Back in July 2021, Turkey announced that passengers arriving in the country would be subject to random "sampling" PCR tests, with any positive cases carted off to quarantine for 14 days.
This Turkish Airlines page indicates that the policy is still in place as of January 2022, although the quarantine period has been cut to 7 days (or less if you test negative on the 5th day), and anecdotal evidence says only passengers with a fever are likely to get tested. Any official, up-to-date sources regarding the current policy?
This seems awfully shortsighted to me, since transit passengers are exempted, meaning travelers now have a large incentive to not do a stopover and spend time/money in the country.