Correct method for Patio deck attachment to roof
The normal fascia board has been removed and a 2X put on the end of the rafters to support the roof. Depending on the length I have seen this done and last for many years.
I would think if it was not up to code the home inspection would have identified that since it  looks new. It looks like they nailed through the boards. You could add hanger's if you are concerned like this. I would not tear it off unless a real problem is raised other than "looks unstable" or has leakage problems.