inlineReply.js

const { APIMessage, Structures } = require('discord.js');

class Message extends Structures.get('Message') {
  async reply(content, options) {
    const mentionRepliedUser =
      typeof ((options || content || {}).allowedMentions || {}).repliedUser ===
        'undefined'
        ? true
        : (options || content).allowedMentions.repliedUser;
    delete ((options || content || {}).allowedMentions || {}).repliedUser;

    const apiMessage =
      content instanceof APIMessage
        ? content.resolveData()
        : APIMessage.create(this.channel, content, options).resolveData();
    Object.assign(apiMessage.data, {
      message_reference: { message_id: this.id }
    });

    if (
      !apiMessage.data.allowed_mentions ||
      Object.keys(apiMessage.data.allowed_mentions).length === 0
    )
      apiMessage.data.allowed_mentions = {
        parse: ['users', 'roles', 'everyone']
      };
    if (typeof apiMessage.data.allowed_mentions.replied_user === 'undefined')
      Object.assign(apiMessage.data.allowed_mentions, {
        replied_user: mentionRepliedUser
      });

    if (Array.isArray(apiMessage.data.content)) {
      return Promise.all(
        apiMessage
          .split()
          .map(x => {
            x.data.allowed_mentions = apiMessage.data.allowed_mentions;
            return x;
          })
          .map(this.inlineReply.bind(this))
      );
    }

    const { data, files } = await apiMessage.resolveFiles();
    return this.client.api.channels[this.channel.id].messages
      .post({ data, files })
      .then(d => this.client.actions.MessageCreate.handle(d).message);
  }
}

Structures.extend('Message', () => Message);