Gutenberg will not ask for confirmation when clicking on the "Move to Trash Button", making it easy for a user to delete a post accidentally.
The "1 post sent to the Trash." message that appears after this is not too visible either.
Describe the solution you'd like
I think we need an intermediate step to make sure users did not click on the "Move to Trash" button by accident.
Describe alternatives you've considered
I would like to see a confirmation message, asking the user to confirm that the indeed wat to delete that post. Something like this.
Hey! Thanks for reporting this. This was discussed today in Slack. There's definitely room for improvement here.
The likely solution is similar to what you proposed with a secondary confirmation step of some sort.
That said, I believe this is a lower priority right now for a couple reasons. It's an action that can be undone. It's fairly obvious when it happens as the user is directed away from the editor to Posts or Pages.
Again, this is definitely a flow with room for improvement, but we have limited design resources to tackle this at the moment so we need to prioritize our efforts.
What if we did a double-click to verify, like in this Figma prototype?

I love that idea @richtabor!
Works for me!
Most helpful comment
What if we did a double-click to verify, like in this Figma prototype?