log(application-command): handle null cases

During the event `onStringSelectSelection` which would be called when
someone would select one role in the application form, there would be a
possibility for:

    - The `member` to be null (most likely from interacting in a
      non-guild environment, which is rare and almost impossible).

    - `event.getSelectedOptions()` to be an empty list, effectively
      meaning that a form was somehow made with no options and a user
      (or should we say member in our case) managed to interact with it.

In any case, properly log errors in the logger in case either of these
happen to be null or otherwise have unexpected values.

Suggested-by: Zabuzard <zabuza.dev@gmail.com>
Signed-off-by: Chris Sdogkos <work@chris-sdogkos.com>

Author: christolis

application/src/main/java/org/togetherjava/tjbot/features/roleapplication/CreateRoleApplicationCommand.java

@@ -20,6 +20,8 @@
 import net.dv8tion.jda.api.interactions.components.text.TextInput;
 import net.dv8tion.jda.api.interactions.components.text.TextInputStyle;
 import net.dv8tion.jda.api.interactions.modals.Modal;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import org.togetherjava.tjbot.config.Config;
 import org.togetherjava.tjbot.config.RoleApplicationSystemConfig;
@@ -53,6 +55,9 @@ public class CreateRoleApplicationCommand extends SlashCommandAdapter {
     private final RoleApplicationHandler handler;
     private final RoleApplicationSystemConfig config;
 
+    private static final Logger logger =
+            LoggerFactory.getLogger(CreateRoleApplicationCommand.class);
+
     /**
      * Constructs a new {@link CreateRoleApplicationCommand} with the specified configuration.
      * <p>
@@ -119,7 +124,13 @@ public void onStringSelectSelection(StringSelectInteractionEvent event, List<Str
         SelectOption selectOption = event.getSelectedOptions().getFirst();
         Member member = event.getMember();
 
-        if (selectOption == null || member == null) {
+        if (member == null) {
+            logger.error("Member was null during onStringSelectSelection()");
+            return;
+        }
+
+        if (selectOption == null) {
+            logger.error("selectOption was null during onStringSelectSelection()");
             return;
         }