Automating checking off checkmarks when mentioned Issue or MR is closed/merged

I believe this issue has been mentioned by @markpundsack before https://gitlab.com/gitlab-org/gitlab-ce/issues/17942 but I think this issue makes the problem and proposal somewhat simpler.

Usecase

Managing meta issues

Problem

Currently when you list issues and merge requests in an issue with a checkmark you have to manually check them off even if their status changes from open to closed/merged.

Proposal

I think auto checking the checkmarks if all of the mentioned issues or merge requests in that same list paragraph are either closed or merged is a good automation flow.

Resulting in:

Would be checked if gitlab-foss#1 (closed) is closed

• gitlab-foss#1 (closed)

Would be checked if gitlab-foss!1 (closed) is either closed or merged

• gitlab-foss!1 (closed)

Would be checked if gitlab-foss#1 (closed) and gitlab-foss!1 (closed) are both either closed or merged

• "Lorem ipsum dolor sit amet, consectetur adipiscing elit, gitlab-foss#1 (closed) sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. gitlab-foss!1 (closed)

Value

Automated meta issue management

Related issues

https://gitlab.com/gitlab-org/gitlab-ce/issues/17942 https://gitlab.com/gitlab-org/gitlab-ce/issues/23003

CC/Call to actions

@markpundsack @victorwu @JobV (as mentioned by you, you think automation is very important)

This also improves the usability of seeing how many checkmarks are checked off from the issue list:

If you are already using the closed status to view/indicate that something is done, then you should be using a checkbox in the first place.

@victorwu Perhaps, but checkboxes give the nice 3 of 3 tasks completed indication, as @dimitrieh shows above. Also, they look nicer.

We should fix this in the context of related issues. Tasks != issues.

added Accepting Merge Requests in GitLab FOSS label

moved from gitlab-foss#33193 (moved)