yee.js

const Stream = require('stream');
const https = require('https');
const http = require('http');
const URL = require('url');

/**
 * Resumable stream via a Stream PassThrough
 * @param {string|URL} url Input url
 * @param {stream.Transform} [output=stream.PassThrough] Output stream
 * @param {Object} [meta] Meta information to pass between stuff
 * @returns {stream.Transform}
 * @example
 * const Speaker = require('speaker');
 *
 * const speaker = new Speaker({
 *   channels: 2,
 *   bitDepth: 16,
 *   sampleRate: 44100,
 * });
 *
 * require('./')('http://www.music.helsinki.fi/tmt/opetus/uusmedia/esim/a2002011001-e02.wav').pipe(speaker);
 */
function streamIt(url, output = new Stream.PassThrough(), meta = { downloaded: 0, total: 0 }) {
	if(output._destroyed) return output;

	let input;

	output.destroy = function destroy() {
		this._destroyed = true;
		if(input) {
			input.unpipe();
			input.destroy();
		}
	};

	const options = typeof url === 'string' ? URL.parse(url) : url;
	if(!options.headers) options.headers = {};

	(options.protocol === 'https:' ? https : http).get(options, (res) => {
		output.resume();
		input = res;

		if(meta.downloaded === 0) meta.total = Number(input.headers['content-length']);

		input.on('data', (chunk) => {
			meta.downloaded += Buffer.byteLength(chunk);
		});

		input.on('end', () => {
			if(meta.downloaded < meta.total) {
				input.unpipe();
				options.headers.Range = `bytes=${meta.downloaded}-`;
				streamIt(options, output, meta);
			} else {
				output.end();
			}
		});

		input.on('error', (err) => {
			if(!err) return;
			console.log(err);
			if(err.message === 'read ECONNRESET') {
				output.pause();
				return;
			}

			output.emit('error', err);
		});

		input.pipe(output, { end: false });
	});

	return output;
}

module.exports = streamIt;