Code Review

A guide for reviewing code and having your code reviewed.

###Everyone

• Accept that many programming decisions are opinions. Discuss tradeoffs, which you prefer, and reach a resolution quickly.
• Ask questions; don't make demands. ("What do you think about naming this user_id?")
• Ask for clarification. ("I didn't understand. Can you clarify?")
• Avoid selective ownership of code. ("mine", "not mine", "yours")
• Avoid using terms that could be seen as referring to personal traits. ("dumb", "stupid"). Assume everyone is attractive, intelligent, and well-meaning.
• Be explicit. Remember people don't always understand your intentions online.
• Be humble. ("I'm not sure - let's look it up.")
• Don't use hyperbole. ("always", "never", "endlessly", "nothing")
• Don't use sarcasm.
• Keep it real.
• Talk in person if there are too many "I didn't understand" or "Alternative solution:" comments. Post a follow-up comment summarizing offline discussion.

Reviewing Code

Understand why the code is necessary (bug, user experience, refactoring). Then:

• Communicate which ideas you feel strongly about and those you don't.
• Identify ways to simplify the code while still solving the problem.
• If discussions turn too philosophical or academic, move the discussion offline to a regular Friday afternoon technique discussion. In the meantime, let the author make the final decision on alternative implementations.
• Offer alternative implementations, but assume the author already considered them. ("What do you think about using a custom validator here?")
• Seek to understand the author's perspective.
• Sign off on the pull request with a 👍 or "Ready to merge" comment.

Having Your Code Reviewed

• Be grateful for the reviewer's suggestions. ("Good call. I'll make that change.")
• Don't take it personally. The review is of the code, not you.
• Explain why the code exists. ("It's like that because of these reasons. Would it be more clear if I rename this class/file/method/variable?")
• Seek to understand the reviewer's perspective.
• Try to respond to every comment.
• Wait for the Scrum Master to merge your Pull Request.