gitlab-org--gitlab-foss/doc/development/code_review.md
Kamil Trzciński 0f90fd639c Merge branch 'fix/rename-mwbs-to-merge-when-pipeline-succeeds' into 'master'
Rename MWBS service to Merge When Pipeline Succeeds

## What does this MR do?

This MR renames Merge When Build Succeeds feature to Merge When Pipeline Succeeds, because we recently changed the behavior, see https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6675.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] All builds are passing

## What are the relevant issue numbers?

Closes #23354

See merge request !7135
2016-12-05 11:07:57 +00:00

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5.5 KiB
Markdown

# Code Review Guidelines
This guide contains advice and best practices for performing code review, and
having your code reviewed.
All merge requests for GitLab CE and EE, whether written by a GitLab team member
or a volunteer contributor, must go through a code review process to ensure the
code is effective, understandable, and maintainable.
Any developer can, and is encouraged to, perform code review on merge requests
of colleagues and contributors. However, the final decision to accept a merge
request is up to one of our merge request "endbosses", denoted on the
[team page](https://about.gitlab.com/team).
## 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")
- Be careful about the use of sarcasm. Everything we do is public; what seems
like good-natured ribbing to you and a long-time colleague might come off as
mean and unwelcoming to a person new to the project.
- Consider one-on-one chats or video calls if there are too many "I didn't
understand" or "Alternative solution:" comments. Post a follow-up comment
summarizing one-on-one discussion.
## Having your code reviewed
Please keep in mind that code review is a process that can take multiple
iterations, and reviewers may spot things later that they may not have seen the
first time.
- The first reviewer of your code is _you_. Before you perform that first push
of your shiny new branch, read through the entire diff. Does it make sense?
Did you include something unrelated to the overall purpose of the changes? Did
you forget to remove any debugging code?
- 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 of 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?")
- Extract unrelated changes and refactorings into future merge requests/issues.
- Seek to understand the reviewer's perspective.
- Try to respond to every comment.
- Push commits based on earlier rounds of feedback as isolated commits to the
branch. Do not squash until the branch is ready to merge. Reviewers should be
able to read individual updates based on their earlier feedback.
## Reviewing code
Understand why the change is necessary (fixes a bug, improves the user
experience, refactors the existing code). Then:
- Try to be thorough in your reviews to reduce the number of iterations.
- Communicate which ideas you feel strongly about and those you don't.
- Identify ways to simplify the code while still solving the problem.
- 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.
- If you don't understand a piece of code, _say so_. There's a good chance
someone else would be confused by it as well.
- After a round of line notes, it can be helpful to post a summary note such as
"LGTM :thumbsup:", or "Just a couple things to address."
- Avoid accepting a merge request before the build succeeds. Of course, "Merge
When Pipeline Succeeds" (MWPS) is fine.
- If you set the MR to "Merge When Pipeline Succeeds", you should take over
subsequent revisions for anything that would be spotted after that.
## The right balance
One of the most difficult things during code review is finding the right
balance in how deep the reviewer can interfere with the code created by a
reviewee.
- Learning how to find the right balance takes time; that is why we have
minibosses that become merge request endbosses after some time spent on
reviewing merge requests.
- Finding bugs and improving code style is important, but thinking about good
design is important as well. Building abstractions and good design is what
makes it possible to hide complexity and makes future changes easier.
- Asking the reviewee to change the design sometimes means the complete rewrite
of the contributed code. It's usually a good idea to ask another merge
request endboss before doing it, but have the courage to do it when you
believe it is important.
- There is a difference in doing things right and doing things right now.
Ideally, we should do the former, but in the real world we need the latter as
well. A good example is a security fix which should be released as soon as
possible. Asking the reviewee to do the major refactoring in the merge
request that is an urgent fix should be avoided.
- Doing things well today is usually better than doing something perfectly
tomorrow. Shipping a kludge today is usually worse than doing something well
tomorrow. When you are not able to find the right balance, ask other people
about their opinion.
## Credits
Largely based on the [thoughtbot code review guide].
[thoughtbot code review guide]: https://github.com/thoughtbot/guides/tree/master/code-review
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