"Collapse all" button in sidebar doesn't collapse trash folder

[laurent22]

[MorbidMiyako]

I'm looking into this issue, since it doesnt seem to be on the Kanban board yet I hope it's possible to pick up this issue.

[MorbidMiyako]

After having investigated this issue, the issue seems to stem from folder.children.length being 0 for the Trash folder.

1. A simple workaround would be to simply add the trash folder to 'canBeCollapsedIds' manually given that it's not added yet.
   Although this does not pose any problems visually, it would mean that it could be in a 'open' state, if all other folders are then closed the 'toggleAllFolders' would on first click visually not do anything (and behind the scenes collapse the Trash folder). Resulting in needing a second call of 'toggleAllFolders' to achieve the desired effect of opening all the folders again.
2. A more complex solution would be to determine whether there are children in the Trash folder, and hence if it is collapsible.
   This might be implementable by checking whether the trash folder has the icon indicating it can be folded open. However it seems that a current difficulty is to determine the number of children in the Trash folder. Although the issue would be fixed, it would still leave the issue of determining the number of children in the trash folder.

Please let me know if there is a preferred approach to solving this issue @laurent22

For now I will aim to solve the issue by determining whether the Trash folder contains children in order to implement option 2.

[MorbidMiyako]

I've resolved the issue by determining whether there are deleted items using the store, I will be providing a pull request soon.