Warning Date and Expiry Date for Merge Requests

Description

Warning Date and Expiry Date for Merge Requests

Overview

Would be nice if a warning date and/or an expiry date could be set for Merge Requests. After a warning date a Merge Request creator would receive a warning that they need to get somebody to accept or reject their MR before it expires. After an expiry date for an MR, that MR would be deleted.

Use cases

Projects where people create enough MRs that they lose track of their own MRs.