How to make great code reviews? 🤝
Today at @doctolib we had a very interesting workshop about code reviews: why they matter, how to ensure they are done well and how they serve both the team and the product quality.
I thought it would be interesting to share what I learned! 🤓
What is a code review?
Once you've finished working on a feature, you can push your work on your branch and make a pull request. Another developer will then look over your code and consider if your work can be merged to master (or another branch you specify).
What are the goals of a code review?
- ✨ Improve code quality and coding standards
- 🕷 Find bugs as early as possible: the sooner, the better
- 🎓 Share knowledge and learn from others: regardless of your level of seniority, you can learn a lot!
An example of a good code review workflow
1 - 🛎 Know there is a pull request waiting for you
- Set notifications on GitHub / GitLab
- Check your project management board (Jira, Trello, Asana...)
💻 As PR creator :
- Tag reviewers on Github to make sure they are notified
- Or ping them directly on slack or whatever tool you use
2 - ⏳ Take time: schedule the code review
- Set a dedicated time to focus when you are assigned a PR to review
- Or you can even have recurring dedicated times in your calendar
💻 As PR creator :
- Don't hesitate to suggest a slot to the reviewer so you can go through the code together
3 - 💡 Get to know the task
- Check the user story or bug report: to fully understand the context and the expected behavior of a feature or fix
- Ask someone who knows: the developer who coded it or the product owner in charge
- Read the tests: they can also be a good way to understand the expected behavior
💻 As PR creator :
- Don't hesitate to add screenshots / gifs of the feature so that it will be easier for the reviewer to understand what's going on
4 - 🕷 Find bugs: what to look for?
- Make sure the whole story is covered: check if the tests and implementation cover the edge cases you can think of
- Performance issues: look at performance to make sure there is nothing slowing down
- Conventions: make sure the naming, syntax, etc... respect the standards defined
- Code quality/clarity: check if the code is easily readable and understandable and whether it could be refactored
- UI design: make sure the changes respect the wireframes and user experience
- Security: verify you don't see a security breach introduced by the PR
💻 As PR creator :
- It's your responsibility to test as much as you can and ask for the PR only when it seems in order to you
5 - 🤝 Give feedback
- It's harder to communicate in writing: remember that text can easily be misinterpreted so don't hesitate to emphasize what's good and choose your words wisely
- Ask open questions: to make sure you understand the code and decisions
- Have empathy: make sure you're making suggestions in a positive way and there is no frustration if things need to be modified
- Focus first on what matters the most: don't spend too much time discussing minor syntax errors if you also spot serious bugs or security breaches
- Request changes if necessary
💻 As PR creator :
- Remember it's your code that is criticized... not you!
6 - 🎉 Approve the pull request!
When should you approve a pull request?
- when the feature does what it is supposed to do
- when you feel comfortable maintaining the code
- when you feel comfortable debugging the code
This great workshop was made by Emmanuel Gautier, thanks! 👏
If you have other good practices, tips or tools for code reviews, I'd love to hear about them! 🙌