That looks fine and will generally work, except when the current branch is one of the ones to be deleted.
The script in OP handles that edge case by switching to the main branch before deleting. That may or may not be intuitive but I think it's a reasonable response. The script also prints error messages for various other bad inputs. Once you strip all that out it's only a few lines long.
The script in OP handles that edge case by switching to the main branch before deleting. That may or may not be intuitive but I think it's a reasonable response. The script also prints error messages for various other bad inputs. Once you strip all that out it's only a few lines long.