Discourse sidebar’s “Show more” button never collapses

Clicking “Show more” should expand a sidebar folder and replace the control with “Show less.” On macOS app version 26.917.71314, the additional chats appear, but the original button remains unchanged. That points to a sidebar state problem rather than a failure to load the folder contents.

What should happen when “Show more” is clicked?

The control needs to represent both sides of the interaction. In its initial state, it says “Show more” because some folder chats are hidden. After activation, it should say “Show less”, and clicking it again should hide the extra chats while restoring the original label.
Removing the control entirely could also solve the wasted-space problem, but only if another collapse control is available. Otherwise, the user can expand the folder but cannot reverse the action from that button. Changing the label to “Show less” is the clearer behavior.
The reported build appears to update the visible chat list without updating the button accordingly. That makes this look like a state-and-label synchronization issue, although the report does not provide enough implementation evidence to identify the exact faulty component.

How to reproduce the sidebar issue

The affected environment is the Discourse desktop app on macOS, version 26.917.71314.

1. Open a folder in the sidebar that contains enough chats for the “Show more” control to appear.
2. Activate “Show more.”
3. Confirm that the folder now displays its additional chats.
4. Observe that the sidebar still shows “Show more” rather than changing it to “Show less.”

The report says this happens consistently, so the behavior is not an intermittent rendering glitch. A reliable fix therefore needs to handle every transition between the collapsed and expanded states, not merely the first expansion.
For verification, the expected sequence is:

• Folder collapsed, with “Show more” visible
• Folder expanded, with “Show less” visible
• Folder collapsed again after “Show less” is activated
• Original “Show more” label restored

The button copy and folder contents must never disagree about the current state.

Which implementation detail needs fixing?

The control should derive both its visible label and its expanded status from the same sidebar state. Updating only the list of visible chats leaves the interface partially interactive: the content changes, but the control still claims there is more to reveal.
An accessible implementation should expose the same condition through aria-expanded, changing it when the folder is opened or closed. The click handler should update that state together with the chat list and button label. Re-rendering the folder from that state can also prevent the control from reverting to stale text.
Hiding the button without introducing a collapse action would be an incomplete fix. It would remove the visible dead space, but it would also remove the user’s obvious way to undo the expansion. The preferred result is a reversible control whose text always describes what the next click will do.

What should be checked before closing the bug?

The fix should be exercised with both mouse and keyboard activation. Each activation needs to produce the correct folder contents, button text, and expanded accessibility state. The label should also remain correct after the sidebar refreshes or the user moves to another folder and returns.
The key acceptance condition is simple: the folder’s visibility and the “Show more” or “Show less” label must change together. If they can still get out of sync, the underlying state transition remains broken.