Web3.js Error Handling: Converting BigInts in Event Listeners
When working with Web3.js, you often encounter situations where you need to handle events and responses in a specific way. I recently encountered an error while trying to convert a BigInt object to an event listener response using the library’s built-in functions.
Problem: Error type: Don’t know how to split a BigInt array
In my case, the problem was that Web3.js couldn’t serialize and deserialize BigInt objects. This can happen when you try to pass or receive a lot of data between different parts of your application. However, some libraries (including Web3.js) don’t support consistency for BigInt objects.
Solution: Custom Conversion Function
To solve this problem, we need to create a custom function that converts BigInt objects to strings before sending them as an event listener response. We can use the “BigInt.toString()” method for this purpose.
Here is an example of how you can implement this:
const web3 = require('web3');
const Web3 = require('@web3/web3');
// Replace "YOUR-WALLET-CRET" with the actual wallet secret
const networkID = 1; // Ethereum network
const web3Provider = new web3.providers.HttpProvider('
const provider = new web3.providers.HTTPProvider(networkID, web3provider);
web3.eth.on('block', (block) => {
const bigIntBlockNumber = BigInt(block.number);
const transactionHash = BigInt(block.hash);
// Converts BigINT to string
const bigIntTransactionHash = bigIntTransactionHash.toString();
console.log(Event listener response: ${bigIntTransactionHash});
});
In this example, we create a custom `toString() function that converts BigInt objects to strings. We then pass this function as the second argument to `web3.eth.on(‘block’, …)’.
Benefit: no more type errors
Using a custom conversion function, we can successfully send and receive events from Web3.js even with a large amount of data (in this case, BigInt objects). The rest of the code remains the same.
Please note that you will need to replace “YOUR-WALLET-SECRET”, “networkId”, and “bigIntTransactionHash” with actual values specific to your project. Additionally, make sure your wallet provider is properly configured and active on your Ethereum network.