gitlab-ce/doc/development/fe_guide/tips_and_tricks.md

stage	group	info	title
none	unassigned	Any user with at least the Maintainer role can merge updates to this content. For details, see https://docs.gitlab.com/ee/development/development_processes.html#development-guidelines-review.	Tips and tricks

Code deletion checklist

When your merge request deletes code, it's important to also delete all related code that is no longer used. When deleting Haml and Vue code, check whether it contains the following types of code that is unused:

• CSS.

  For example, we've deleted a Vue component that contained the .mr-card class, which is now unused. The .mr-card CSS rule set should then be deleted from merge_requests.scss.

• Ruby variables.

  Deleting unused Ruby variables is important so we don't continue instantiating them with potentially expensive code.

  For example, we've deleted a Haml template that used the @total_count Ruby variable. The @total_count variable was no longer used in the remaining templates for the page. The instantiation of @total_count in issues_controller.rb should then be deleted so that we don't make unnecessary database calls to calculate the count of issues.

• Ruby methods.