What is the test for disclosing the identity of an informer in open court?

test is whether the public interest would suffer by the disclosure. Conceivably, even when the informer may be known to persons who have cause to resent the communication, disclosure in open court might still be against the public interest. A defendant who knows the identity of the informer, however, will ordinarily not be prejudiced by a refusal to disclose that identity." (People v. McShann (1958) 50 Cal.2d 802, 807, 330 P.2d 33.)