Assert nulls before setting user's details to local cache

app/src/main/java/chat/rocket/android/RocketChatCache.kt

@@ -408,7 +408,11 @@ object RocketChatCache {
         }, BackpressureStrategy.LATEST)
     }
 
-    fun setUserId(userId: String) = setString(KEY_USER_ID, userId)
+    fun setUserId(userId: String?) {
+        userId?.let {
+            setString(KEY_USER_ID, userId)
+        }
+    }
 
     fun getUserId(): String? = getString(KEY_USER_ID, null)
 
@@ -420,7 +424,11 @@ object RocketChatCache {
 
     fun getUserName(): String? = getString(KEY_USER_NAME, null)
 
-    fun setUserUsername(username: String) = setString(KEY_USER_USERNAME, username)
+    fun setUserUsername(username: String?) {
+        username?.let {
+            setString(KEY_USER_USERNAME, username)
+        }
+    }
 
     fun getUserUsername(): String? = getString(KEY_USER_USERNAME, null)
 }
\ No newline at end of file

app/src/main/java/chat/rocket/android/service/observer/CurrentUserObserver.java

@@ -57,11 +57,14 @@ public class CurrentUserObserver extends AbstractModelObserver<RealmUser> {
         }
         listeners = new ArrayList<>();
 
-    RocketChatCache.INSTANCE.setUserId(user.getId());
-    RocketChatCache.INSTANCE.setUserUsername(user.getUsername());
-    RocketChatCache.INSTANCE.setUserName(user.getName());
+        String userId = user.getId();
+        String username = user.getUsername();
+        String name = user.getName();
 
-    final String userId = user.getId();
+
+        RocketChatCache.INSTANCE.setUserId(userId);
+        RocketChatCache.INSTANCE.setUserUsername(username);
+        RocketChatCache.INSTANCE.setUserName(name);
 
         // get and observe Room subscriptions.
         methodCall.getRoomSubscriptions().onSuccess(task -> {