All programming is thinking. If AI can write good code, it can write good tests. Your job – for now – is to make sure the tests are good, if only because for the time being we're still slightly better at reasoning than the AI is. Just ask Garry Kasparov if that'll ever change.
Who is Garry Kasparov ? wikipedia hits a chess player
Chess saw no innovation since hundreds of years or something
I get your point: with IA in charge, the world will stagnate
What I do not share is your belief that this is a good outcome
One-time world chess grandmaster, who lost to Deep Blue (a chess AI) in 1997 after beating it in 1996. This marked the first time an AI beat a human on the world stage in a game of pure reasoning.
I don't believe AI will cause the world to stagnate at all. I think it will unleash humanity's creativity in a way orders of magnitude greater than history has ever seen.