Testing & Debugging

This guide provides comprehensive instructions on how to test and debug Aave protocol integrations.

There are two primary methods for testing the Aave protocol: using a testnet or creating fork networks.

The Aave protocol is available for testing on the Sepolia testnet. You can access the Sepolia V3 testnet market by visiting app.aave.com and enabling testnet mode in the top right corner.

To get started:

A fork network replicates the state of a blockchain, allowing you to interact with it in a sandbox environment. This is especially useful for testing scenarios that depend on contracts and states existing on the mainnet.

Several tools can help you create a fork network:

To acquire tokens on a fork network, you can impersonate an address that holds the desired tokens (holders can be found using block explorers) and transfer them to your address.

The app.aave.com interface can be configured to connect to a fork network. By setting specific variables via the browser console, you can enable this functionality. Refer to this guide for detailed instructions.

When interacting with the Aave protocol, you may encounter smart contract errors. This section helps you understand how to interpret error codes, use debugging tools, and resolve common issues.

The Aave protocol uses specific error codes to indicate why a transaction failed. Understanding these codes is essential for debugging. The error codes for each Aave protocol version are defined in their respective Errors.sol files:

To effectively debug transactions, you can use tools like Tenderly, Hardhat, and Foundry. These tools allow you to simulate transactions, inspect state changes, and step through execution to identify issues.

Tenderly allows you to simulate transactions and debug them step-by-step. By inputting the transaction details (to, from, data, and value), you can simulate the call and identify the cause of any revert, including error codes and stack traces.

Hardhat provides a local Ethereum environment for testing and debugging. It offers features like console logs in Solidity, detailed stack traces, and the ability to fork mainnet state for testing.

Foundry is a fast, portable, and modular toolkit for Ethereum application development. It includes tools like Forge for testing and debugging smart contracts, allowing you to simulate and debug transactions effectively.

The "Gas estimation failed" error is a generic message indicating that the transaction would fail if executed. To diagnose this issue:

When interacting with the Aave V3 Pool, you may encounter issues related to token approvals, insufficient collateral, or reaching protocol limits.

ERC-20 Token Approval for Supply and Repay

Before supplying or repaying tokens, ensure that you have granted the Aave Pool contract an allowance to transfer tokens. This is performed by calling the approve function on the ERC-20 token contract to authorize the Pool as the spender.

Insufficient Collateral

If you're unable to borrow assets, it may be due to insufficient collateral or not meeting the required Loan-to-Value (LTV) ratios. Ensure that you have supplied enough collateral and that it satisfies the protocol's requirements.

Borrow Cap Reached

Sometimes, you may not be able to borrow a specific asset because the borrow cap has been reached. In this case, you may need to wait for borrowers to repay or supply more liquidity to the pool.

For more detailed explanations of potential revert cases, refer to this DeFi Integration Guide.

Loan To Value = 0%

When an Aave reserve has a Loan To Value (LTV) parameter configured to 0%, commonly referred to as LTV0, it impacts reserve interactions in several ways:

When interacting with Ether (ETH) in the Aave protocol, the WrappedTokenGateway is used to wrap ETH into WETH and vice versa. Common issues may include not sending ETH with the transaction when required or using incorrect functions for depositing or withdrawing ETH.

For detailed usage and potential revert causes, refer to the WrappedTokenGateway documentation.