Repository: discordjs/discord.js
File: packages/discord.js/src/index.js (JavaScript)

Code before:
exports.ClientVoiceManager = require('./client/voice/ClientVoiceManager');
exports.DataManager = require('./managers/DataManager');
exports.DMMessageManager = require('./managers/DMMessageManager');
exports.EntitlementManager = require('./managers/EntitlementManager').EntitlementManager;
exports.GuildApplicationCommandManager = require('./managers/GuildApplicationCommandManager');
exports.GuildBanManager = require('./managers/GuildBanManager');
exports.GuildChannelManager = require('./managers/GuildChannelManager');
exports.GuildEmojiManager = require('./managers/GuildEmojiManager');
exports.GuildEmojiRoleManager = require('./managers/GuildEmojiRoleManager');
exports.GuildForumThreadManager = require('./managers/GuildForumThreadManager');
exports.GuildInviteManager = require('./managers/GuildInviteManager');
exports.GuildManager = require('./managers/GuildManager');
exports.GuildMemberManager = require('./managers/GuildMemberManager');
exports.GuildMemberRoleManager = require('./managers/GuildMemberRoleManager');
exports.GuildMessageManager = require('./managers/GuildMessageManager');
exports.GuildScheduledEventManager = require('./managers/GuildScheduledEventManager');
exports.GuildStickerManager = require('./managers/GuildStickerManager');
exports.GuildTextThreadManager = require('./managers/GuildTextThreadManager');
exports.MessageManager = require('./managers/MessageManager');
exports.PermissionOverwriteManager = require('./managers/PermissionOverwriteManager');
exports.PresenceManager = require('./managers/PresenceManager');
exports.ReactionManager = require('./managers/ReactionManager');
exports.ReactionUserManager = require('./managers/ReactionUserManager');
exports.RoleManager = require('./managers/RoleManager');
exports.StageInstanceManager = require('./managers/StageInstanceManager');
exports.SubscriptionManager = require('./managers/SubscriptionManager');
exports.ThreadManager = require('./managers/ThreadManager');
exports.ThreadMemberManager = require('./managers/ThreadMemberManager');
exports.UserManager = require('./managers/UserManager');
exports.VoiceStateManager = require('./managers/VoiceStateManager');

// Structures
exports.ActionRow = require('./structures/ActionRow');
exports.ActionRowBuilder = require('./structures/ActionRowBuilder');
exports.Activity = require('./structures/Presence').Activity;
exports.AnonymousGuild = require('./structures/AnonymousGuild');
exports.Application = require('./structures/interfaces/Application');
exports.ApplicationCommand = require('./structures/ApplicationCommand');
exports.ApplicationEmoji = require('./structures/ApplicationEmoji');
exports.ApplicationRoleConnectionMetadata =
  require('./structures/ApplicationRoleConnectionMetadata').ApplicationRoleConnectionMetadata;
exports.AutocompleteInteraction = require('./structures/AutocompleteInteraction');
exports.AutoModerationActionExecution = require('./structures/AutoModerationActionExecution');
exports.AutoModerationRule = require('./structures/AutoModerationRule');
exports.Base = require('./structures/Base');
exports.BaseGuild = require('./structures/BaseGuild');
exports.BaseGuildEmoji = require('./structures/BaseGuildEmoji');
exports.BaseGuildTextChannel = require('./structures/BaseGuildTextChannel');
exports.BaseGuildVoiceChannel = require('./structures/BaseGuildVoiceChannel');
exports.ButtonBuilder = require('./structures/ButtonBuilder');
exports.ButtonComponent = require('./structures/ButtonComponent');

Review comment (suggestion):
You're using `exports.<class>` syntax in the file, you need to either deconstruct the class name from the returned value from require (`require().class`), or move to `module.exports`

Code after:
exports.ClientVoiceManager = require('./client/voice/ClientVoiceManager');
exports.DataManager = require('./managers/DataManager');
exports.DMMessageManager = require('./managers/DMMessageManager');
exports.EntitlementManager = require('./managers/EntitlementManager').EntitlementManager;
exports.GuildApplicationCommandManager = require('./managers/GuildApplicationCommandManager');
exports.GuildBanManager = require('./managers/GuildBanManager');
exports.GuildChannelManager = require('./managers/GuildChannelManager');
exports.GuildEmojiManager = require('./managers/GuildEmojiManager');
exports.GuildEmojiRoleManager = require('./managers/GuildEmojiRoleManager');
exports.GuildForumThreadManager = require('./managers/GuildForumThreadManager');
exports.GuildInviteManager = require('./managers/GuildInviteManager');
exports.GuildManager = require('./managers/GuildManager');
exports.GuildMemberManager = require('./managers/GuildMemberManager');
exports.GuildMemberRoleManager = require('./managers/GuildMemberRoleManager');
exports.GuildMessageManager = require('./managers/GuildMessageManager');
exports.GuildScheduledEventManager = require('./managers/GuildScheduledEventManager');
exports.GuildStickerManager = require('./managers/GuildStickerManager');
exports.GuildTextThreadManager = require('./managers/GuildTextThreadManager');
exports.MessageManager = require('./managers/MessageManager');
exports.PermissionOverwriteManager = require('./managers/PermissionOverwriteManager');
exports.PresenceManager = require('./managers/PresenceManager');
exports.ReactionManager = require('./managers/ReactionManager');
exports.ReactionUserManager = require('./managers/ReactionUserManager');
exports.RoleManager = require('./managers/RoleManager');
exports.StageInstanceManager = require('./managers/StageInstanceManager');
exports.SubscriptionManager = require('./managers/SubscriptionManager').SubscriptionManager;
exports.ThreadManager = require('./managers/ThreadManager');
exports.ThreadMemberManager = require('./managers/ThreadMemberManager');
exports.UserManager = require('./managers/UserManager');
exports.VoiceStateManager = require('./managers/VoiceStateManager');

// Structures
exports.ActionRow = require('./structures/ActionRow');
exports.ActionRowBuilder = require('./structures/ActionRowBuilder');
exports.Activity = require('./structures/Presence').Activity;
exports.AnonymousGuild = require('./structures/AnonymousGuild');
exports.Application = require('./structures/interfaces/Application');
exports.ApplicationCommand = require('./structures/ApplicationCommand');
exports.ApplicationEmoji = require('./structures/ApplicationEmoji');
exports.ApplicationRoleConnectionMetadata =
  require('./structures/ApplicationRoleConnectionMetadata').ApplicationRoleConnectionMetadata;
exports.AutocompleteInteraction = require('./structures/AutocompleteInteraction');
exports.AutoModerationActionExecution = require('./structures/AutoModerationActionExecution');
exports.AutoModerationRule = require('./structures/AutoModerationRule');
exports.Base = require('./structures/Base');
exports.BaseGuild = require('./structures/BaseGuild');
exports.BaseGuildEmoji = require('./structures/BaseGuildEmoji');
exports.BaseGuildTextChannel = require('./structures/BaseGuildTextChannel');
exports.BaseGuildVoiceChannel = require('./structures/BaseGuildVoiceChannel');
exports.ButtonBuilder = require('./structures/ButtonBuilder');
exports.ButtonComponent = require('./structures/ButtonComponent');