Most of the time.
I think checking out the branch in local and testing if the feature works should be applied for every PR that either fixes a bug, introduces a new feature or is a refactor. It's not that I don't trust my coworkers but I think all humans are fallible and are allowed to miss some things.
What I don't trust is my ability to statically check all possible changes that the code will introduce just by looking at the PR diff.
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