Smart Contract Testing & Debugging: Best Practices for Web 3.0 Builders

Smart Contract Testing & Debugging: Best Practices for Web 3.0

The security and reliability of any software product highly depend on the quality of its source code. When it comes to blockchain-based products, checking every single possible variable is essential, with a particular emphasis given to smart contract testing. 

Once the smart contract is deployed, changes are difficult, and transactions are permanent. If some issues are overlooked, it can result in notable reputational and financial losses for a business. That said, the IdeaSoft team has prepared a simple overview of smart contract debugging that explains how to test smart contracts, which tools to choose, and what aspects to check when building your perfect blockchain solution

Let’s dive in!

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Reach out to our team, and we will consult the best solution for your business, taking into account your product requirements and budget.

Table of content:

  1. How Do You Debug a Smart Contract?
  2. Best Practices for Smart Contract Testing and Debugging?
  3. What Are The Best Debugging Tools to Use with a Smart Contract?
  4. Essential Smart Contract Debugging Tips from IdeaSoft
  5. Our Experience
  6. Summary

How Do You Debug a Smart Contract

The standard process of smart contract debugging involves a series of steps aimed at ensuring the reliability, functionality, and security of the code. To help you understand its core principles, here’s a simple overview of how smart contracts are tested at IdeaSoft before they’re deployed in the blockchain: 

  1. Review the Requirements (optional): Our testing team double-checks the business requirements and technical specifications of the smart contract, defining its expected functionality, input parameters, and desired outcomes.
  2. Unit Testing: We test specific functions and methods within the smart contract in an isolated environment, ensuring they work as intended and return the expected results.
  3. Integration Testing: Our specialists check interactions between different functions within the contract and with external contracts or dependencies. Ensure that data flows correctly and that interactions meet requirements.
  4. Functional Testing: Through a full range of testing scenarios, we verify that the smart contract meets its functional requirements to ideally match your business needs.  
  5. Security Testing: Our developers identify and address potential vulnerabilities of the smart contract code by using techniques like static/dynamic analysis tools, code review, and commonly occurring issues.
  6. Documentation: Our team creates comprehensive documentation explaining the contract’s functionality, usage, and potential edge cases that will help to manage and optimize your smart contracts in the future. 
  7. Final Verification: Once all issues are resolved and tests pass successfully, our specialists confirm the smart contract is ready for deployment to your blockchain project.

Now that you’ve learned the basics of how smart contract debugging is performed and what areas it covers. In the next paragraphs, we’ll discuss the best practices for smart contract testing and tools that will help you come up with an ideal tech solution for your blockchain application. 

Best Practices for Smart Contract Testing and Debugging

There are different approaches and recommendations on how you can debug a smart contract. For this reason, the IdeaSoft team highlighted the most essential hacks that can enhance your smart contract checkup. 

#1 Use Automated Testing Tools

One of the most effective approaches in smart contract testing is to choose robust and user-friendly audit tools. The automated testing tools enable more efficient code checkups, helping to identify various errors, logic flaws, and unexpected behaviors in the early development stages. Additionally, this allows to save a lot of time, cost and human resources without sacrificing their quality. 

According to Rostyslav Bortman, the Head of Blockchain at IdeaSoft, the most effective dev environments for smart contract testing are Hardhat, Foundry, Tenderly and Truffle.

#2 Test for Security Vulnerabilities

Implementing regular updates and the latest practices in smart contract security can protect your application from potential malicious attacks and minimize its exposure to malware. 

The popular tools that help to identify weaknesses and common vulnerabilities in smart contracts are MythX, OpenZepplin, Goerli Testnet, and more

#3 Deploy Contracts on Multiple Networks

Testing contracts on various networks, such as testnets and private networks, allows developers to assess contract behavior under different scenarios. This practice is especially useful during performance testing, as it helps to capture more specific issues that might not be apparent in a single environment. At the same time, it helps to ensure your contract’s compatibility and validate its smooth performance across different blockchain networks.

#4 Document Your Tests

When learning how to debug smart contracts, documenting test cases, expected outcomes, and edge cases shouldn’t be overlooked as well. It aids in maintaining, understanding, and sharing your smart contract tests. Also, such an approach can improve the team’s collaboration and greatly help with future debugging and updates. 

Remember, well-documented checkups provide you with greater optimization ideas and insights, thus contributing to the longevity and reliability of your smart contracts.

What Are The Best Debugging Tools to Use with a Smart Contract?

Once we’ve uncovered the best practices for smart contract debugging, the next important aspect to discuss is choosing the tech stack for your code checkup. As of today, the most popular testing tools for smart contracts include: 

  • Truffle – an automated testing framework that covers multiple approaches (JavaScript/TypeScript or Solidity testing) to exercise different testing scenarios. Its in-built consoles (Truffle Console and Truffle Develop) are applied not only for interactive debugging purposes but also allow easy testing and executing transactions within a single environment.
  • Mythril – a security analysis tool for EVM bytecode that is commonly applied for Ethereum, Hedera, Quorum, Vechain, Roostock, Tron, and other EVM-compatible blockchains. 
  • Waffle – an advanced framework for smart contract testing that uses minimal dependencies, features an easy-to-learn syntax, and provides fast execution times for compiling and testing smart contracts. 
  • Hardhat – a powerful development environment for smart contracts on Ethereum that offers a comprehensive toolset for building, testing, and deploying contracts. 
  • Tenderly – a feature-rich development tool that allows you to build, test, monitor, and operate smart contracts from their inception to mass adoption. This tool supports over 30 different networks and is extremely helpful in strengthening the security of every Web 3.0 project. 
  • Immunefi – a functional bounty platform for smart contract and DeFi solutions that helps testers review code, address vulnerabilities, and improve the overall safety of crypto projects. 

Depending on the project’s complexity, functionality, and architecture specifications, all the smart contracts are tested in different ways. To maximize the reliability and security of your blockchain solution, it’s important to choose the most relevant technologies with your business goals and project requirements in mind. 

By outsourcing smart contract development to IdeaSoft, you’ll access the advanced debugging tools and the professional blockchain development expertise that fully matches your project. For each of our products, we identify the most relevant tools and effective testing approaches to ensure it’s robust, safe, and bug-free.

Essential Smart Contract Debugging Tips from IdeaSoft

Smart contract debugging is a complex process that has different nuances, considerations, and development challenges. To help you successfully get these covered, our Head of the Blockchain Department – Rostyslav Bortman, has prepared the key recommendations aimed at facilitating and improving the process of contract testing. 

  1. Make sure to achieve the unit test coverage near 100%;
  2. While conducting the checkups, it’s crucial to cover all cases for the function (both positive and negative);
  3. Use console.log where it’s supported. In particular, this can be performed through the Hardhat and Foundry debugging tools;
  4. Use forks of the networks instead of real networks. For example, you can try forking Goerli Testnet with Hardhat and running tests on the fork. This allows to speed up the testing process and reduces the need to search for the ETH;
  5. Use forks (for example, Hardhat fork) for simulation testing, as it allows you to impersonate any account (since you can use any address without a private key) and also aids in performing time manipulation tricks – which can be exceptionally important in some cases;
  6. For rigorous debugging, we recommend using Tenderly, which is so far one of the most efficient tools used for smart contracts;
  7. If the protocol you need for the tests doesn’t support forking (the EVM networks like zkSync or similar ones), you can use mock contracts to simulate the behavior of external contracts, components, or systems;
  8. Ensure that your test cases include boundary tests. For example, if there’s a function that works with numbers, test it with maximum and minimum possible values;
  9. Look for opportunities to optimize the gas fees. In particular, this can be achieved through reducing the number of used variables, storage cleaning, replacing dynamic arrays on fixed-size options, avoiding triple-nesting cycles and double-nesting cycles (if possible), and so on. 

These simple smart contract testing tips can help not only enhance the contract checkup but also ensure smooth operation and efficient performance upon its deployment in the blockchain. 

If you lack some expertise in how to debug smart contracts properly, don’t hesitate to ask for professional assistance. The tech-savvy engineers from a reputable development company such as IdeaSoft can help you to test, debug, and deploy the best smart contract solutions to the project you need.

Our Experience

With years of expertise working in blockchain development, our dedicated specialists have a deep understanding of smart contract architecture, its testing, and debugging. Currently, we don’t offer smart contract audit as a service, but each of our smart contracts is rigorously tested by our professional blockchain team, ensuring it’s always efficient, secure, and bug-free. 

In particular, we have successfully implemented smart contract solutions for the LiveCGI streaming platform, N-Finity NFT marketplace, BridgeTower marketplace and other projects, which can be found in our portfolio. Our team creates a powerful development strategy and conducts rigorous performance checkups to ensure the product operation is smooth, efficient, and completely secure.  


When developing any smart contract solution, conducting a thorough code checkup is essential. Smart contract debugging is a complex process that involves plenty of tools, frameworks, and techniques aimed to effectively address any code vulnerabilities and issues. As a result, it helps to greatly enhance the security and reliability of the final blockchain-based product.

At IdeaSoft, we have deep expertise in creating robust and functional smart contract solutions for a wide range of projects. With over 250 successful cases in IT development, our mission is to build secure products that provide the maximum value and will never be hacked. 

If you need professional guidance on smart contract debugging or need some more information about the other development services – contact us right away! Our experienced specialists are always ready to build a custom testing strategy with your business goals and needs in the first place!

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    Rostyslav Bortman
    Rostyslav Bortman
    Head of Blockchain Department
    Rostyslav is a blockchain developer with 7 years of experience in the field and deep expertise with web3 project architecture building and solidity smart contracts development. Rostyslav has successfully completed over 50 projects, and last year turned his main focus toward dApp development in particular.

    Frequently Asked Questions

    • What are the types of smart contract testing?
      There are three essential stages of smart contract testing that are commonly used in web 3.0 products: unit testing, integration testing and system testing. Some other debugging approaches in smart contract development can include: static/dynamic code analysis, security testing, gas usage analysis, formal verification, regression testing and user acceptance testing (UAT).
    • What types of vulnerabilities can arise within a smart contract debugging?
      Based on our rich experience in testing and debugging smart contracts, the common development issues include: reentrancy attacks, integer arithmetic errors, integer overflow/underflow, incorrect calculations in token outputs, front-running errors, timestamp dependence, access and privilege control issues.
    • Is there a difference between Rust and Solidity debugging?
      Overall, Rust debugging focuses on memory safety and low-level issues, while Solidity debugging mainly deals with logic errors, vulnerabilities, gas optimization, and contract interactions. Additionally, Rust and Solidity languages require different tools and development approaches to ensure efficient and bug-free smart contract solutions.
    • What are the best tools for smart contract debugging?
      Some of the most powerful tools used for smart contract testing and debugging include Hardhat, Truffle, Tenderly, Mythril, Sithler and Ethereum Studio. At IdeaSoft, we always take into account technical specifications, functionality, potential challenges and related aspects of each of our projects, helping to enhance the troubleshooting process and maximize the effectiveness of smart contract testing.

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