# Objective

Ensure that, when users undo project panel operations, we don't trash
files with unsaved edits as that could lead to data loss, as outlined
[here](https://github.com/zed-industries/zed/issues/62243#issuecomment-5203625087).

Closes #62243

## Solution

Update `UndoManager::trash` to require confirmation before moving files
to the trash. For files with unsaved edits, users can save, discard, or
cancel the operation while clean files receive a standard trash
confirmation, same as shown when trashing a file through the Project
Panel.

This helps avoid the issue where, if an user undoes a file creation for
a file that has unsaved edits and then quits Zed, the edits that were
saved in memory, as well as the Project Panel history, will now be gone
and there's no way to recover the data.

Batch operations have also been updated to now show a single
confirmation before making filesystem changes, preventing partial
execution when cancelled and warning about unsaved edits.

Lastly, the trash/delete prompt building has been refactored in order
for the Project Panel and Undo Manager to share the same wording,
file-list truncation, and unsaved-change warnings.

## Testing

Tested both manually as well as added the following tests:

*  `project_panel::tests::undo::undo_create_cancel_trash`
*  `project_panel::tests::undo::undo_create_dirty_file`
*  `project_panel::tests::undo::cancel_partial_trash_batch`
*  `project_panel::tests::undo::batch_trash_warns_about_unsaved_changes`

## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [ ] Unsafe blocks (if any) have justifying comments
- [ ] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

## Showcase

The screen recording below shows the trash confirmation dialog on both a
clean and dirty files, on both undo and redo flows.


https://github.com/user-attachments/assets/0f9b96f5-0357-4e3f-8ec2-141486942c89

---

Release Notes:

- Fixed issue with undoing or redoing project panel operations that
could lead to a file with unsaved edits being trashed without
confirmation.