Namespaces: I'm not sure what this is currently. I would expect classes within a namespace to show up, but they don't. Using Parsoid-JS as an example many of the namespace pages are empty with no way to discover the relevant classes it contains.

The namespaces section includes things tagged with @namespace. Each namespace page now contains a list of classes within the namespace. In the sidebar, all classes are listed under Classes, regardless of their namespace membership.

Only the last part is shown, no sub menus or full names.

The useLongnameInNav config option (documented on the wiki page) displays the full name in the sidebar. I agree that this is really helpful to have.

The menu is missing hierarchy.

The simple way to do this would be to indicate hierarchy by indenting items under other items, similar to what JSDuck does. However, because of the font size, spacing, and width of the sidebar, the sidebar can't visually support more than one maybe two levels of indentation without having a lot of horizontal scroll. Adding indentation would probably be fine for most small codebases, but in MediaWiki core, we have up to 5 levels of hierarchy.

For now, we've opted to indicate hierarchy by:

• using full names in the sidebar via the useLongnameInNav config option
• using the lists of classes on namespace and modules pages and lists of subclasses on class pages
• providing an option to add a custom landing page to any of the main site sections to manually provide extra context and hierarchy information when not adequately indicated by the two methods above

In the future, I can see two options for improving this:

1. Add an option to enable indentation, so smaller codebases can enable it
2. Redesign the sidebar to be more dense and support several levels of indentation

Let me know what you think! Since the initial improvements have been complete, I'm removing myself as the assignee and moving this to needs discussion.