Code Review Tools For Developers
Code review is a part of the software development process that involves checking the source code to identify errors at an early stage. A code review process is typically carried out before merging with the codebase.
An effective code review prevents errors and bugs from creeping into the project, improving code quality early in the software development process.
In this post, we will explain what code review is and explore popular code review tools that help organizations with the code review process.
What is the code review process?
The main objective of the code review process is to evaluate any new code for errors, failures, and quality standards set by the organization. The code review process should not consist of just one-sided feedback. Therefore, an intangible benefit of the code review process is the improvement of the coding skills of the collective team.
If you want to start a code review process in your organization, you must first decide who will review the code. If you are on a small team, you can assign team leaders to review the entire code. In a larger team with multiple reviewers, you could enable a process where each code review is assigned to an experienced developer based on their workload.
The next consideration is to decide on the deadlines, rounds, and minimum requirements for submitting code review requests.
The final consideration is on how feedback should be given in the code review process. Make sure to highlight the positive aspects of the code while suggesting alternatives for the disadvantages.
Your feedback should be constructive enough to encourage the developer to understand your perspective and start a conversation when necessary.
It’s easy for code reviews to get stuck in limbo, leading to being less efficient and even counterproductive.
Why is code review critical?
The code review process is critical because it is never part of the formal curriculum in schools. You can learn the nuances of a programming language and project management, but code review is a process that evolves as an organization progresses.
Code review is critical for the following reasons:
- Make sure you don’t have errors in your code.
- Minimize your chances of getting into trouble.
- Confirm that the new code adheres to the guidelines.
- Increase the efficiency of the new code.
Code reviews lead to an improved experience for other team members. Since a senior developer often performs a code review, a junior developer can use this information to improve their own coding.
How is a code review performed?
There are four ways to conduct code reviews.
Over-the-shoulder code reviews
Code reviews take place at the developer’s workstation, where an experienced team member reviews the new code, providing suggestions through conversation. It is the easiest approach to code reviews and does not require a predefined structure.
This code review can still be done informally today, along with a formal code review process that may be in place. Over-the-shoulder code reviews have traditionally been done in person, while distributed teams can follow this approach also through collaboration tools.
While over-the-shoulder code reviews are a great way to review new code, geographically distributed teams have traditionally relied on email for code reviews.
In this code review process, a developer emails a series of changes to the entire development team, typically through version control systems that automate notifications. This email starts a conversation about the changes, where team members can request more changes, point out bugs, or ask for clarification.
In the early days, email was the primary means of communication due to its versatility. Open source organizations used to maintain a public mailing list, which also served as a means of discussing and giving feedback on the code.
With the advent of code review tools, these mailing lists continue to exist, but primarily for subsequent releases and discussions.
Pair programming is an ongoing process of code review. Two developers sit at a workstation, but only one of them is actively coding while the other provides information in real-time.
While it can serve as a great tool for inspecting new code and training developers, it could potentially prove inefficient due to its time-consuming nature. This process prevents the reviewer from doing any other productive work during the period.
With the help of tools
A tool-assisted code review process involves the use of a specialized tool to facilitate the code review process. A tool generally helps you with the following tasks:
- Organize and display the updated files in a change.
- Facilitate a conversation between reviewers and developers.
- Evaluate the effectiveness of the code review process with metrics.
Although these are the general requirements of a code analysis mechanism, modern methods can provide a handful of other functions. We’ll explore a range of code review tools later in this post.
Why should you use the code review tools?
The main result of a code review process is to increase efficiency. Although these traditional code review methods have worked in the past, you may be losing efficiency if you have not switched to a code review tool. A code review tool automates the code review process so that a reviewer focuses solely on the code.
A code review tool integrates with your development cycle to initiate a code review before new code is merged into the main codebase. You can choose a tool that is compatible with your technology stack to integrate seamlessly into your workflow.
For example, if you use Git for code management, TravisCI for continuous integration, make sure you select a tool that supports these technologies to fit into the development process.
There are two types of code testing in software development: dynamic and static.
Dynamic analysis involves checking if your code follows a set of rules and running unit tests, typically performed by a predefined script. Static code testing is done after a developer creates a new code that is merged with the current code.
Now let’s dive into some of the most popular code review tools!
Analysis of 12 powerful code review tools
In this article, we review the most popular static code review tools.
1. Review Board
The Python programming language and its installers, MySQL or PostgreSQL as the database, and a web server are the prerequisites for running Review Board on a server.
You can integrate the Review Board with a wide range of version control systems: Git, Mercurial, CVS, Subversion, and Perforce. You can also link the Review Board to Amazon S3 to store screenshots directly in the tool.
Review Board allows you to conduct code reviews before and after authorization, depending on your needs. If you have not integrated a version control system, you can use a diff file to upload code changes to the tool for review.
A graphical comparison of your code changes is also provided. In addition to code reviews, Review Board allows you to perform document reviews as well.
The first version of the Review Board came out more than a decade ago, but it is still in active development. So the Review Board community has grown over the years and you are likely to find support if you have any issues using the tool.
The Review Board is a simple code review tool, which you can host on your server. You should give it a try if you don’t want to host your code on a public website.
Crucible is a collaborative code review tool from Atlassian. It is a set of commercial tools that allows you to review the code, discuss changes in plans and identify errors in a series of version control systems.
Crucible offers two payment plans, one for small teams and one for businesses. For a small team, a one-time payment of $ 10 is required for unlimited deposits limited to five users. For large teams, fees start at $ 1,100 for ten unlimited users and repositories.
Both plans offer a 30-day free trial without the need for a credit card.
Similar to the Review Board, Crucible supports a large number of version control systems: SVN, Git, Mercurial, CVS, and Perforce. Its main function is to allow you to perform code reviews. In addition to general code comments, it allows you to comment online within the differences view to pinpoint exactly what you specifically mean.
Crucible integrates well with other Atlassian business products such as Confluence and Enterprise BitBucket. However, you may get the most benefits from Crucible when used in conjunction with Jira, Atlassian’s Issue, and Project Tracker. It allows you to perform pre-commit reviews and audits on the merged code.
If you use GitHub to maintain your Git repositories in the cloud, you may have already used forks and code review requests. In case you have no idea what GitHub is, here is a beginner’s guide to GitHub and the differences between Git and GitHub.
GitHub has a code review tool built into its pull requests. The code review tool is included in the main GitHub service, which provides a free plan for developers. GitHub’s free plan limits the number of users to three in private repositories. Payment plans start at $ 7 a month.
GitHub allows a reviewer with access to the tag repository to map to the pull request and complete a review. A developer who has submitted the pull request can also request a review from an administrator.
In addition to the general pull request discussion, you can analyze the spread, comment online, and check the change history. The code review tool also allows you to resolve simple Git conflicts through the web interface. GitHub even allows you to integrate with additional review tools throughout its marketplace to create a more robust process.
GitHub’s code review tool is a great tool if you’re already on the platform. It does not require any additional installation or configuration. The main problem with the GitHub code review tool is that it only supports Git repositories hosted on GitHub. If you’re looking for a similar code review tool that you can download and host on your server, you can try GitLab.
Phabricator is a list of open-source tools from Phacility that help you review your code. While you can download and install the code review toolkit on your server, the Facility also provides a cloud version of Phabricator.
You have no limitations if you install it on your server. However, you will be charged $ 20 per user per month (capped at $ 1000 / month maximum), which includes support. To give it a try, you can opt for a 30-day free trial.
Phabricator supports the three most popular version control systems: Git, Mercurial, and SVN. You can manage local repositories as well as keep track of externally hosted repositories. You can also scale it to multiple servers.
Beyond a traditional code review tool
Phabricator provides a detailed platform to have a conversation with your team members. You can do a pre-review of a new team member or do a review of the newly submitted code. You can also perform a merged code review, a process Phabricator calls “auditing.” Here is a comparison between a review and an audit in Phabricator.
Phabricator’s additional tools help you through the software development cycle. For example, it provides you with a built-in tracker to manage bugs and features. You can also create a wiki for your software within the tool through Friction. To integrate the tool with the unit tests, you can use the Phabricator CLI tool. You can also build applications on top of Phabricator through its API.
In short, Phabricator provides you with a ton of features that help you streamline your development process. It makes perfect sense to opt for this tool if your project is at an early stage. If you don’t have the experience to configure it on your server, you should opt for the hosted version of the tool.
SmartBear Collaborator is a code and document review tool for development teams. In addition to source code review, Collaborator allows teams to review design documents as well. A 5-user license package is priced at $ 535 per year. A free trial is available depending on your business requirements.
Collaborator supports a large number of version control systems such as Subversion, Git, CVS, Mercurial, Perforce, and TFS. It does a good job of integrating with popular project management tools and IDEs like Jira, Eclipse, and Visual Studio.
This tool also enables reporting and analysis of key metrics related to your code review process. Also, Collaborator helps in managing the audit and tracking of errors as well. If your technology stack includes business software and you need support setting up your code review process, you should give Collaborator a try.
CodeScene is a code review tool that goes beyond traditional static code analysis. It performs code behaviour analysis including a time dimension to analyze the evolution of its codebase. CodeScene is available in two forms: a cloud-based solution and an on-premises solution.
Cloud-based CodeScene plans start free for public repositories hosted on GitHub. For up to ten private repositories and a ten-member team, CodeScene costs 99 euros (about $ 115) per month. An on-site installation of CodeScene costs 15 euros (about $ 17) per developer per month.
CodeScene processes your version control history to provide visualizations of your code. In addition, it applies machine learning algorithms to identify social patterns and hidden risks in the code.
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Through version control history, CodeScene profiles each team member to chart their knowledge base and create dependencies between teams. It also introduces the concept of hot spots to its repository, identifying the files that experience the most development activity. These hotspots require the most attention in the future.
If you’re looking for a tool that goes beyond a traditional conversational code review tool, be sure to check out the CodeScene free trial. To learn more about the underlying logic behind CodeScene code-behaviour analysis, check out this folio on CodeScene Roles and Use Cases.
Visual Expert is an enterprise code review solution specialized in database code. It is supported for only three platforms: PowerBuilder, SQL Server, and Oracle PL / SQL. If you are using any other DBMS, you will not be able to integrate Visual Expert for code review.
A free trial is available, but you need to submit a request to get a price quote.
In addition to a traditional code review, Visual Expert analyzes each change in your code to anticipate any performance issues due to the changes. The tool can automatically generate complete documentation of your application from the code as well.
If you are using PowerBuilder, SQL Server, or Oracle PL / SQL and want a specialized code review tool for your needs, you should give Visual Expert a try (here is a guide to building efficient WordPress queries ).
Gerrit is a web-based free and open-source review tool for Git repositories, written in Java. To run Gerrit, you need to download the source code and run it in Java. Here is the process of installing a standalone version of Gerrit.
Gerrit combines the functionality of a bug tracker and a review tool in one. During a review, the changes are displayed side by side in a unified diff, with the ability to start a conversation for each line of code added. This tool works as an intermediate step between a developer and the central repository. Furthermore, Gerrit also incorporates a voting system.
If you have the technical expertise to install and configure Gerrit, and you are looking for an open-source review tool, it should serve as an ideal solution for your projects.
Rhodecode is a web-based tool that helps you perform code reviews. It supports three version control systems: Mercurial, Git, and Subversion. A cloud-based version of Rhodecode starts at $ 8 per user per month, while an on-premises solution costs $ 75 per user per year. Although this is business software, its community edition, which is free and open-source, is free to download and compile.
Shooting code enables a team to collaborate effectively through iterative and conversational reviews of the code to improve the quality of the code. This tool also provides a layer of permission management for secure development.
Additionally, a visual changelog helps you navigate the history of your project through various branches. An online code editor is also provided for small changes via the web interface.
Rhodecode integrates seamlessly with your existing projects, making it a great choice for someone looking for a web-based code review tool. Therefore, the community edition is ideal for those with technical experience who are looking for a free and reliable code review tool.
Veracode provides a set of code review tools that allow you to automate testing, speed up development, integrate a proofing process, and improve the efficiency of your project. The Veracode suite of code review tools is marketed as a security solution that looks for vulnerabilities in your systems. They provide a set of two code review tools:
- Static Analysis: A tool that allows developers to identify and correct security flaws in their code.
- Software composition analysis: A tool that manages the process of remediation and mitigation of flaws in the code.
Reviewable is a code review tool for GitHub pull requests. It’s free for open-source repositories, with plans for private repositories starting at $ 39 per month for ten users. Since the tool is integrated with GitHub, you can log in with your GitHub account and get started.
If you want to see a typical review on Reviewable, you can go to a demo review.
One cool thing about Reviewable is that it overcomes some drawbacks of code review in the GitHub pull requests feature. For example, a comment on a line of code is automatically hidden by GitHub once a developer changes the line because GitHub assumes that the problem has been fixed. But in reality, things may be different.
Also, GitHub has relatively small line limits to show file differences.
If you are looking for a tool that is consistent with GitHub, but you want more features than pull requests, Reviewable should be your tool for the job.
If you are using Subversion, the Peer Review for Trac plugin provides a free, open-source option for conducting code reviews on your projects. The Peer Review Plugin is integrated into the open-source project Trac, which is a wiki and issue tracking system for development projects.
Trac integrates the wiki and issue tracker with its reviews to provide a comprehensive solution. While basic exchange and conversation comparison functionality are available, the plugin lets you design custom workflows for your projects.
For example, you could decide what tasks to perform in triggers, such as submitting a change or approval in a code review. You can also create custom reports on your projects.
If you are also looking for a wiki for documentation and an issue tracker to manage your project roadmap, Trac should be a good choice for you.
The code review process plays a key role when it comes to increasing the efficiency of your organization. Specifically, leveraging the correct code review tool is what helps you eliminate redundancy in your development cycle.
We took a closer look at the most popular code review tools available in 2021 and this is what we found:
- For a small team just starting out, the Review Board is a good option to start the code review process.
- If you’re looking for an open-source review tool, try Gerrit, Peer Review for Trac, or the Rhodocode Community Edition.
- Looking for a fairly easy-to-use and supported code review tool? You should try Rhodecode.
- If you use Git and GitHub to manage your codebase, try GitHub’s built-in code review editor. If you want to go beyond the basic features of pull requests, you should take a look at Reviewable.
- Are you on a team that uses Oracle, SQL Server, or PowerBuilder to manage your database code? You can try Visual Expert, a code review tool that specializes in database code.
- If you’re looking for an enterprise solution, try the Atlassian Crucible, the SmartBear Contributor, or, Veracode.
- In case you want to use ML and AI to go beyond code review into behaviour analysis, you should check out CodeScene.
- If you want a complete solution for your software development cycle, take a look at Phabricator’s suite of tools for code review and beyond.
Now it’s your turn – which code review tool are you using? Why? Let us know in the comments!