Understanding Ethers.js Error Messages

When working with Ethers.js, you may encounter various error messages that indicate issues with your transactions or interactions with the Ethereum blockchain. Understanding these errors is crucial for debugging and improving user experience. Below are some common error messages you might encounter, along with their meanings and possible solutions.

Common Error Messages

  • INVALID_ARGUMENT:

    This error occurs when an invalid argument is passed to a function. It can happen if the argument type is incorrect or if the value is out of range.
    Example: Passing a string instead of a number.

  • UNPREDICTABLE_GAS_LIMIT:

    This error indicates that the gas limit for the transaction cannot be estimated. This can happen if the transaction would fail or if there is an issue with the contract code.
    Example: Trying to call a function that reverts due to a require statement.

  • NETWORK_ERROR:

    This error occurs when there is a problem connecting to the Ethereum network. It may be due to network issues or incorrect provider configuration.
    Example: The Ethereum node is down or unreachable.

  • CALL_EXCEPTION:

    This error indicates that a contract call failed. It usually occurs when a smart contract function reverts due to a failed condition.
    Example: A function called on a smart contract that requires a certain condition to be met.

  • INSUFFICIENT_FUNDS:

    This error occurs when the sender's account does not have enough Ether to cover the transaction amount and gas fees.
    Example: Attempting to send Ether without sufficient balance.

Sample Code for Error Handling

Below is a simple HTML example demonstrating how to handle common errors in Ethers.js when sending a transaction: 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Ethers.js Error Handling Example</title>
    <script src="https://cdn.jsdelivr.net/npm/ethers@5.7.0/dist/ethers.umd.min.js"></script>
</head>
<body>
    <h1>Send Ether with Error Handling</h1>
    <input type="text" id="recipientInput" placeholder="Enter recipient address" />
    <input type="number" id="amountInput" placeholder="Enter amount in ETH" />
    <input type="text" id="privateKeyInput" placeholder="Enter your private key" />
    <button id="sendButton">Send Ether</button>
    <pre id="transactionInfo"></pre>

    <script>
        async function sendEther() {
            const provider = new ethers.providers.Web3Provider(window.ethereum);
            const recipient = document.getElementById('recipientInput').value;
            const amount = document.getElementById('amountInput').value;
            const privateKey = document.getElementById('privateKeyInput').value;

            // Create a wallet instance
            const wallet = new ethers.Wallet(privateKey, provider);

            // Create a transaction object
            const tx = {
                to: recipient,
                value: ethers.utils.parseEther(amount) // Convert amount to Wei
            };

            try {
                // Send the transaction
                const transactionResponse = await wallet.sendTransaction(tx);
                document.getElementById('transactionInfo').innerText = "Transaction Sent: " + transactionResponse.hash;

                // Wait for confirmation
                const receipt = await transactionResponse.wait();
                document.getElementById('transactionInfo').innerText += "\\nTransaction Confirmed in Block: " + receipt.blockNumber;
            } catch (error) {
                // Catch and handle errors
                if (error.code === ethers.errors.INVALID_ARGUMENT) {
                    document.getElementById('transactionInfo').innerText = "Invalid argument: " + error.message;
                } else if (error.code === ethers.errors.UNPREDICTABLE_GAS_LIMIT) {
                    document.getElementById('transactionInfo').innerText = "Unpredictable gas limit: " + error.message;
                } else if (error.code === ethers.errors.NETWORK_ERROR) {
                    document.getElementById('transactionInfo').innerText = "Network error: " + error.message;
                } else if (error.code === ethers.errors.CALL_EXCEPTION) {
                    document.getElementById('transactionInfo').innerText = "Call exception: " + error.message;
                } else if (error.code === ethers.errors.INSUFFICIENT_FUNDS) {
                    document.getElementById('transactionInfo').innerText = "Insufficient funds: " + error.message;
                } else {
                    document.getElementById('transactionInfo').innerText = "Error: " + error.message;
                }
            }
        }

        document.getElementById('sendButton').onclick = sendEther;
    </script>
</body>
</html>

Conclusion

Understanding common error messages in Ethers.js is essential for effective debugging and improving the user experience. By implementing proper error handling in your applications, you can provide users with clear feedback and ensure that your application behaves reliably even in the face of errors.