Software teams work on the principle of self-organization, and the skill sets of different team members may overlap. This is partly achieved through code review. By doing code reviews, developers become familiar with the code base and learn new technologies and techniques that help develop their skills.
What is a code review, and why is it necessary?
Code review is a systematic review of software source code to find bugs and evaluate quality. Code review consists of the following steps:
- Determining the most efficient ways to complete a task;
- Search for logical errors;
- Search for the most common vulnerabilities;
- Malware detection is a special kind of code review to look for suspicious code snippets or any malware integrated into the software.
When a developer completes a task, another developer analyzes the resulting code, considering the following questions.
- Are there obvious logical errors in the code?
- Is the code entirely usable for all the use cases described in the code requirements?
- Do the new automated tests cover the added code sufficiently? Do existing computerized tests need to be rewritten to accommodate code changes?
- Does the code meet the requirements of the existing design guidelines?
Code reviews should be part of the team’s existing workflow. For example, if it’s customary for a team to create task branches, code reviews should begin after all code has been written, automated tests have been run, and passed, but before the code is merged into the upstream branch. Then the person checking the code will be able to pay attention to those sections of the code that did not fall into the field of view of automation, and errors in the code will not fall into the main development branch.
There are several reasons why code review is considered a necessary part of development.
The first reason is risk reduction. Let’s say you have software written by a freelancer or agency, but you’re not sure about the quality of the work because even good developers can miss something. So double-checking is always a good idea.
What’s more, by working together to learn code, each team member can come up with more innovative solutions that will improve the project’s overall performance.
The main thing to remember about code review is that it should be done before your new development team takes on the codebase or project. A code review before launching a project allows your team to review it and determine the quality of the code and whether improvements are needed.
There are no hard and fast rules about who should conduct the review in a code study. The ideal scenario is when the analysis is carried out by a more experienced colleague, a team leader, or a lead project developer. In reality, this does not always work out: often, the middle checks the middle.
Tasks of the code reviewers
Code review is a stage of code development. Most often, it is carried out by other developers from the same team. This is how more experienced coders control the quality of the work of juniors or interns. A reviewer on individual components can show you how to simplify and clarify the code. For example, he will offer to take a function that has already been written for another fragment. Code review is especially important for large teams.
In large-scale projects, the code is very voluminous, and each developer knows only their fragment. People often don’t know what’s happening in other components and modules. This is not a very stable situation because the code’s author may go on vacation or stop maintaining his fragment for various reasons. The code review stage adds a second person who understands the code and can work with it.
Code reviews are an excellent way to agree within a team on how to write code. For example, obfuscated code is challenging to maintain and scale. The code review stage helps share knowledge, find new solutions, and improve the development process.
Unlike testing, it is more important for a code review to understand the logic of a solution than to find errors. And also – to convey the essence of the problem to the developer. This will require the ability to accurately formulate the situation and report it without unnecessary emotions.
The code reviewer moves from the general to the specific. First, he needs to understand what problem the author of the code was solving. To do this, the inspector looks at the terms of reference and clarifies the details with the developer. Next, you must evaluate the code’s architecture and see if it is written correctly. This is the most valuable stage of the code review; it helps to avoid blunders and saves time for the testing team.
When the reviewer has figured out the problem and the logic of the solution, he looks at the functions, unique algorithms, and their effectiveness. Checks if it is possible to replace them with other methods and if it would be better for the whole product.
After verification, the reviewer leaves comments for the developer. His task at this stage is to explain why it is essential to correct the error. Also, the reviewer can suggest a solution or provide links to materials with which the developer will quickly put the code in order.
To check the code, you need to understand it. It’s good that the reviewer has already solved such problems, written similar code, and was familiar with the technology stack that the team uses. Then the reviewer will be able to give the developer valuable comments.
Code Review Guide
Divide code reviews into time slots
Don’t try to analyze the whole project at once. Experts advise not to look at more than 400 lines of code at once. Moreover, a one-time check should take no more than an hour. Humans cannot efficiently process this information, especially over a long period. When you exceed this mark, the ability to detect errors is noticeably reduced, so you may miss some critical mistakes.
Seek help from teammates
One head it’s good, but two are better. You may be surprised how much the quality of the review will improve if you share this process with someone else. Collaborative code review improves the software and increases the team’s competence level by sharing knowledge through discussion.
Before proceeding with the review, the team should set clear goals, such as “halving the defect rate.” The purpose of “finding more bugs” is too abstract to be achieved. During the review, record metrics such as the speed of the evaluation, the number of bugs found per hour, and the average number of bugs per line of code. Constant monitoring of the review results will show you an accurate picture of internal processes.
Keep a positive attitude.
Code review can sometimes hurt relationships within a team. Nobody likes to be criticized, so it’s essential to maintain a friendly atmosphere unless you want your co-workers to lose motivation. Instead of taking each bug negatively, consider that these are new opportunities to improve the quality of the code.
Remember that feedback must be balanced. Its goal is not to offend a person but to highlight areas for improvement reasonably (for example, using code examples and links to patterns).
Also, don’t focus only on mistakes; praise them if you see an exciting solution or a non-standard approach. So again, show a colleague that you have one goal, and relieve stress.
Seven Reasons Why Reviewing Code Builds Better Skills & Teams
Code review is helpful for any team, no matter what development methodology they follow and helps distribute work among employees. No team member is the only expert on a particular code base. Simply put, code reviews are a tool for sharing knowledge about the code base among all team members.
Code review promotes knowledge sharing.
At the heart of all software, teams are unprecedented freedom of action since all team members can take work from the backlog and perform it. As a result, teams storm new work with great enthusiasm because the tasks are independent of each other. Generalists can work both on the client side and the server side.
During code review, developers come across new ideas and technologies, and as a result, the quality of their code increases.
Thanks to code checks, the accuracy of estimating the complexity of work is improved.
Recall the section on complexity estimation. The whole team is involved in this procedure, and when all participants equally well know the product, it is possible to assess the volume and complexity of the work more accurately. When the need arises to add new features to existing code, its first developer can share their knowledge and assess the complexity. In addition, all code reviewers receive information about the difficulties, known issues, and features associated with the code base fragment of interest. Therefore, the reviewer has the same knowledge of this code as the original developer. This gives the team a wealth of evidence-based input to make a more accurate and reliable final estimate of complexity.
Code review allows you to take breaks at work.
No one wants to be the only person who can answer all questions about a piece of code. Also, no one is tempted to deal with a critical part of code someone else wrote, especially during an emergency in the production environment. Code reviews promote knowledge sharing across the team, so anyone can pick up the baton and move on. But the main benefit lies elsewhere: if more than one developer is involved in critical tasks, all participants in the process can take breaks from work. If you feel you’re being held hostage by source control, checking your code is a great way to find freedom. So you can go on a long-awaited vacation or devote time to another product component.
Code reviews enable the training of new specialists.
Another distinguishing feature is that when new members join the team, more experienced people become mentors. During code reviews, they discuss the code base. Often, knowledge is hidden in the code and unknown to the team. During the check, they are found. Beginners bring their fresh eyes and notice ugly, overlooked, due to lack of time fragments of the code base that need to be revisited. As you can see, through code review, new helpful information is framed by existing knowledge.
At the same time, code review should not be reduced to the supervision of junior employees by senior employees. Any member of the team can check the code of any other member. Knowledge should have no boundaries! Yes, code review can be helpful for beginners, but it should not be used only as a mentoring tool.
Distributing the load
When the author is going to appoint reviewers, he chooses from a wide range of team members. Any two specialists can check the code. Thanks to this, the process is decentralized, all work does not depend on one person, and the team has a wide selection of specialists who can participate in code review.
Checking before merge
Mandatory review of the code before it is merged into the upstream branch ensures that unverified code does not enter the production environment. This means that controversial architectural decisions made at 2:00 a.m. and mistakes that an intern makes in using a design pattern will be caught before they can have long-term (and unfortunate) consequences for the application.
Use social pressure to your advantage.
When developers know that a teammate will review their code, they put in extra effort to make sure the code passes all tests and is written as well as possible so that the reviewer does not run into difficulties. With this awareness, the process of writing code becomes more streamlined and, as a result, runs faster.
Don’t wait for code review if an outsider’s perspective is needed early in the development cycle. Early feedback followed by frequent comments improves the quality of the code, so feel free to ask for help at any point in time. This will not only enhance your results but also develop peer review skills.
Code review should be an essential process in any development company as it helps to maintain high-quality coding standards. Working together on a code review brings the team together and provides an opportunity to share knowledge and experience within the company. So if you’re starting a startup or outsourcing a project to another team, always do code reviews to ensure your software is of the best quality.