What is the test for establishing a "cause of action" under the doctrine of res judicata?

"For purposes of identifying a cause of action under the doctrine of res judicata, 'California has consistently applied the "primary rights" theory, under which the invasion of one primary right gives rise to a single cause of action.' [Citation.] But '. . . the "cause of action" is based upon the harm suffered, as opposed to the particular theory asserted by the litigant. [Citation.] Even where there are multiple legal theories upon which recovery might be predicated, one injury gives rise to only one claim for relief.' " (Branson v. Sun-Diamond Growers (1994) 24 Cal.App.4th 327, 340-341.) "Under the primary rights theory . . ., '. . . a cause of action consists of 1) a primary right possessed by the plaintiff, 2) a corresponding primary duty devolving upon the defendant, and 3) a delict or wrong done by the defendant which consists in a breach of such primary right and duty. [Citation.] Thus, two actions constitute a single cause of action if they both affect the same primary right.' " (Id. at p. 341.)

Page 6