Possbile bug, identifier will be just a jid, device id missing.

[goors]

libsignal-protocol-javascript/test/InMemorySignalProtocolStore.js

Line 59 in f5a838f

var address = new libsignal.SignalProtocolAddress.fromString(identifier);

I was using that and could not get it to work since libsignal complains for address.toString() with error can not found device or similar. Adding

let address = new this.libsignal.SignalProtocolAddress.fromString(identifier + "." + this.get("registrationId").toString());

resolved issue.