Another review of Yongnuo’s budget lens, the 35mm f/2, by Shooting on a Budget. In the conclusion:
The autofocus in video has improved since the YongNuo 50/1.8. With that lens, the autofocus would hunt, but fail to catch. In this, it’s slower than the Canon, but it works somewhat. It will zip close pretty quickly, but then takes a handful of zips back and forth to finally catch, about 2 seconds worth.