I am using Visual Studio Scrum process template and TFS 2013. Is there a way to define a checkin policy that would constraint developers to always use a Task item to associate with their changesets?
I have seen developers associated their changesets with PBI and Bugs without creating any Task items for those.
Yes, you could do it be defining a Work Item Query Policy.
Here is an example:
Create a new query like this (could be more advanced if needed)
Create the check-in policy and choose "Work Item Query Policy" and choose the query you have just made
If you now check-in you will get the warning that you haven't associated any items from that query - in this case, any tasks
I hope that was what you were looking for :)