Code reviews are a critical part of the software development process, ensuring that code is not only functional but also maintainable, secure, and scalable. A well-executed code review can improve collaboration between team members. But when it comes to code reviews, there are two main approaches: self-review and peer reviews. Both are essentials for different reasons but each has its own set of best practices to ensure effectiveness. In this article, we’ll explore the best practices for code reviews, and how to conduct self-reviews and peer reviews properly which will help you write better code and work more efficiently with your team.
Why are code reviews important?
Code reviews are important for several reasons::
- Improve Code Quality: By reviewing code, potential issues such as bugs, security vulnerabilities, and inefficient algorithms are identified early.
- Encourage communication: Code reviews improve communication between team members, which fosters learning and knowledge sharing.
- Maintain Consistency: Consistency in code style and best practices is crucial for long-term maintainability. Code reviews ensure that everyone follows the same guidelines.
- Encourage Best Practices: Regular code reviews encourage adherence to best practices and standards, which ultimately improves the entire development process.
Difference between self-code review vs Peer Code Review
While both self-review and peer review aim to improve code quality, they differ in level of involvement.
Self-reviews are conducted by the developer who wrote the code. It’s a personal check to ensure the code is functional, readable, and follows the best practices.
Peer reviews, on the other hand, involve one or more team members reviewing the code written by someone else. Peer reviews provide a fresh perspective, helping to catch issues that might be overlooked by the original developer.
Follow the 3W approach before reviewing the code
Before diving into the details of a self-code review, ask yourself three questions to guide your process.
- Why: Why are you reviewing this code? Is it to check for functionality, readability, or performance? Understanding the review will help you focus on the right areas.
- What: What exactly are you reviewing? Are you looking at small changes or a large feature? Knowing the scope of the code will guide your approach and help you decide whether you need to conduct a detailed review or just a quick check.
- When: When should you do a code review? Ideally, self-review should be done after writing the code but submitting it for peer review. Reviewing it too early may not be productive while reviewing it too late may lead to missed issues.
Note for you: “The goal of a code review isn’t to prove you’re right, but to ensure that the code works well for everyone.”
Best Practices for Self-Code Review
Self-reviews are a crucial part of the development process, they ensure that the code you submit for peer review is polished, well-structured, and adheres to the coding standards. Below are the detailed tips to make your self-code review more effective.
1. Take a Break to Gain a Fresh Perspective Before Reviewing
When you write code, you’re too close to it, which can make it difficult to spot mistakes. After completing your work, take a break before you begin self-review. Whether it’s a few hours or just a short walk, stepping away from the code allows you to come back with fresh eyes. This distance helps you catch errors that might have been overlooked in the heat of coding and allows you to view your code more objectively.
2. Develop a Comprehensive Code Review Checklist
A checklist ensures you don’t miss any important aspects during your review. It should include:
- Readability: Is the code simple to read and understand? Are function and variable names descriptive and clear? Have you broken down complex logic into smaller, more manageable functions?
- Reusability: Have you checked if the code can be reused elsewhere? Are there any existing functions or modules that could accomplish the same task?
- Consistency: Are variable names consistent? Is the code easy to follow?
- Error Handling: Are all possible errors accounted for? Are exceptions handled properly?
- Efficiency: Are there any opportunities to optimize the code for performance?
- Code Style: Does the code follow your team’s style guide? Are indentation and spacing consistent?Security: Have you considered security implications, like input validation or potential vulnerabilities?
- Edge Cases: Have you considered potential edge cases in the logic? Are there scenarios where the code could fail or behave unexpectedly?
- Documentation: Is the code well-documented? Are complex or non-obvious sections explained with comments?
- Version Control Practices: Are your commits properly structured and descriptive? Have you used meaningful commit messages that explain the purpose of the changes?
- Dependency Management: Have you reviewed the dependencies used in your code? Are there any unnecessary or outdated dependencies that should be removed or updated?
- Scalability: Will the code perform well as the application grows? Have you considered the impact of your changes on performance as data volume or traffic increases?
Follow the above checklist and then implement it in the code. Creating a checklist according to your team’s coding standards will make the review process faster and more thorough.
3. Focus on One Aspect at a Time
Code is often complex and interrelated, but during a self-review, focusing on one aspect at a time helps maintain clarity. For example, first check for syntax errors, then move on to logic and finally focus on style and readability. If you review everything at once, you’re likely to miss important issues. By focusing on individual areas in turn, you can perform a more efficient and comprehensive review.
4. Write Code with Readability in Mind
Good self-review starts with writing code that is easy to review. When writing your code, think about readability. Use descriptive variable and function names, avoid complex, nested logic, and break long functions into smaller, more manageable ones. When your code is easy to read, it reduces the time needed for review and helps your teammates (and you) identify bugs or inefficiencies more quickly.
5. Conduct a Thorough Line-by-Line Review
A thorough read-through is necessary to ensure your code is complete and correct. Don’t just skim over it. Read each line carefully, check for off-by-one errors, confirm that all logical branches are properly addressed, and make sure that every function does what it’s supposed to do. Pay attention to edge cases and review whether your solution handles them appropriately.
6. Utilize Automated Tools for Initial Review
Automated tools like linters or code formatters can help catch errors you might miss during a manual review. For instance, tools like ESLint (for JavaScript) or PyLint (for Python) can highlight issues like unused variables, inconsistent formatting, and potential bugs. While these tools are not foolproof, they provide a good first layer of defense and can help you focus your manual review on the more complex aspects of your code.
7. Submit Small, Incremental Changes
It’s easier to spot issues and provide meaningful feedback when you’re reviewing small code changes rather than large, sprawling code submissions. Aim to submit small, incremental changes rather than large, monolithic updates. This will make your self-review process more manageable and also make it easier for your peer reviewers to understand and provide feedback.
8. Group Related Changes Together
If you’re making several changes to related parts of the code, try to group those changes in the same commit or pull request. This allows both you and your reviewer to understand the changes in context. For example, if you’re adding a feature that requires modifications to multiple functions, it’s easier to review those changes together than to scatter them across different parts of the codebase.
9 Check for Reusable Code Before Writing New Functions
Before writing new functionality, check if any existing libraries, functions, or classes in your codebase can be reused. Reusing existing code not only saves time but also helps maintain consistency across the project. If you’re unsure whether something can be reused, it’s always a good idea to ask your peers for input.
10. Write a Description of What the Code Change Is About
Before submitting your code for peer review, include a brief description of what the change is intended to achieve. This description will give context to your reviewers and help them understand the purpose of the changes. You should also explain any non-obvious decisions you made, such as why you chose one approach over another, and any potential trade-offs.
11. Run Tests to Ensure Code Integrity
Before submitting your code for review, make sure that all relevant tests are passing. Run your unit tests, integration tests, and any other applicable automated tests to ensure that your changes don’t break existing functionality. Additionally, manually test edge cases or any complex interactions that may not be covered by your automated tests.
12. Don’t Skip Reviews for Minor Changes
Even seemingly trivial changes, such as fixing a typo or refactoring a single line of code, should be reviewed. While these may seem like low-priority tasks, overlooking them could introduce errors or inconsistencies in the codebase. A small mistake now might lead to bigger issues later.
13. Offer Detailed Context for Reviewers
When submitting your code, always provide your reviewer with as much context as possible. For example, explain the problem you’re solving, how the code works, and if there are any areas where you’re uncertain. This allows the reviewer to focus on the right areas, saving time and making the review process more efficient.
14 Standardize with Pull/Merge Request Templates
To streamline the review process, consider using pull or merge request templates. Templates can ensure that you include all the necessary information, such as what was changed, why it was changed, and how to test the changes. This also helps maintain consistency across your codebase and makes it easier for your reviewer to understand the context of the code changes.
15. Complete Your Self-Review Before Submitting for Peer Review
Before submitting your code for peer review, ensure that you’ve completed a thorough self-review. This increases the quality of the code you submit and reduces the amount of rework needed during the peer review process. Submitting unreviewed code can lead to unnecessary confusion, delays, and frustration for your reviewers.
16. Be Open to Feedback
The primary goal of code reviews is to improve the quality of your work. Be open to feedback and suggestions from your reviewers. Constructive criticism can be invaluable, and being receptive to it will help you grow as a developer. Remember, code reviews are not personal attacks—they are a tool for improvement.
Best Practices for Peer Code Review
Peer reviews offer a fresh perspective and help identify issues that might be overlooked in a self-review. By implementing these best practices, you can ensure that your peer reviews are constructive, efficient, and valuable for all team members.
1. Start Reviews Early, Not Just After Coding
Effective peer review isn’t just about reviewing completed code—it’s about collaborating early in the process. Encourage code reviews to begin before coding starts by discussing requirements, design, and architecture. This helps catch potential issues early and ensures that everyone is on the same page before development begins.
2. Limit Review Sessions to 200-400 Lines of Code
Long code reviews can be overwhelming and ineffective. When reviewing code, limit the number of lines to around 200-400 at a time. This makes the review process more focused and manageable, helping you to identify issues without getting bogged down by a large volume of code. Reviewing in smaller increments allows you to be more thorough and reduces the risk of overlooking important details.
3. Avoid Nitpicking Small Details
While it’s important to catch errors and inconsistencies, avoid nitpicking over trivial issues such as minor formatting discrepancies. Focus on larger concerns like logic errors, security risks, and maintainability. Excessive focus on small details can demotivate the developer and slow down the review process. Offer constructive suggestions where needed, but aim to keep feedback focused on significant issues.
4. Provide Clear Justifications for Your Feedback
Whenever you provide feedback, be sure to explain why you’re suggesting a change. Avoid vague statements like “This doesn’t look good.” Instead, clarify your reasoning by offering an explanation of the problem and your recommended solution. For example, “This loop can be optimized because it’s currently running inefficiently and can be replaced with a more efficient algorithm.” This gives the developer a chance to understand your point of view and improves the quality of the review.
5. Encourage Knowledge Sharing
Peer reviews are an excellent opportunity for knowledge sharing. They allow more experienced developers to pass on their expertise, while also giving junior developers a chance to learn and contribute. Create an environment where everyone feels comfortable asking questions and discussing different approaches to solving problems.
6. Keep Review Sessions Concise and Focused
Long review sessions can lead to fatigue and reduced attention to detail. To keep the process productive, aim to keep code review sessions under an hour. If the review is taking longer, consider breaking it up into smaller sessions. This helps keep the review focused and ensures that everyone remains engaged throughout the process.
7. Ask Questions and Provide Context When Necessary
When reviewing code, ask questions if something is unclear. Rather than simply pointing out an issue, ask the developer to explain their reasoning or the purpose behind a particular approach. This encourages constructive discussion and allows the reviewer to understand the developer’s thought process.
8. Distribute Code Review Responsibilities Across the Team
Avoid overloading a single person with all the code reviews. Distribute code review requests among the team to ensure that everyone participates in the process. This not only spreads the workload but also helps ensure that a variety of perspectives are brought to the review, which leads to higher-quality feedback.
9. Follow Up and Iterate on Feedback
Code reviews are an iterative process. After providing feedback, it’s important to follow up to ensure that the feedback has been addressed. Developers should update their code and resubmit it for further review if necessary. By maintaining an open line of communication and continuing the review process until all concerns are addressed, you can ensure that the final code is of the highest quality.
Conclusion
Code reviews are an essential part of the development process, whether they’re self-reviews or peer reviews. By following the best practices outlined in this article, you can ensure that your code is of the highest quality and that the review process is smooth and effective.
Code reviews are about collaboration and improvement, not criticism. By adopting a constructive approach, you contribute to a culture of continuous learning and development within your team.
