feat: add support for autocomplete interactions (#6672)

Co-authored-by: Suneet Tipirneni <suneettipirneni@icloud.com>

src/structures/ApplicationCommand.js

@@ -140,6 +140,7 @@ class ApplicationCommand extends Base {
    * @property {ApplicationCommandOptionType|number} type The type of the option
    * @property {string} name The name of the option
    * @property {string} description The description of the option
+   * @property {boolean} [autocomplete] Whether the option is an autocomplete option
    * @property {boolean} [required] Whether the option is required
    * @property {ApplicationCommandOptionChoice[]} [choices] The choices of the option for the user to pick from
    * @property {ApplicationCommandOptionData[]} [options] Additional options if this option is a subcommand (group)
@@ -199,6 +200,7 @@ class ApplicationCommand extends Base {
       command.name !== this.name ||
       ('description' in command && command.description !== this.description) ||
       ('version' in command && command.version !== this.version) ||
+      ('autocomplete' in command && command.autocomplete !== this.autocomplete) ||
       (commandType && commandType !== this.type) ||
       // Future proof for options being nullable
       // TODO: remove ?? 0 on each when nullable
@@ -254,6 +256,7 @@ class ApplicationCommand extends Base {
       option.name !== existing.name ||
       optionType !== existing.type ||
       option.description !== existing.description ||
+      option.autocomplete !== existing.autocomplete ||
       (option.required ?? (['SUB_COMMAND', 'SUB_COMMAND_GROUP'].includes(optionType) ? undefined : false)) !==
         existing.required ||
       option.choices?.length !== existing.choices?.length ||
@@ -303,6 +306,7 @@ class ApplicationCommand extends Base {
    * @property {string} name The name of the option
    * @property {string} description The description of the option
    * @property {boolean} [required] Whether the option is required
+   * @property {boolean} [autocomplete] Whether the option is an autocomplete option
    * @property {ApplicationCommandOptionChoice[]} [choices] The choices of the option for the user to pick from
    * @property {ApplicationCommandOption[]} [options] Additional options if this option is a subcommand (group)
    * @property {ChannelType[]} [channelTypes] When the option type is channel,
@@ -332,6 +336,7 @@ class ApplicationCommand extends Base {
       description: option.description,
       required:
         option.required ?? (stringType === 'SUB_COMMAND' || stringType === 'SUB_COMMAND_GROUP' ? undefined : false),
+      autocomplete: option.autocomplete,
       choices: option.choices,
       options: option.options?.map(o => this.transformOption(o, received)),
       [channelTypesKey]: received

src/structures/AutocompleteInteraction.js

@@ -0,0 +1,107 @@
+'use strict';
+
+const CommandInteractionOptionResolver = require('./CommandInteractionOptionResolver');
+const Interaction = require('./Interaction');
+const { InteractionResponseTypes, ApplicationCommandOptionTypes } = require('../util/Constants');
+
+/**
+ * Represents an autocomplete interaction.
+ * @extends {Interaction}
+ */
+class AutocompleteInteraction extends Interaction {
+  constructor(client, data) {
+    super(client, data);
+
+    /**
+     * The id of the channel this interaction was sent in
+     * @type {Snowflake}
+     * @name AutocompleteInteraction#channelId
+     */
+
+    /**
+     * The invoked application command's id
+     * @type {Snowflake}
+     */
+    this.commandId = data.data.id;
+
+    /**
+     * The invoked application command's name
+     * @type {string}
+     */
+    this.commandName = data.data.name;
+
+    /**
+     * Whether this interaction has already received a response
+     * @type {boolean}
+     */
+    this.responded = false;
+
+    /**
+     * The options passed to the command
+     * @type {CommandInteractionOptionResolver}
+     */
+    this.options = new CommandInteractionOptionResolver(
+      this.client,
+      data.data.options?.map(option => this.transformOption(option, data.data.resolved)) ?? [],
+    );
+  }
+
+  /**
+   * The invoked application command, if it was fetched before
+   * @type {?ApplicationCommand}
+   */
+  get command() {
+    const id = this.commandId;
+    return this.guild?.commands.cache.get(id) ?? this.client.application.commands.cache.get(id) ?? null;
+  }
+
+  /**
+   * Transforms an option received from the API.
+   * @param {APIApplicationCommandOption} option The received option
+   * @returns {CommandInteractionOption}
+   * @private
+   */
+  transformOption(option) {
+    const result = {
+      name: option.name,
+      type: ApplicationCommandOptionTypes[option.type],
+    };
+
+    if ('value' in option) result.value = option.value;
+    if ('options' in option) result.options = option.options.map(opt => this.transformOption(opt));
+    if ('focused' in option) result.focused = option.focused;
+
+    return result;
+  }
+
+  /**
+   * Sends results for the autocomplete of this interaction.
+   * @param {ApplicationCommandOptionChoice[]} options The options for the autocomplete
+   * @returns {Promise<void>}
+   * @example
+   * // respond to autocomplete interaction
+   * interaction.respond([
+   *  {
+   *    name: 'Option 1',
+   *    value: 'option1',
+   *  },
+   * ])
+   *  .then(console.log)
+   *  .catch(console.error);
+   */
+  async respond(options) {
+    if (this.responded) throw new Error('INTERACTION_ALREADY_REPLIED');
+
+    await this.client.api.interactions(this.id, this.token).callback.post({
+      data: {
+        type: InteractionResponseTypes.APPLICATION_COMMAND_AUTOCOMPLETE_RESULT,
+        data: {
+          choices: options,
+        },
+      },
+    });
+    this.responded = true;
+  }
+}
+
+module.exports = AutocompleteInteraction;

src/structures/BaseCommandInteraction.js

@@ -16,13 +16,6 @@ class BaseCommandInteraction extends Interaction {
   constructor(client, data) {
     super(client, data);
 
-    /**
-     * The channel this interaction was sent in
-     * @type {?TextBasedChannels}
-     * @name BaseCommandInteraction#channel
-     * @readonly
-     */
-
     /**
      * The id of the channel this interaction was sent in
      * @type {Snowflake}
@@ -138,6 +131,7 @@ class BaseCommandInteraction extends Interaction {
    * @typedef {Object} CommandInteractionOption
    * @property {string} name The name of the option
    * @property {ApplicationCommandOptionType} type The type of the option
+   * @property {boolean} [autocomplete] Whether the option is an autocomplete option
    * @property {string|number|boolean} [value] The value of the option
    * @property {CommandInteractionOption[]} [options] Additional options if this option is a
    * subcommand (group)

src/structures/CommandInteractionOptionResolver.js

@@ -239,6 +239,18 @@ class CommandInteractionOptionResolver {
     const option = this._getTypedOption(name, '_MESSAGE', ['message'], required);
     return option?.message ?? null;
   }
+
+  /**
+   * Gets the focused option.
+   * @param {boolean} [getFull=false] Whether to get the full option object
+   * @returns {string|number|ApplicationCommandOptionChoice}
+   * The value of the option, or the whole option if getFull is true
+   */
+  getFocused(getFull = false) {
+    const focusedOption = this._hoistedOptions.find(option => option.focused);
+    if (!focusedOption) throw new TypeError('AUTOCOMPLETE_INTERACTION_OPTION_NO_FOCUSED_OPTION');
+    return getFull ? focusedOption : focusedOption.value;
+  }
 }
 
 module.exports = CommandInteractionOptionResolver;

src/structures/Interaction.js

@@ -160,6 +160,14 @@ class Interaction extends Base {
     return InteractionTypes[this.type] === InteractionTypes.APPLICATION_COMMAND && typeof this.targetId !== 'undefined';
   }
 
+  /**
+   * Indicates whether this interaction is an {@link AutocompleteInteraction}
+   * @returns {boolean}
+   */
+  isAutocomplete() {
+    return InteractionTypes[this.type] === InteractionTypes.APPLICATION_COMMAND_AUTOCOMPLETE;
+  }
+
   /**
    * Indicates whether this interaction is a {@link MessageComponentInteraction}.
    * @returns {boolean}