When viewing a file in a repo, be able to fold/collapse sections of code (functions/methods/blocks)
Problem to solve
As a developer who's browsing a large or unfamiliar source code file, it can be difficult to get an overview of the structure of the file. Many code editors (e.g. Visual Studio Code) offer the ability to "fold" or "collapse" sections of the source code by clicking on a chevron/arrow in the gutter, which temporarily hides the contents of the section next to the arrow. ("Section" here could mean a function/method, or a block within a function, an entire class definition, or another language-specific range of lines.)
It would be nice if GitLab offered a similar feature when viewing source code files (blob pages) in a repo.
Intended users
User experience goal
Improve navigation within a single source code file.
Proposal
Make use of existing GitLab source code analysis infrastructure (Rouge? GKG? Zoekt?) to figure out the structure of a source code file. Use that to populate a frontend for collapsing sections.
Example of a Ruby source file viewed in Visual Studio Code:
Permissions and Security
No permission/security changes; this would only show existing information.
What is the competitive advantage or differentiation for this feature?
GitHub already provides this feature. Example of a Java source file viewed on GitHub:
