YT Downloader in under 50 lines

index.js

const fs = require("fs");
const ytdl = require("ytdl-core");
const ffmpeg = require("fluent-ffmpeg");
const { createSpinner } = require("nanospinner");

var videoId = "videoID";

let hvSpinner = createSpinner("Download highest Video").start();

ytdl(videoId, { quality: "highestvideo" })
	.pipe(fs.createWriteStream(videoId + ".mp4"))
	.on("error", () => {
		hvSpinner.error();
		console.log("error downloading video");
	})
	.on("finish", () => {
		hvSpinner.success();

		let scSpinner = createSpinner("Downloading audio and combining").start();
		const audioFileStream = ytdl(videoId, { quality: "highestaudio" });
		const outputFilePath = videoId + ".mkv";
		const command = ffmpeg();

		command
			.input(videoId + ".mp4")
			.input(audioFileStream)
			.audioCodec("copy")
			.videoCodec("copy")
			.inputFormat("mp4")
			.output(outputFilePath)
			.on("end", () => {
				scSpinner.success();

				let dlSpinner = createSpinner("Delete temporary created file").start();
				fs.rmSync(videoId + ".mp4");
				dlSpinner.success();
			})
			.on("error", (err) => {
				scSpinner.error();
				console.error("Error:", err);
			})
			.run();
	});

package.json

{
  "name": "ytdl",
  "version": "1.0.0",
  "description": "Simple YouTube downloader in under 50 lines",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "fluent-ffmpeg": "^2.1.2",
    "nanospinner": "^1.1.0",
    "ytdl-core": "^4.11.5"
  }
}