perf: linear speed position getters

#9528 djs

src/util/Util.js

@@ -12,6 +12,10 @@ const isObject = d => typeof d === 'object' && d !== null;
 let deprecationEmittedForSplitMessage = false;
 let deprecationEmittedForRemoveMentions = false;
 
+const TextSortableGroupTypes = ['GUILD_TEXT', 'GUILD_ANNOUCMENT', 'GUILD_FORUM'];
+const VoiceSortableGroupTypes = ['GUILD_VOICE', 'GUILD_STAGE_VOICE'];
+const CategorySortableGroupTypes = ['GUILD_CATEGORY'];
+
 /**
  * Contains various general-purpose utility methods.
  */
@@ -747,6 +751,31 @@ class Util extends null {
     }
   }
 
+  /**
+   * Gets an array of the channel types that can be moved in the channel group. For example, a GuildText channel would
+   * return an array containing the types that can be ordered within the text channels (always at the top), and a voice
+   * channel would return an array containing the types that can be ordered within the voice channels (always at the
+   * bottom).
+   * @param {ChannelType} type The type of the channel
+   * @returns {ChannelType[]}
+   * @ignore
+   */
+  static getSortableGroupTypes(type) {
+    switch (type) {
+      case 'GUILD_TEXT':
+      case 'GUILD_ANNOUNCEMENT':
+      case 'GUILD_FORUM':
+        return TextSortableGroupTypes;
+      case 'GUILD_VOICE':
+      case 'GUILD_STAGE_VOICE':
+        return VoiceSortableGroupTypes;
+      case 'GUILD_CATEGORY':
+        return CategorySortableGroupTypes;
+      default:
+        return [type];
+    }
+  }
+
   /**
    * Calculates the default avatar index for a given user id.
    * @param {Snowflake} userId - The user id to calculate the default avatar index for