I've just received a merge request for a feature that we outsourced. How do you best deal with substandard quality?

It's a merge request for roughly 2k lines of code and I've already noted down 25 comments and I'm only at my first file :(

Did you have any quality targets in the contract?

@electrineer I'm not sure. I'll ask the boss.

They also have written the back-end code for that feature and my boss 'jokingly' said that he is depressed after reviewing it.

@wojtek322 if that is your bosses response to this and it makes you sad, the correct way to handle this situation is to quit

I always fall back to "if this wasn't code, but any other product, how happy would I be to receive sub-standard quality? How would I react?"

I.e. who wants a shoddy heart-rate monitor or car or umbrella

Feel your pain if your boss doesn't give a shit. Not fun