From da05a8856b11cc1bf0df424c88a1cf9573e5b654 Mon Sep 17 00:00:00 2001
From: Suneet Tipirneni <77477100+suneettipirneni@users.noreply.github.com>
Date: Mon, 17 Jan 2022 14:17:34 -0500
Subject: [PATCH] feat(interaction): add `isRepliable` type guard (#7259)

Co-authored-by: Almeida <almeidx@pm.me>
Co-authored-by: Rodry <38259440+ImRodry@users.noreply.github.com>
---
 packages/discord.js/src/structures/Interaction.js |  8 ++++++++
 packages/discord.js/typings/index.d.ts            | 12 ++++++++++++
 packages/discord.js/typings/index.test-d.ts       | 11 +++++++++++
 3 files changed, 31 insertions(+)

diff --git a/packages/discord.js/src/structures/Interaction.js b/packages/discord.js/src/structures/Interaction.js
index 03a7606f3..b8bc14939 100644
--- a/packages/discord.js/src/structures/Interaction.js
+++ b/packages/discord.js/src/structures/Interaction.js
@@ -226,6 +226,14 @@ class Interaction extends Base {
       ComponentType[this.componentType] === ComponentType.SelectMenu
     );
   }
+
+  /**
+   * Indicates whether this interaction can be replied to.
+   * @returns {boolean}
+   */
+  isRepliable() {
+    return ![InteractionType.Ping, InteractionType.ApplicationCommandAutocomplete].includes(InteractionType[this.type]);
+  }
 }
 
 module.exports = Interaction;
diff --git a/packages/discord.js/typings/index.d.ts b/packages/discord.js/typings/index.d.ts
index 671285462..b3c0fd179 100644
--- a/packages/discord.js/typings/index.d.ts
+++ b/packages/discord.js/typings/index.d.ts
@@ -324,6 +324,17 @@ export type GuildCacheMessage<Cached extends CacheType> = CacheTypeReducer<
   Message | APIMessage
 >;
 
+export interface InteractionResponseFields<Cached extends CacheType = CacheType> {
+  reply(options: InteractionReplyOptions & { fetchReply: true }): Promise<GuildCacheMessage<Cached>>;
+  reply(options: string | MessagePayload | InteractionReplyOptions): Promise<void>;
+  deleteReply(): Promise<void>;
+  editReply(options: string | MessagePayload | WebhookEditMessageOptions): Promise<GuildCacheMessage<Cached>>;
+  deferReply(options: InteractionDeferReplyOptions & { fetchReply: true }): Promise<GuildCacheMessage<Cached>>;
+  deferReply(options?: InteractionDeferReplyOptions): Promise<void>;
+  fetchReply(): Promise<GuildCacheMessage<Cached>>;
+  followUp(options: string | MessagePayload | InteractionReplyOptions): Promise<GuildCacheMessage<Cached>>;
+}
+
 export abstract class CommandInteraction<Cached extends CacheType = CacheType> extends Interaction<Cached> {
   public readonly command: ApplicationCommand | ApplicationCommand<{ guild: GuildResolvable }> | null;
   public options: Omit<
@@ -1327,6 +1338,7 @@ export class Interaction<Cached extends CacheType = CacheType> extends Base {
   public isUserContextMenuCommand(): this is UserContextMenuCommandInteraction<Cached>;
   public isMessageComponent(): this is MessageComponentInteraction<Cached>;
   public isSelectMenu(): this is SelectMenuInteraction<Cached>;
+  public isRepliable(): this is this & InteractionResponseFields<Cached>;
 }
 
 export class InteractionCollector<T extends Interaction> extends Collector<Snowflake, T> {
diff --git a/packages/discord.js/typings/index.test-d.ts b/packages/discord.js/typings/index.test-d.ts
index f8e3ceab9..140c58343 100644
--- a/packages/discord.js/typings/index.test-d.ts
+++ b/packages/discord.js/typings/index.test-d.ts
@@ -92,6 +92,7 @@ import {
   ButtonComponent,
   SelectMenuComponent,
   ActionRowComponent,
+  InteractionResponseFields,
 } from '.';
 import { expectAssignable, expectDeprecated, expectNotAssignable, expectNotType, expectType } from 'tsd';
 
@@ -1124,6 +1125,16 @@ client.on('interactionCreate', async interaction => {
     expectType<string | null>(interaction.options.getSubcommandGroup(booleanValue));
     expectType<string | null>(interaction.options.getSubcommandGroup(false));
   }
+
+  if (interaction.isRepliable()) {
+    expectAssignable<InteractionResponseFields>(interaction);
+    interaction.reply('test');
+  }
+
+  if (interaction.isChatInputCommand() && interaction.isRepliable()) {
+    expectAssignable<CommandInteraction>(interaction);
+    expectAssignable<InteractionResponseFields>(interaction);
+  }
 });
 
 declare const shard: Shard;