Yes, this particular UX is poor. It's not intuitive that clicking the filename has different behavior from clicking elsewhere in the file's row. Expanding the row inline needs a leading widget.

This particular issue is solved in GitHub proper, and derives from the Windows 95 tree view widget [1], which I seem to remember from Windows 3.x but can't find a screenshot.

The hover behavior is just not an intuitive or accessible default. I can't imagine someone being able to use this if they have a hard time clicking without moving the mouse. It also wastes resources fetching file/directory contents while the user is moving the cursor to a predetermined file they presumably wish to open.

[1]: https://learn.microsoft.com/en-us/windows/win32/winauto/syst...

thank you both for the feedback, i'm revisiting it now and i do see what the both of you are illustrating.

i think i will get rid of the change on hover, it is a distraction and perhaps was just my ambition to show people how fast we load.

edit: fixed

If you click the file row (not the filename as that will navigate to file page), then hovering over other files won't change the preview.