What is the test for negligent infliction of emotional distress?

"[T]he problem [of negligent infliction of emotional distress] should be solved by the application of the principles of tort, not by the creation of exceptions to them. Legal history shows that artificial islands of exceptions, created from the fear that the legal process will not work, usually do not withstand the waves of reality and, in time, descend into oblivion." (Dillon v. Legg (1968) 68 Cal.2d 728, 747, 69 Cal.Rptr. 72, 441 P.2d 912 [Tobriner, J., admonishing this court not to do what the majority do today].)