fix/refactor: fix GuildMember#presence getter and cleanup (#2751)

* Fix guild being a guild and not an AbstractHandler in PresenceUpdate

* update the default guild to be a Guild, and not GuildMember

* getters return null instead of undefined

* fix lint

src/client/websocket/packets/handlers/PresenceUpdate.js

@@ -35,15 +35,9 @@ class PresenceUpdateHandler extends AbstractHandler {
         });
         client.emit(Events.GUILD_MEMBER_AVAILABLE, member);
       }
-      if (member) {
-        if (client.listenerCount(Events.PRESENCE_UPDATE) === 0) {
-          guild.presences.add(Object.assign(data, { guild: this }));
-          return;
-        }
-        guild.presences.add(Object.assign(data, { guild: this }));
+      guild.presences.add(Object.assign(data, { guild }));
+      if (member && client.listenerCount(Events.PRESENCE_UPDATE)) {
         client.emit(Events.PRESENCE_UPDATE, oldPresence, member.presence);
-      } else {
-        guild.presences.add(Object.assign(data, { guild: this }));
       }
     }
   }

src/structures/GuildMember.js

@@ -124,7 +124,7 @@ class GuildMember extends Base {
       user: {
         id: this.id,
       },
-      guild: this,
+      guild: this.guild,
     });
   }
 

src/structures/Presence.js

@@ -21,18 +21,18 @@ class Presence {
 
   /**
    * The user of this presence
-   * @type {User}
+   * @type {?User}
    */
   get user() {
-    return this.client.users.get(this.userID);
+    return this.client.users.get(this.userID) || null;
   }
 
   /**
    * The member of this presence
-   * @type {GuildMember}
+   * @type {?GuildMember}
    */
   get member() {
-    return this.guild.members.get(this.userID);
+    return this.guild.members.get(this.userID) || null;
   }
 
   patch(data) {