This guide can help you find that nasty bug troubling you and the tools to rectify them.
Debugging is crucial to any software development cycle; humans always make errors. That’s why we are unbeatable; we make errors and learn from them. Debugging is a process of figuring out where our code is lagging, fixing that, and learning about that error so that it is not repeated.
Smart contract development is crucial to building blockchain applications. But as with any other software development cycle debugging smart contracts can sometimes be challenging, and as here we often deal with a huge amount of money, we cannot leave anything to chance. We have to be perfect at writing smart contracts and perfect at debugging. That’s why we have come up with this blog so that you can learn about debugging from the best.
Before fixing anything, we need to know the issue, so let’s begin with identifying different types of bugs in smart contract development.
Common Errors
In this section, we will explore different types of bugs smart contract developers come across regularly.
- Syntax error:– This error is an easy one to fix. This happens when a developer makes a code mistake that prevents the computer from understanding it, like missing a semicolon.
- Logical Error:- This type of error can sometimes be hard to find. It does not prevent the execution, but the programme’s functionality is altered. This programme behaves unexpectedly like a smart contract that transfers money to the incorrect address when sending money from one account to another.
- Runtime error:- These errors are hard to predict. They come at an unexpected time and unexpected places. This occurs during the execution of smart contracts and happens due to inefficient exception handling. For example, this may occur when a contract fails to handle unexpected inputs or attempts to carry out an operation prohibited by the underlying blockchain. For example, a contract is trying to transfer more money than the allowed parameter.
- Execution Reverted Errors:- This happens when the user makes any illegitimate request that is against the smart contract’s logic then the request is canceled and reverted. This happens because sometimes smart contracts require certain requirements to be met to process the transaction. Still, the user proceeds with the transaction without fulfilling the requirements, and then the transaction is not carried forward and reverted. For example, a user is trying to transfer $100 but has a $50 balance.
- Stack Overflow:- The resources for executing the operations cost a gas fee. The heavy the function, the more the cost. Some of the heavy mechanisms in coding are loops and recursive calls. Stack overflow has to do with recursive calls. Recursive calls are a method of invoking a function within the same function with different inputs You can think of a recurring function as the sugarcane juice machine. The machine behaves as a function and the sugarcane as input. Each run of sugarcane from the machine means a function call. After one time, the sugarcane goes under the machine again, and this process keeps repeating. This is what recurrence is. But as we want to cut on gas costs and EVM resources, ethereum limits the recurrence call up to 1024 times. When you call a function 1025th time, it results in a stack overflow.
- JUMP error:- When you try to call a function that does not exist or use assembly language and point to false memory, this results in an error. This can even happen when you call a function of some other contract, but that function does not exist. These types of errors are called JUMP errors.
These were some common smart contract errors developers encounter; errors can sometimes be hard to detect and understand. To find the errors and try to fix them, we take the help of various tools. Let us go through them one by one in the next section.
Four Useful Debugging Tools
In this section, we will learn about tools heavily used to identify and resolve bugs by most experienced developers worldwide. Let’s go.
Hardhat
This tool is widely used and accepted for testing smart contracts on various parameters. It provides an open-source development environment for Ethereum. It includes tools for developing, testing, and deploying smart contracts. Its built-in debugger is helpful to many developers around the world. This plays a heavy role in the testing phase too.
Truffle
This is a popular development framework for Ethereum. Like hardhat, it includes tools for developing, testing and deploying smart contracts and also has built Truffle Debugger, which helps developers with a smooth development experience in the testing stage.
Remix
This is the one which almost every developer came across when they first started their journey in web3. This is an online code editor for solidity, so no offline installation is needed to begin with development. Its built-in debugging feature lets developers scan the code and inspect variable issues. And all of this is online no need for offline tools.
Etherscan
This is a widely trusted and popular block explorer for Ethereum. It allows developers to inspect and debug smart contracts deployed on the Ethereum blockchain. Using this, you can track transactions and activity of any address or contract. This helps you identify where the issue would be if your smart contract is facing any on-chain issues.
Conclusion
Debugging smart contracts is difficult and sometimes frustrating, but it is a crucial stage related to security and testing. This is where vulnerabilities are most likely to present themselves to hackers and can lead the protocol to complete failure. To save yourself from such circumstances, it is highly advised to go for audits.
QuillAudits has been in this vertical for a long time and has an expert team that can handle every possible vulnerability and help you secure your protocol. Regarding the testing, its importance, and its relation with debugging, read the detailed blog, which will help you understand every aspect https://blog.quillhash.com/2023/02/16/testing-and-formal-verification/. Do visit our website and get your project audited!
