1. Use Try-Catch Blocks

Wrap your asynchronous calls in try-catch blocks to catch errors effectively. This allows you to handle exceptions without crashing your application.

async function sendTransaction() {
    try {
        const txResponse = await wallet.sendTransaction(tx);
        console.log("Transaction sent! Hash:", txResponse.hash);
    } catch (error) {
        console.error("Error sending transaction:", error);
    }
}
    

2. Check for Specific Error Types

Ethers.js provides specific error types that can help you identify the nature of the error. Use these to provide more informative error messages.

import { ethers } from "ethers";

try {
    const balance = await provider.getBalance(address);
} catch (error) {
    if (error.code === ethers.errors.INVALID_ARGUMENT) {
        console.error("Invalid argument provided:", error.message);
    } else if (error.code === ethers.errors.NETWORK_ERROR) {
        console.error("Network error:", error.message);
    } else {
        console.error("An unexpected error occurred:", error);
    }
}
    

3. Validate Inputs Before API Calls

Always validate inputs before making API calls to prevent unnecessary errors. For example, check if an address is valid:

const address = "0xInvalidAddress";
if (!ethers.utils.isAddress(address)) {
    console.error("Invalid Ethereum address:", address);
} else {
    // Proceed with the API call
}
    

4. Use Event Listeners for Transaction Status

When sending transactions, use event listeners to monitor the transaction status. This can help you handle errors related to transaction failures:

const txResponse = await wallet.sendTransaction(tx);
txResponse.wait().then((receipt) => {
    console.log("Transaction mined in block:", receipt.blockNumber);
}).catch((error) => {
    console.error("Transaction failed:", error);
});
    

5. Implement Retry Logic

For transient errors, such as network issues, consider implementing retry logic. This can help improve the resilience of your application:

async function sendTransactionWithRetry(tx, retries = 3) {
    for (let i = 0; i < retries; i++) {
        try {
            const txResponse = await wallet.sendTransaction(tx);
            console.log("Transaction sent! Hash:", txResponse.hash);
            return;
        } catch (error) {
            console.error("Error sending transaction:", error);
            if (i === retries - 1) throw error; // Rethrow after final attempt
        }
    }
}
    

6. Log Errors for Monitoring

Implement logging for errors to monitor issues in production. This can help you identify patterns and improve your application:

function logError(error) {
    // Send error to a logging service or console
    console.error("Logged Error:", error);
}

// Usage
try {
    const balance = await provider.getBalance(address);
} catch (error) {
    logError(error);
}
    

7. User-Friendly Error Messages

Provide user-friendly error messages in your application. Avoid exposing raw error messages to users, as they may be confusing:

try {
    const txResponse = await wallet.sendTransaction(tx);
} catch (error) {
    alert("Transaction failed. Please try again later.");
    console.error("Detailed error:", error);
}
    

Conclusion

By following these best practices for error handling in Ethers.js, you can create a more robust and user-friendly application that effectively manages errors and provides meaningful feedback to users.