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Code review

Code review is a vital for effective and efficient collaboration of successful teams.


  • Promote shared understanding of the codebase. Getting other people to look at code changes improves visibility and understanding of the way in which code works. It therefore helps protect against the loss of knowledge and productivity that can occur as developers come and go.
  • Provide a different perspective on solutions. Coming with a fresh perspective and different experiences, the reviewer of code may think of possibilities that did not occur to the original developer.
  • Improved code quality. The reviewer may notice issues with scalability, typos or other issues that might have slipped by the developer, but which may not cause errors or warnings visible to the end user.

Questions to ask when reviewing code

  • Is there enough commenting (or too much)?
  • Is the code readable? Are the names of variables, functions, methods and classes clear and unambiguous?
  • Are functions and class methods broken down to each fulfill one discrete requirement?
  • Have unit tests been written?
  • Has documentation been written/updated? Do comments in the code point to it and vice versa?
  • Is an upgrade script needed? If so, does it run to completion and without an error?
  • Are assumptions being made about the way the site will be used that might not
    be valid? For example, hard-coding http:// or https:// in URLs instead of check what protocol was used for the request and/or making the URL ambivalent (start with //).
  • Is code secure or does it avoid creating new vulnerabilities implementations for an existing functionality?

Preparing code for code review

  • Provide clear description about what, why and how the code has been changed.
  • Provide screenshots, if applicable.
  • Read your own code changes and add comments to parts that may raise questions.
  • Provide a link to the issue tracker.
  • Assign relevant developers to review the pull request.
  • Assign yourself as an owner of the pull request.
  • Add Needs review label to the pull request.

Read more about Mindful Communication in Code Reviews.


Using labels on GitHub can help organise pull requests and issues. Here are the labels that describe the most of the states of pull request.

Pull Request labels

An example of the pull request progression through labels:

DO NOT REVIEW -> Needs review -> Ready for test -> Ready to be merged

Github Labels script can automatically create above labels in your projects.