VSTS: how to require a branch to be up to date before merging (doing pull request) from that branch?

In Github, it's possible to require a branch to be up to date before one can merge it: see https://github.community/t/best-practices-for-protected-branches/10204

By also enabling Require branches to be up to date before merging you can make sure that checks are ran against the latest state of the target branch

How can one enforce this in Azure DevOps?

VSTS: how to require a branch to be up to date before merging (doing pull request) from that branch?

I once had the same request as you, but after a period of research and test, I found that this is a unique feature of github. Azure devops does not have the similar feature of Require branches to be up to date before merging in github:

Just as you said, the developers or requesters could resolve the conflict before completing the PR, However, the Reviewers will still receive these conflicting PRs. Obviously this is an interruption for reviewers.

I thought I was the only one with a special request before. Since we have the same request now, I add this request for this feature on the UserVoice site, which is main forum for product suggestions:

Azure devops support the feature "Require branches to be up to date before merging"

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