Be Seeing Empty Results

There could be several reasons why you are seeing empty results from getLogs. Here are some possible causes:

• No new transactions: If there are no new USDT transfers to specific wallet addresses within a certain period of time, getLogs will not return any logs.

• Old block number

  : If the last block number is older than the block number you are interested in (e.g. 100 blocks ago), getLogs may not return any results because there are no new transactions to fetch from that block.

• Network congestion or slow transaction processing: On a high-traffic network, it is possible that some transactions are delayed or dropped, resulting in empty logs.

Troubleshooting steps

To resolve this issue, try the following steps:

• Check for existing transactions: Verify that there are indeed USDT transfers to specific wallet addresses by checking their balances and transaction history using other APIs or tools (e.g. MetaMask).

• Set a reasonable limit on the number of blocks: Increase your blockNumber parameter when calling getLogs. This will force Ethers.js to fetch logs from the specified number of blocks onwards.

• Use pagination: If there are many transactions within a specific time period, consider using pagination to fetch results in blocks. This can help you process larger data sets more efficiently.

Sample Code

Here is a sample code snippet that demonstrates how to use getLogs with pagination:

import * as ethers from 'ethers';
const walletAddress = '0x...'; // Replace with your desired wallet address
const blockNumber = 100; // Set a reasonable limit for fetching logs
async function getLogs() {
const provider = new ethers.providers.Web3Provider(window.ethereum);
try {
const logs = await provider.getLogs({
address: walletAddress,
blockNumber: blockNumber,
fromBlock: blockNumber,
toBlock: Infinity, // Fetch all transactions in the current block
});
return logs;
} catch (error) {
console.error(error);
return [];
}
}
// Call getLogs with pagination
getLogs().then(logs => console.log(logs));

By following these steps and using pagination, you should be able to resolve the issue of getting empty results from getLogs despite existing transactions.