Code Review: The Ultimate Guide

Code Review is one of the most important processes that can lead to a high-quality software. Not only that but it’s also important for many other things inside a software project. Things such as knowledge sharing between team members and also improving the spirit of collaboration. I’ve already written a short article about code review and introduce some best practices. You can find the aforementioned article here. My goal in this article is to give a very comprehensive look on the subject of code review. I’m going to discuss the values it can brings which is not directly related to software quality. I’m also going to introduce a lot of tips that improves how code review is done. Especially when it comes to the human and social aspects of code review. So, if that interests you, please keep reading.

What is Code Review and why it’s important?

First, I think it’s best to talk about why code review is important. Hopefully we can understand why we should care about this process. I’m going to talk about the different important advantage that code review can give us. So, let’s start by defining code review.

Code review is a process in software development where one or more developers review the code written by another developer. Code reviews have become an essential part of the software development process as they offer several benefits, including:

Improve code quality: Code reviews can help identify and fix errors, bugs, and vulnerabilities in the code. This leads to higher quality code that is more reliable, easier to maintain, and less likely to cause problems in production.

Knowledge sharing: Code reviews provide an opportunity for developers to share their knowledge and learn from each other. By reviewing code written by others, developers can learn new techniques, best practices, and coding standards. Code review should be a learning experience for all team members. Reviewers should share their knowledge and expertise with others, and developers should be open to feedback and willing to learn from mistakes.

Consistency: Code reviews ensure that the code follows the company’s coding standards and guidelines, leading to consistent code across the codebase.

Faster development: While code reviews can take time, catching issues early in the development process can save time and money in the long run. Code reviews can help identify issues that may cause delays in the future and allow developers to address them before they become bigger problems.

Collaboration: Code reviews promote collaboration among developers. By reviewing code written by others, developers can provide feedback, ask questions, and work together to improve the code.

In summary, understanding the benefits of code review is important because it helps improve the quality of code, promotes knowledge sharing and collaboration, ensures consistency, and can lead to faster development.

Foundations and Prerequisites Necessary for a Good Code Review Process

To do code review in a good and effective way, first some foundations and prerequisites elements need to exist first. Without these elements, code review becomes rather slow and ineffective process. So, it’s important to make sure we create a good environment where code review can take place first. In the following sections I’m going to talk about talk about these elements and provide some tips to improve them.

Code Review Foundations: Team communication

Effective communication is crucial for successful collaboration in a programming team. Here are some preconditions and ideals that can help facilitate good communication between team members:

Use clear and concise language: Communication should be clear and concise, with a focus on conveying information accurately and effectively. This includes using appropriate technical terminology and avoiding jargon or overly technical terms or ambiguous language. This can help to ensure that everyone understands the feedback and can act on it.

Focus on specific issues: Focus on specific issues rather than general comments. This can help to make the feedback more actionable and reduce the risk of misunderstanding or misinterpretation.

Use examples: Use examples to illustrate your feedback, showing how the code could be improved or why a particular change is necessary. This can help to make the feedback more concrete and understandable.

Be constructive: Be constructive in your feedback, focusing on how the code can be improved rather than criticizing it. This can help to maintain a positive and collaborative atmosphere.

Be receptive to feedback: Be receptive to feedback yourself, listening carefully to what others have to say and taking it into account when making changes to the code. This can help to build trust and encourage others to be more receptive to your feedback in the future.

Use a consistent process: Use a consistent process for code review, including guidelines for how feedback should be given and how issues should be tracked and resolved. This can help to reduce confusion and ensure that everyone is on the same page.

Respect: Team members should treat each other with respect and professionalism, even when they disagree. This helps to maintain a positive working environment and encourages open communication. Code review should be a collaborative process where all team members respect each other’s opinions and ideas. Reviewers should not criticize the developer personally but focus on the code and how it can be improved.

Timeliness: Communication should be timely, with team members responding promptly to requests for information or feedback. This helps to keep the project moving forward and avoids delays. If there are delays in communication, it’s makes it hard for developer to respond to feedback. Because normally the developer needs to move on to other tasks, and when he/she finally receives the feedback, a context switch needs to happen to respond to the feedback.

Time and Resources: This one is an obvious, but very important point. Time and resources need to be dedicated to code review. That means the upper management of a software company needs to recognize the value of code review and try to encourage and embrace the practice. That means there are enough developers and resources available to be spent to the code review.

Priority of the Code Review: Code review is one of high priority processes in software development. So, it’s important to establish a set of guidelines or processes that ensure that code review is done regularly and consistently while also ensuring that other important activities are not neglected. Additionally, ensuring that tasks that are important and need code review immediately are separated from the tasks that are less important. One example is a code that is written to deliver a feature is more important than a code that is about refactoring certain aspect of the software project. It is also important for the team members to have the necessary skills and tools to effectively review code.

By using a consistent process, using clear and concise language, focusing on specific issues, using examples, being constructive, and being receptive to feedback, you can help improve communication in the code review process and ensure that everyone is working together effectively to develop high-quality code.

Code Review Foundations: Chatting Apps vs Pull Request Page

Another important aspect in communication is to the channels we use to communicate information. This is important because it can determine the accessibility of the feedback. Feedbacks given on the code review are valuable information that can be shared and accessed later for the purpose of learning and also auditing. So, should we use chatting apps like teams or slack for code review or is it better to use the pull request page which is more permanent?

Communication should be consistent, with team members using the same channels and tools to share information and collaborate. This helps to avoid confusion and ensures that everyone has access to the same information.

There are advantages and disadvantages to both communicating about code review on chatting apps and on the pull request page itself. But I think if we want to receive the most benefit, our decision should lean towards keeping our discussions about the code review on the pull request itself.

The code review process should be transparent, with all team members having access to the review process and feedback. This ensures that everyone is on the same page and can learn from the review process.

Disadvantages of communicating on chatting apps:

Lack of visibility: Conversations that happen on chatting apps are not always visible to the entire team, which means some team members may miss important information or decisions.

Difficult to track: Conversations on chatting apps can be difficult to track, especially if they happen across multiple channels or threads. This can make it hard to keep track of decisions and feedback.

No permanent record: Chatting apps don’t provide a permanent record of the conversation, which can make it difficult to refer back to previous discussions.

Advantages of communicating on the pull request page:

Transparency: Communicating on the pull request page ensures that all team members can see the feedback and decisions made during the code review process. This can help ensure that everyone is on the same page.

Easy to track: The pull request page provides a centralized location for all feedback and discussions, making it easy to track decisions and feedback.

Permanent record: All conversations on the pull request page are recorded and can be referred back to in the future. This can be helpful for future code reviews or audits.

Code Review Foundations: Clear requirements

Clear requirements are essential for good code review to take place for several reasons:

Standards for Evaluation: Clear requirements help establish standards for evaluating the code being reviewed. The requirements provide a clear understanding of what the code is expected to do, how it is expected to perform, and what issues to look out for. This ensures that the code is evaluated based on objective criteria and not based on personal preferences.

Consistency: Clear requirements help promote consistency in the review process. When the requirements are well-defined, all reviewers are working from the same set of expectations. This reduces the likelihood of subjective differences in the evaluation and ensures that the review process is consistent across the team.

Time Management: Clear requirements can help save time during the review process. When the requirements are clearly stated, reviewers can quickly identify if the code meets the requirements or not. This helps streamline the review process and allows reviewers to focus on identifying potential issues or improvements.

Avoiding Ambiguity: Clear requirements help avoid ambiguity and misunderstandings between the reviewers and the developers. This ensures that all parties are on the same page and that the code is being reviewed based on the same set of expectations.

Overall, clear requirements are critical for ensuring a productive and efficient code review process. They help establish standards, promote consistency, save time, and avoid ambiguity, which ultimately leads to better code and software products.

Code Review Foundations: Code Standards

By having coding standards in place can significantly help the process of code review in several ways:

Consistency: Coding standards help ensure consistency in the codebase by providing a common set of guidelines and best practices for all developers to follow. This makes it easier for reviewers to understand the code and identify issues or areas that need improvement.

Readability: Coding standards also help improve the readability of the code, making it easier to understand and maintain. This can reduce the time it takes for reviewers to review the code and provide feedback.

Quality: Following coding standards can also help improve the overall quality of the code by promoting good coding practices and reducing the likelihood of errors and bugs.

Efficiency: Having coding standards in place can also help streamline the code review process by reducing the time and effort required to review the code. This is because the code will be easier to understand and follow, reducing the need for reviewers to spend extra time trying to decipher complex or inconsistent code.

Overall, having coding standards can help ensure that the code review process is more effective, efficient, and productive, resulting in higher quality code and better software products.

Code Review Foundations: Review Process Guidelines

Guidelines for the code review process provide a framework for conducting code reviews in a consistent and effective manner. These guidelines typically outline the expectations and responsibilities of both the reviewer and the developer whose code is being reviewed. By stablishing these guidelines, we make sure that everyone understands what their responsibilities are and that in turn result in more streamlined and effective code process. It can also help those who are new to the team to understand and to get use to the code review process as fast as possible by having an express set of expectations for the code review. Here are some common guidelines for code reviews:

Focus on the code: Review the code and not the developer. Avoid making personal comments and instead provide constructive feedback on the code itself.

Be objective: Avoid making assumptions or being biased towards certain approaches. Use evidence and rationale to support your feedback.

Use a checklist: Have a standard checklist of items to review, such as coding conventions, security considerations, and error handling.

Provide actionable feedback: Be specific in your feedback and suggest ways to improve the code. Avoid making vague comments like “this code is bad.”

Follow up: Ensure that the developer incorporates the feedback and makes necessary changes before merging the code.

Guidelines for code reviews are important because they help ensure that the review process is consistent, thorough, and effective. They help developers understand what is expected of them and what they should look for when reviewing code. This, in turn, leads to better code quality and a more efficient development process.

Code Review Foundations: Respect

Respect is an essential aspect of code review because it helps to establish a positive and collaborative environment in which developers can share their work and provide feedback to each other. When people feel respected, they are more likely to be open to feedback and suggestions, and they are more likely to take those suggestions seriously.

Here are some specific reasons why respect is important in code review:

Encourages open communication: Respectful behavior encourages people to be more open and honest in their communication. When people feel respected, they are more likely to share their thoughts and ideas without fear of being judged or criticized.

Fosters teamwork: Code review is a team effort, and respect is essential for building strong and effective teams. When people respect each other, they are more likely to work together to solve problems and achieve common goals.

Promotes a culture of continuous improvement: Code review is not just about finding bugs or errors; it’s also about learning from each other and improving our coding skills. When people feel respected, they are more likely to take feedback seriously and use it to improve their work.

Helps to prevent conflicts: Code review can sometimes lead to disagreements or conflicts, but when people approach the process with respect, they are more likely to resolve those conflicts in a constructive and positive way.

In summary, respect is an essential aspect of code review because it promotes open communication, fosters teamwork, promotes a culture of continuous improvement, and helps to prevent conflicts. When people approach code review with respect, they create a more productive and positive environment that benefits everyone involved.

Code Review Foundations: Defensiveness and other Human Aspects

Code review can be a sensitive process, as it involves evaluating someone else’s work and identifying potential areas for improvement. Here are some tips to help create a good environment for code review where everyone feels safe to receive criticism without getting defensive:

Establish clear guidelines: Set clear guidelines and expectations for the code review process, including the purpose of the review, the types of feedback that are appropriate, and how feedback should be delivered. This can help to reduce confusion and anxiety.

Emphasize the importance of feedback: Highlight the importance of feedback as a tool for improving the quality of the code and achieving project goals. This can help to shift the focus away from personal criticism and toward constructive feedback.

Encourage a growth mindset: Encourage team members to adopt a growth mindset, in which they view feedback as an opportunity to learn and improve, rather than a personal attack. This can help to reduce defensiveness and increase receptiveness to feedback.

Use positive language: Use positive language to frame feedback, focusing on what can be improved rather than what was done wrong. This can help to reduce negative emotions and encourage constructive dialogue.

Avoid blaming and personal attacks: Avoid blaming or personal attacks, and instead focus on the code itself. This can help to reduce defensiveness and keep the conversation focused on the code and how it can be improved.

Foster a culture of collaboration: Foster a culture of collaboration and teamwork, where everyone feels valued and supported. This can help to reduce defensiveness and increase receptiveness to feedback.

By establishing clear guidelines, emphasizing the importance of feedback, encouraging a growth mindset, using positive language, avoiding blaming and personal attacks, and fostering a culture of collaboration, you can help create a safe and constructive environment for code review where everyone feels comfortable receiving feedback.

Code Review Other Aspects

Now that we’ve talk about the important non-technical aspects of code review, now it’s time to talk about the technical and functional aspects. In my view the technical and functional aspect of code review comes after the non-technical foundational aspects, because without those foundations, the code review process cannot take place. So, in the subsequent section, I’m going to go through these aspects and we’re going to see how we can improve those aspects.

Code Review: Functional Aspect

Checking the functional aspect of the code is extremely important in a code review. The functional aspect of the code refers to whether the code is fulfilling its intended purpose or not. Here are some reasons why it’s important to check the functional aspect in the code:

Ensure correctness: The primary goal of any software is to perform its intended function correctly. Checking the functional aspect of the code ensures that the code is functioning correctly and meeting the requirements.

Reduce bugs and errors: Incorrect functionality can lead to bugs and errors, which can be costly to fix. Catching these errors early in the code review process can save time and resources down the line.

Improve user experience: The functional aspect of the code directly impacts the user experience. If the code is not functioning as intended, users will have a poor experience, leading to dissatisfaction and lost revenue.

Meet business objectives: The functionality of the code is often tied to business objectives. If the code is not functioning correctly, it may not be meeting the business objectives, leading to lost revenue and missed opportunities.

Ensure compliance: Some software is subject to regulatory compliance requirements. Checking the functional aspect of the code ensures that it meets the compliance requirements and avoids any legal or financial penalties.

In summary, checking the functional aspect of the code is crucial to ensure that the code is fulfilling its intended purpose correctly, reducing bugs and errors, improving the user experience, meeting business objectives, and ensuring compliance.

Code Review: Technical Aspects

Technical aspect of a code review can have many facets. Each of these facets are important if we want to have a good code review process. I’m going to go into detail about each one of these aspects.

Code Quality

The reviewer should check the code for readability, maintainability, and consistency. The code should be easy to understand and modify.

Code quality is an important aspect of code review, and there are several things you can check for to ensure that the code is of high quality. Here are some ways to check for code quality during a code review:

Code formatting: Check if the code is properly formatted according to the coding standards and guidelines of the team. Inconsistent code formatting can make the code difficult to read and maintain.

Code readability: Check if the code is easy to read and understand. Complex code with convoluted logic can be difficult to follow, leading to errors and bugs.

Code duplication: Check if the code has any duplicated code blocks. Duplicated code is a sign of poor design and can make the code harder to maintain.

Code complexity: Check if the code is too complex. Complex code can be difficult to understand and maintain. Use tools such as cyclomatic complexity tools to check the complexity of the code.

Code comments: Check if the code has meaningful comments. Comments help other developers understand the purpose of the code, and they can be useful for debugging.

Code modularity: Check if the code is modular and well-organized. Modular code is easier to read and maintain than monolithic code.

Code coupling and cohesion: Check if the code has high coupling or low cohesion. High coupling means that the code is tightly coupled, making it difficult to modify. Low cohesion means that the code is scattered and lacks organization.

Code testing: Check if the code is well tested. Proper testing ensures that the code is working as intended and reduces the risk of introducing bugs.

Tools: Use tools such as static code analysis tools and code linters to check for code quality and compliance with coding standards. These tools can help to identify code quality issues and enforce coding standards.

Code structure

The code structure should be modular and organized. The reviewer should check if the code follows the best practices and design patterns.

Code structure is an important aspect of code review, as it affects the readability, maintainability, and scalability of the code. Here are some ways to check for code structure during a code review:

Modularization: Check if the code is properly modularized, with clear separation of concerns. Each module should have a clear and specific purpose, making it easier to maintain and test.

Code organization: Check if the code is organized logically, with related functions and data structures grouped together. This makes it easier to understand and navigate the code.

Naming conventions: Check if the code follows consistent and meaningful naming conventions. This helps other developers understand the purpose and function of each element in the code.

Code reuse: Check if the code is designed for reuse, with common functionality extracted into separate modules or functions. This reduces code duplication and makes the code more maintainable.

Code commenting: Check if the code is properly documented with comments that explain the purpose and function of each element. This helps other developers understand the code and makes it easier to maintain.

Code patterns and best practices: Check if the code follows established patterns and best practices, such as the SOLID principles or the DRY (Don’t Repeat Yourself) principle. This ensures that the code is maintainable and scalable over time.

Code complexity: Check if the code is too complex, with long and convoluted functions or data structures. This can make the code difficult to understand and maintain.

Code dependencies: Check if the code has too many dependencies on external libraries or services. This can make the code more brittle and difficult to maintain, especially if the external dependencies change or become outdated.

In summary, checking the code structure during a code review involves evaluating the modularization, organization, naming conventions, reuse, commenting, patterns and best practices, complexity, and dependencies of the code. By paying attention to these aspects, you can ensure that the code is readable, maintainable, and scalable over time.

Performance

The code should be optimized for performance. The reviewer should check for potential performance bottlenecks and suggest improvements.

Checking the code performance during a code review is important to ensure that the code is efficient and performs well under expected loads. Here are some ways to check for code performance during a code review:

Time complexity: Check if the code has an acceptable time complexity, especially for algorithms and data structures. Use tools such as big-O notation to estimate the worst-case time complexity of the code.

Space complexity: Check if the code has an acceptable space complexity, especially for algorithms and data structures. Use tools such as big-O notation to estimate the worst-case space complexity of the code.

Resource utilization: Check if the code uses system resources efficiently, such as memory, CPU, and network bandwidth. Use tools such as profiling to measure the resource utilization of the code.

Data caching: Check if the code uses data caching to reduce the number of times it needs to fetch data from external sources. This can significantly improve performance.

Code parallelism: Check if the code can be parallelized to improve performance, especially for CPU-bound tasks. Use tools such as multi-threading or distributed computing to parallelize the code.

Code optimizations: Check if the code has any performance optimizations, such as loop unrolling, vectorization, or compiler optimizations.

However, it’s important to note that premature optimization can be a problem during a code review. Premature optimization refers to optimizing the code for performance before it’s necessary, which can lead to code complexity, reduced readability, and increased development time. It’s important to focus on code performance only when it’s necessary and when there are clear performance goals and metrics to measure against. Otherwise, it’s better to prioritize code readability, maintainability, and scalability over performance.

Security

The code should be secure and not vulnerable to attacks such as injection, cross-site scripting, or cross-site request forgery. The reviewer should check for any potential security flaws.

Input validation: Check if the code properly validates all input from external sources, such as user input or data from APIs. This prevents attackers from injecting malicious code or data into the system.

Authentication and authorization: Check if the code properly authenticates and authorizes users and services accessing the system. This prevents unauthorized access and misuse of sensitive data or functionality.

Secure communication: Check if the code properly encrypts and authenticates communication between different components of the system, such as APIs, databases, or other services. This prevents eavesdropping, tampering, or other attacks.

Secure storage: Check if the code properly encrypts and protects sensitive data at rest, such as passwords, financial information, or personal data. This prevents unauthorized access to sensitive information.

Code injection: Check if the code is vulnerable to code injection attacks, such as SQL injection or cross-site scripting (XSS) attacks. These attacks can allow attackers to execute arbitrary code or steal sensitive data.

Vulnerability management: Check if the code properly handles known vulnerabilities in third-party libraries, frameworks, or other components. This prevents exploitation of known vulnerabilities that could compromise the security of the system.

OWASP (Open Web Application Security Project) is a great resource for code security during a code review. OWASP provides a comprehensive list of the most critical security risks that software applications are vulnerable to, along with best practices for mitigating those risks. The OWASP Top 10 is a well-known list of the most critical security risks that software developers and security professionals should be aware of. By using OWASP resources, you can identify potential security issues in the code and take the necessary steps to mitigate them before deployment.

Checking the Written Tests

The code should be tested thoroughly. The reviewer should check if the code is tested properly and if the tests cover all the use cases.

Checking for code testing during a code review is essential to ensure that the code has been properly tested and is robust. Here are some ways to check for code testing during a code review:

Test coverage: Check if the code has sufficient test coverage to ensure that all critical paths and edge cases are covered by tests. This can be measured using tools such as code coverage analysis.

Test quality: Check if the code tests are of good quality, such as being well-written, readable, and maintainable. This ensures that the tests themselves don’t introduce bugs or become a maintenance burden.

Test data: Check if the code has well-defined test data that can be used to simulate different scenarios and edge cases. Use tools such as test data management tools to manage and generate test data.

Test types: Check if the code tests cover different types of testing, such as unit tests, integration tests, and end-to-end tests. Each type of test has a different focus and scope:

Unit tests: Check the behavior of a small, isolated piece of code, such as a function or class. Unit tests should test the code in isolation from its dependencies.

Integration tests: Check the behavior of a group of components working together, such as a set of APIs or microservices. Integration tests should test the interactions between different components.

End-to-end tests: Check the behavior of the entire system, from the user interface to the back-end services. End-to-end tests should test the system from the perspective of the user.

Checking for code testing differs based on the type of test. For example, when checking for unit tests, you should look for test coverage and quality at the function or class level. You should also check that the tests are properly isolated from dependencies and are testing the expected behavior. When checking for integration tests, you should look for test coverage and quality at the API or microservice level. You should also check that the tests are properly testing the interactions between different components. When checking for end-to-end tests, you should look for test coverage and quality at the system level. You should also check that the tests are properly testing the entire system is tested from start to finish to ensure that it works correctly in real-world scenarios. When checking for end-to-end tests, focus on the completeness of test scenarios and data, and ensure that all critical functionalities are tested.

Documentation

The code should be well-documented. The reviewer should check if the code is well-documented and if the comments are meaningful.

Checking for code documentation during a code review is important to ensure that the code is well-documented and easy to understand for other developers who may work on the code in the future. Here are some ways to check for code documentation during a code review:

Comments: Check if the code has sufficient comments that explain the purpose of the code, how it works, and any assumptions or limitations. Ensure that the comments are accurate, up-to-date, and easy to understand.

Variable and function names: Check if the code uses meaningful variable and function names that convey their purpose and usage. Avoid using cryptic or ambiguous names that can make the code difficult to understand.

Function signatures: Check if the function signatures are well-defined and accurately describe their input and output parameters. Ensure that the function signatures are consistent and follow standard conventions.

API documentation: Check if the code has well-documented APIs that describe their functionality, input and output parameters, and usage. Ensure that the API documentation is accurate, up-to-date, and easy to understand.

Readme and other documentation files: Check if the code has well-written readme and other documentation files that provide an overview of the code, how to build and run it, and any dependencies or requirements. Ensure that the documentation files are accurate, up-to-date, and easy to understand.

Code structure: Check if the code follows standard conventions for code structure, such as using a consistent file and folder structure, properly organizing functions and classes, and using code comments to describe the purpose of different sections of code.

By checking for code documentation during a code review, you can ensure that the code is well-documented and easy to understand, reducing the time and effort required for future maintenance and development. Additionally, by ensuring that the code follows standard conventions for documentation and structure, you can promote consistency and maintainability across the codebase.

Version control

The code should be properly versioned. The reviewer should check if the code follows the best practices for version control.

Version control is an important aspect of code development, and it’s crucial to ensure that it’s implemented correctly during code reviews. Here are some tips to help you check for version control related stuff during a code review:

Check if the code has been properly versioned: Look at the commit history to ensure that the code has been properly versioned and that the commits have clear and concise messages. Check if the code follows a clear branching strategy and that it is properly tagged and labeled.

Look for code conflicts: Check if there are any conflicts or merge issues between different branches. Make sure that the code is properly tested and integrated before merging it into the main branch.

Review the pull request: Check if the pull request includes all the necessary information such as the description, the purpose of the change, the impact on the system, and any relevant issues or bug reports.

Breaking things to smaller parts: Sometimes the work done on a subject is very big and from the review we can understand if it needs to be broken down further to be able to receive a good code review

Check for code reviews: Look for previous code reviews and feedback from other developers. Review the changes made to the code and check if they have been implemented correctly.

Check for documentation: Make sure that the code is well documented, and that the version control system is properly documented as well. Check if there are any changes or updates to the documentation that need to be made.

Check for compliance: Check if the code follows the company’s version control policies and procedures. Ensure that the code adheres to the relevant standards, such as ISO/IEC 12207 for software development.

By following these tips, you can ensure that version control is implemented correctly during code reviews, which can help to prevent issues and errors down the line.

Automated Code Review, Analyzers and Continuous Integration

Continuous Integration

Continuous Integration (CI) is a development practice that involves regularly integrating and testing code changes as they are made, rather than waiting until the end of a development cycle to merge changes into the main codebase. This approach can have several benefits for the code review process:

Early Detection of Issues: By integrating code changes and running automated tests on a regular basis, CI can help catch issues early in the development process. This means that issues can be identified and fixed before they cause bigger problems downstream. In the context of code review, this means that reviewers can focus on more complex issues rather than spending time on simple problems that could have been caught earlier in the process.

Improved Collaboration: CI encourages frequent code commits and updates, which means that developers are working on the same codebase and can collaborate more easily. This can make the code review process smoother and more effective since developers are more likely to be familiar with each other’s work and can help each other resolve issues.

Faster Feedback: CI can provide rapid feedback on code changes, which can be helpful during the code review process. Automated tests can be run on every code change, and the results can be communicated to developers and reviewers quickly. This means that issues can be addressed more quickly and the overall development process can be more efficient.

Reduced Risk: By catching issues early and providing rapid feedback, CI can help reduce the risk of bugs and other issues making their way into production. This can save time and resources in the long run and make the code review process more effective by reducing the amount of time spent fixing issues that could have been caught earlier.

In summary, a good CI process can benefit the code review process by detecting issues early, improving collaboration, providing faster feedback, and reducing the risk of issues making their way into production. By incorporating CI into their development process, teams can make their code review process more effective and efficient.

Automated Code Review, Analyzers

Automated Code Review refers to the process of using software tools to automatically scan code and identify issues or inconsistencies. These tools use pre-defined rules or algorithms to check code against best practices, coding standards, and potential security vulnerabilities. Automated Code Review can be a powerful tool to save time and improve the code review process in several ways:

Catching Common Errors: Automated Code Review tools can help catch common coding errors, such as syntax errors or code that does not follow best practices. By catching these issues early in the development process, developers and reviewers can focus on more complex issues during the code review.

Enforcing Consistency: Automated Code Review tools can also help enforce coding standards and maintain consistency in the codebase. This can be especially helpful in large projects with multiple developers, where consistency can be challenging to maintain.

Improving Code Quality: By identifying issues that can lead to bugs or other problems, Automated Code Review can help improve the overall quality of the codebase. This can result in fewer bugs and issues making it to production, which can save time and resources in the long run.

Reducing Manual Effort: Manual code review can be time-consuming and resource-intensive. Automated Code Review can help reduce the amount of time spent on manual code review by catching issues early and providing automated feedback.

Enhancing Security: Automated Code Review tools can help identify potential security vulnerabilities in the codebase, such as SQL injection or cross-site scripting (XSS) attacks. By catching these vulnerabilities early in the development process, teams can work to address them before they become a serious security risk.

In summary, Automated Code Review can be a powerful tool to save time and improve the code review process. By catching common errors, enforcing consistency, improving code quality, reducing manual effort, and enhancing security, teams can make their code review process more efficient and effective.

Analyzers Example for C# and Javascript

Since these are the languages that I have the most familiarity with, I’m going to list some of the analyzers that I’ve used other the years to scan code and find problems automatically. These tools helped me save time during the code review and reduce manual efforts.

For C#:

  1. Roslyn Analyzers: This is a built-in code analyzer in Visual Studio that can detect security issues, coding style violations, and other problems in C# code. In this link you find some of most used analyzers that are supported by Microsoft.
  2. StyleCop: This is a code analyzer that checks C# code for style and consistency violations. It enforces a set of coding conventions and can help improve code readability and maintainability.
  3. ReSharper: This is a popular code analysis and refactoring tool for C#. It can detect a wide range of issues, including code smells, performance problems, and code style violations.
  4. CodeIt.Right: This is a tool that provides automatic code analysis and generates reports on coding standards, code quality, and best practices.
  5. SonarQube: This is an open-source platform for continuous code quality analysis that supports multiple languages, including C#. It provides code coverage, code duplication analysis, and security analysis.

For JavaScript:

  1. ESLint: This is a popular code analyzer for JavaScript that can detect errors, potential security vulnerabilities, and coding style issues.
  2. JSHint: This is a code analyzer that checks JavaScript code for syntax errors, coding style issues, and potential security vulnerabilities.
  3. SonarQube: As mentioned above, SonarQube also supports JavaScript code analysis and can detect security issues, code quality issues, and maintainability issues.
  4. CodeClimate: This is a cloud-based platform that provides automated code analysis for JavaScript and other programming languages. It can detect a wide range of issues, including code complexity, maintainability, and security vulnerabilities.
  5. Prettier: This is a code formatter and style checker for JavaScript that enforces consistent code style and improves code readability. It can be integrated into development workflows to ensure consistent code style across teams.

Overall, using these code analyzers can help ensure high code quality, improve security, and maintain consistency in coding style.

Before Submitting the Changes for Code Review by the Author

There are some steps as the author of the code that can smooth the process of code review for the reviewer. This are the steps we take before submitting the code for code review. It’s also worth mentioning that this step can also be defined in our definition of done (DOD). That will make sure there are no ambiguity for the developer who will submit the code about what is expected of him/her. So, here are some steps that a developer can take before sending the code for review:

Make sure the code is complete: Before submitting the code for review, the developer should make sure that the feature is complete and all necessary changes have been made. It is best to avoid submitting incomplete code for review as it can waste the reviewer’s time.

Test the code locally: The developer should test the code locally to make sure that it is functional and doesn’t contain any major bugs. This can help reduce the number of issues found during the code review process.

Format the code: The developer should format the code in a consistent manner so that it is easier to read and understand. This includes indentations, line breaks, and other formatting conventions.

Write clear comments: The developer should write clear and concise comments in the code to help the reviewer understand the purpose of each section of code. This can help speed up the review process by reducing the need for back-and-forth questions.

Create a pull request: Once the code is complete, the developer should create a pull request in Bitbucket and link it to the relevant Jira ticket. This will help ensure that the reviewer has all the necessary context for the changes made.

To make the code review process easier for the reviewer, the developer can do the following:

Keep the changes small: Instead of submitting a large, complex change, the developer should try to break it down into smaller, more manageable pieces. This can make it easier for the reviewer to understand and assess the changes.

Provide clear descriptions: The developer should provide a clear and detailed description of the changes made and any issues that may arise. This can help the reviewer understand the purpose of the changes and what to look for during the review.

Use clear naming conventions: The developer should use clear and consistent naming conventions for variables, functions, and other elements of the code. This can help the reviewer understand the purpose of each element more quickly.

Respond to comments promptly: If the reviewer finds any issues during the review process, the developer should respond promptly and address the issues as quickly as possible. This can help speed up the review process and ensure that the code is ready for deployment in a timely manner.

By following these steps and best practices, the developer can help ensure that the code review process is as smooth and efficient as possible.

Code Review Step Needs to be Taken by The Reviewer

Lastly, I’m going to imagine a scenario where a piece of code is written and ready to be reviewed.  and the pull request is created for integrate the changes. Then I’m going to describe the steps that can be taken to review the code.

Here is a step-by-step guide on how to do a code review using Git and Jira:

  1. Start by opening the pull request in Jira that contains the changes to be reviewed. Read through the description of the pull request to get a general idea of the changes that have been made.
  2. Clone the repository containing the code that has been changed. Make sure you have the latest version of the code by pulling any changes that have been made to the repository since the pull request was created.
  3. Switch to the branch that contains the changes you want to review. You can do this by running the command git checkout <branch-name> in the terminal.
  4. Build the code locally to make sure it compiles and runs without errors. If there are any issues, report them to the developer who made the changes.
  5. Go through the changes made to the code file by file. Look for any syntax errors, logical issues, performance problems, and any other issues that may be relevant to the functionality of the code. You can use Git to see the exact changes that have been made by running git diff <file> in the terminal.
  6. Leave comments on the pull request in Jira for any issues you find. Be as specific as possible and provide examples of how the code could be improved.
  7. If you find any issues that need to be fixed, request changes on the pull request in Jira. The developer who made the changes will receive a notification and can then make the necessary changes.
  8. Once all the issues have been addressed, review the code again to make sure everything looks good. If you’re satisfied with the changes, you can approve the pull request in Jira.
  9. Merge the changes into the main branch. You can do this by running the command git merge <branch-name> in the terminal.
  10. Finally, delete the branch containing the changes you just reviewed by running the command git branch -d <branch-name> in the terminal.

That’s it! By following these steps, you can perform a thorough code review and ensure that the code meets your standards for quality and functionality.

Summary

Code review is a vital part of the software development process, helping to improve code quality, catch defects early, and ensure that code meets customer requirements. In this comprehensive guide to code review, I explained everything you need to know about code review, including its benefits, types of code review, and best practices for conducting a successful code review.

The guide begins by outlining the benefits of code review, including improved code quality, increased knowledge sharing, and better team collaboration. I then went on to explain the different types of code review, including peer review, tool-assisted review, and formal review, and discusses the pros and cons of each approach.

Next, the guide covers the essential elements of a successful code review process, including setting clear objectives, defining coding standards, and establishing a review process that works for your team. I also provided tips for conducting a constructive code review, such as focusing on specific issues, using a collaborative approach, and being respectful and professional in your feedback.

The guide concludes with some best practices for conducting a successful code review, such as using code review tools, tracking metrics to measure success, and creating a culture of continuous improvement. This guide emphasized the importance of making code review an integral part of your development process, rather than a one-time event, in order to maximize its benefits and improve the overall quality of your code.

In summary, this comprehensive guide to code review provides a thorough overview of the benefits, types, and best practices of code review. It emphasizes the importance of making code review an integral part of the software development process, and provides actionable tips and insights for conducting successful code reviews. By following the guidance in this guide, software development teams can improve the quality of their code, catch defects early, and ensure that their code meets customer requirements.

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Hamid Mosalla

Hi, I'm Hamid Mosalla, I'm a software developer, indie cinema fan and a classical music aficionado. Here I write about my experiences mostly related to web development and .Net.

 

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