types: replace Mixins with interface merging (#10094)

* types(TextBasedChannelMixin): refactor to user interface merging instead

* types(WebhookMixin): refactor to interface merging

* fix: ignore empty-interface tslint errors

---------

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/discord.js/typings/index.d.ts

@@ -647,7 +647,9 @@ export class BaseGuildEmoji extends Emoji {
   public requiresColons: boolean | null;
 }
 
-export class BaseGuildTextChannel extends TextBasedChannelMixin(GuildChannel, true) {
+// tslint:disable-next-line no-empty-interface
+export interface BaseGuildTextChannel extends TextBasedChannelFields<true>, GuildChannel {}
+export class BaseGuildTextChannel extends GuildChannel {
   protected constructor(guild: Guild, data?: RawGuildChannelData, client?: Client<true>, immediatePatch?: boolean);
   public defaultAutoArchiveDuration?: ThreadAutoArchiveDuration;
   public defaultThreadRateLimitPerUser: number | null;
@@ -666,10 +668,11 @@ export class BaseGuildTextChannel extends TextBasedChannelMixin(GuildChannel, tr
   public setType(type: ChannelType.GuildAnnouncement, reason?: string): Promise<NewsChannel>;
 }
 
-export class BaseGuildVoiceChannel extends TextBasedChannelMixin(GuildChannel, true, [
+// tslint:disable-next-line no-empty-interface
-  'lastPinTimestamp',
+export interface BaseGuildVoiceChannel
-  'lastPinAt',
+  extends Omit<TextBasedChannelFields<true>, 'lastPinTimestamp' | 'lastPinAt'>,
-]) {
+    GuildChannel {}
+export class BaseGuildVoiceChannel extends GuildChannel {
   public constructor(guild: Guild, data?: RawGuildChannelData);
   public bitrate: number;
   public get full(): boolean;
@@ -1289,13 +1292,14 @@ export interface ResolvedFile {
   contentType?: string;
 }
 
-export class DMChannel extends TextBasedChannelMixin(BaseChannel, false, [
+// tslint:disable-next-line no-empty-interface
-  'bulkDelete',
+export interface DMChannel
-  'fetchWebhooks',
+  extends Omit<
-  'createWebhook',
+      TextBasedChannelFields<false>,
-  'setRateLimitPerUser',
+      'bulkDelete' | 'fetchWebhooks' | 'createWebhook' | 'setRateLimitPerUser' | 'setNSFW'
-  'setNSFW',
+    >,
-]) {
+    BaseChannel {}
+export class DMChannel extends BaseChannel {
   private constructor(client: Client<true>, data?: RawDMChannelData);
   public flags: Readonly<ChannelFlagsBitField>;
   public recipientId: Snowflake;
@@ -1574,7 +1578,8 @@ export class GuildMemberFlagsBitField extends BitField<GuildMemberFlagsString> {
   public static resolve(bit?: BitFieldResolvable<GuildMemberFlagsString, GuildMemberFlags>): number;
 }
 
-export class GuildMember extends PartialTextBasedChannel(Base) {
+export interface GuildMember extends PartialTextBasedChannelFields<false>, Base {}
+export class GuildMember extends Base {
   private constructor(client: Client<true>, data: RawGuildMemberData, guild: Guild);
   private _roles: Snowflake[];
   public avatar: string | null;
@@ -1925,7 +1930,9 @@ export class InteractionCollector<Interaction extends CollectedInteraction> exte
   public once(event: string, listener: (...args: any[]) => void): this;
 }
 
-export class InteractionWebhook extends PartialWebhookMixin() {
+// tslint:disable-next-line no-empty-interface
+export interface InteractionWebhook extends PartialWebhookFields {}
+export class InteractionWebhook {
   public constructor(client: Client<true>, id: Snowflake, token: string);
   public readonly client: Client<true>;
   public token: string;
@@ -2469,17 +2476,21 @@ export interface DefaultReactionEmoji {
   name: string | null;
 }
 
-export abstract class ThreadOnlyChannel extends TextBasedChannelMixin(GuildChannel, true, [
+export interface ThreadOnlyChannel
-  'send',
+  extends Omit<
-  'lastMessage',
+      TextBasedChannelFields,
-  'lastPinAt',
+      | 'send'
-  'bulkDelete',
+      | 'lastMessage'
-  'sendTyping',
+      | 'lastPinAt'
-  'createMessageCollector',
+      | 'bulkDelete'
-  'awaitMessages',
+      | 'sendTyping'
-  'createMessageComponentCollector',
+      | 'createMessageCollector'
-  'awaitMessageComponent',
+      | 'awaitMessages'
-]) {
+      | 'createMessageComponentCollector'
+      | 'awaitMessageComponent'
+    >,
+    GuildChannel {}
+export abstract class ThreadOnlyChannel extends GuildChannel {
   public type: ChannelType.GuildForum | ChannelType.GuildMedia;
   public threads: GuildForumThreadManager;
   public availableTags: GuildForumTag[];
@@ -3139,11 +3150,11 @@ export interface PrivateThreadChannel extends ThreadChannel<false> {
   type: ChannelType.PrivateThread;
 }
 
-export class ThreadChannel<ThreadOnly extends boolean = boolean> extends TextBasedChannelMixin(BaseChannel, true, [
+// tslint:disable-next-line no-empty-interface
-  'fetchWebhooks',
+export interface ThreadChannel<ThreadOnly extends boolean = boolean>
-  'createWebhook',
+  extends Omit<TextBasedChannelFields<true>, 'fetchWebhooks' | 'createWebhook' | 'setNSFW'>,
-  'setNSFW',
+    BaseChannel {}
-]) {
+export class ThreadChannel<ThreadOnly extends boolean = boolean> extends BaseChannel {
   private constructor(guild: Guild, data?: RawThreadChannelData, client?: Client<true>);
   public archived: boolean | null;
   public get archivedAt(): Date | null;
@@ -3238,7 +3249,9 @@ export class Typing extends Base {
   };
 }
 
-export class User extends PartialTextBasedChannel(Base) {
+// tslint:disable-next-line no-empty-interface
+export interface User extends PartialTextBasedChannelFields<false>, Base {}
+export class User extends Base {
   protected constructor(client: Client<true>, data: RawUserData);
   private _equals(user: APIUser): boolean;
 
@@ -3491,7 +3504,9 @@ export class VoiceState extends Base {
   public edit(options: VoiceStateEditOptions): Promise<this>;
 }
 
-export class Webhook extends WebhookMixin() {
+// tslint:disable-next-line no-empty-interface
+export interface Webhook extends WebhookFields {}
+export class Webhook {
   private constructor(client: Client<true>, data?: RawWebhookData);
   public avatar: string | null;
   public avatarURL(options?: ImageURLOptions): string | null;
@@ -3537,7 +3552,9 @@ export class Webhook extends WebhookMixin() {
   public send(options: string | MessagePayload | WebhookMessageCreateOptions): Promise<Message>;
 }
 
-export class WebhookClient extends WebhookMixin(BaseClient) {
+// tslint:disable-next-line no-empty-interface
+export interface WebhookClient extends WebhookFields, BaseClient {}
+export class WebhookClient extends BaseClient {
   public constructor(data: WebhookClientData, options?: WebhookClientOptions);
   public readonly client: this;
   public options: WebhookClientOptions;
@@ -4485,22 +4502,6 @@ export class VoiceStateManager extends CachedManager<Snowflake, VoiceState, type
 
 export type Constructable<Entity> = abstract new (...args: any[]) => Entity;
 
-/** @internal */
-export function PartialTextBasedChannel<Entity>(
-  Base?: Constructable<Entity>,
-): Constructable<Entity & PartialTextBasedChannelFields<false>>;
-
-/** @internal */
-export function TextBasedChannelMixin<
-  Entity,
-  InGuild extends boolean = boolean,
-  IgnoredFields extends keyof TextBasedChannelFields<InGuild> = never,
->(
-  Base?: Constructable<Entity>,
-  inGuild?: InGuild,
-  ignore?: IgnoredFields[],
-): Constructable<Entity & Omit<TextBasedChannelFields<InGuild>, IgnoredFields>>;
-
 export interface PartialTextBasedChannelFields<InGuild extends boolean = boolean> {
   send(options: string | MessagePayload | MessageCreateOptions): Promise<Message<InGuild>>;
 }
@@ -4531,11 +4532,6 @@ export interface TextBasedChannelFields<InGuild extends boolean = boolean>
   setNSFW(nsfw?: boolean, reason?: string): Promise<this>;
 }
 
-/** @internal */
-export function PartialWebhookMixin<Entity>(Base?: Constructable<Entity>): Constructable<Entity & PartialWebhookFields>;
-/** @internal */
-export function WebhookMixin<Entity>(Base?: Constructable<Entity>): Constructable<Entity & WebhookFields>;
-
 /** @internal */
 export interface PartialWebhookFields {
   id: Snowflake;