I have installed TestNG from Eclipse MarketPlace. I've checked it in Installed Software:
However, when I open Run As, there is not TestNG but Java Application and Maven. When I go to Window -> Show View -> Other -> Java folder, there it not TestNG.
I found a similar question: TestNG not showing up in preferences- JDK 1.8 but it hasn't been solved until today.
Also I've got some error in Error Log but I have no idea if it's related to TestNG:
Would someone help me to solve this problem? Thank you.
I also checked this question:
TestNG option not showing in RunAs option in Eclipse
The version of Eclipse is 4.27.0 and JDK is 18.0.1.1
Okay, I think I've solved the problem. After uninstalling TestNG, I noticed that "TestNG P2 Feature" remained in Installed Software. I manually uninstalled it, then re-installed TestNG from Eclipse Marketplace. Now I can see TestNG in Window -> Show View -> Other -> Java folder. I still don't know what caused this problem, but this is how I fixed it.