It is frustrating to work in the browser based diff viewer (while reviewing pull requests) because the expand/collapse arrows next to the folders in the file tree have a tiny hitbox. Please make the arrows clickable for the full height of the row and a similar width.

OH! I just discovered that I can expand/collapse by clicking the folder too! That makes it usable! But I would still consider the change for users who intuitively assume the arrows are what need to be clicked.