In Caps, the 'undo' and 'redo' buttons in the sidebar don't seem to do anything when they're clicked. This is consistent in any web browser I've tested with (Chrome, Safari and Firefox on macOS 13.0, as well as Chrome and Edge on Windows 11). Using undo/redo via keyboard shortcuts behaves as expected.
Adding the following JS code would fix this:
bind('#button-undo', 'click', undo); bind('#button-redo', 'click', redo);