Using PsiShortNamesCache will not automatically import packages after entering the class name and pressing enter

[yuriy.artamonov]

Can only say that PsiShortNamesCache is not API to implement resolve of PsiClass, it is only used as an actual cache for performance reasons.

The right direction would be

How to register a psi file created in memory into a project module?

Consider providing an implementing of extension point of com.intellij.jvm.elementProvider (com.intellij.lang.jvm.facade.JvmElementProvider interface). This is the entry point for all synthetic declarations visible to Java files. In this case you won’t need to register synthetic files in the project model, and it will be enough to generate instances of PsiClass on the fly (or cache them in a storage of your choice). Can IntelliJ IDEA index a VirtualFile in memory? That’s possible, you can i…