beautify.js

exports.run = async (client, msg, args) => {
  let res;
  try {
    await msg.edit("Searching for code to beautify...");
    res = await format(msg);
  } catch(e) {
    res = e;
  }
  return msg.edit(res);
};

exports.conf = {
  enabled: true,
  guildOnly: false,
  aliases: ["pretty"]
};

exports.help = {
  name: 'beautify',
  description: 'Get the last JS code block and makes it *readable*',
  usage: 'beautify [id (optional)]'
};


const { js_beautify } = require("js-beautify");

const reduceIndentation = (string) => {
  let whitespace = string.match(/^(\s+)/);
  if (!whitespace) return string;

  whitespace = whitespace[0].replace("\n", "");
  return string.split("\n").map(line => line.replace(whitespace, "")).join("\n");
};

const format = async (msg) => {
  const messages = msg.channel.messages.array().reverse();
  let code;
  const codeRegex = /```(?:js|json|javascript)?\n?((?:\n|.)+?)\n?```/ig;

  for (let m = 0; m < messages.length; m++) {
    const message = messages[m];
    const groups = codeRegex.exec(message.content);

    if (groups && groups[1].length) {
      code = groups[1];
      break;
    }
  }
  if (!code) throw new Error("No Javascript codeblock found.");

  const beautifiedCode = js_beautify(code, { indent_size: 2, brace_style: "collapse", jslint_happy: true });
  const str = await reduceIndentation(beautifiedCode);
  return (`${"```js"}\n${str}\n${"```"}`);
};