Node Roundup: parse5, redis-timeseries, request-as-curl

2013-12-11 00:00:00 +0000 by Alex R. Young


parse5 (GitHub: inikulin / parse5, License: MIT, npm: parse5) by Ivan Nikulin is a new HTML5 parser, based on the WhatWG HTML5 standard. It was built for a commercial project called TestCafé, when the authors found other HTML5 parsers to be too slow or inaccurate.

It's used like this:

var Parser = require('parse5').Parser;
var parser = new Parser();
var document = parser.parse('<!DOCTYPE html><html><head></head><body>Hi there!</body></html>')
var fragment = parser.parseFragment('<title>Parse5 is &#102;&#117;&#99;&#107;ing awesome!</title><h1>42</h1>');

I had a look at the source, and it doesn't look like it was made with a parser generator. It has a preprocessor, tokenizer, and special UTF-8 handling. There are no dependencies, other than nodeunit for testing. The tests were derived from html5lib, and include over 8000 test cases.

If you wanted to use it, you'll probably need to write a "tree adapter". Ivan has included an example tree adapter, which reminds me of writing SAX parser callbacks.

Ivan also sent in mods, which is a module system designed to need less boilerplate than AMD-style libraries.

Redis Time Series

Tony Sokhon sent in redis-timeseries (GitHub: tonyskn / node-redis-timeseries, License: MIT, npm: redis-timeseries), a project for managing time series data. I've used Redis a few times as a data sink for projects that need realtime statistics, and I always found it worked well for the modest amounts of data my projects generated. This project gives things a bit more structure -- you can create instances of time series and then record hits, then query them later.

A time series has a granularity, so you can store statistics at whatever resolution you require: ts.getHits('your_stats_key', '1second', ts.minutes(3), callback). This module is used by Tony's dashboard project, which can be used to make a realtime dashboard.


request-as-curl (GitHub: azproduction / node-request-as-curl, License: BSD, npm: request-as-curl) by Mikhail Davydov serialises options for http.ClientRequest into an equivalent curl command. It also works for Express.

// http.ClientRequest:
var req = request('http://google.com/', {method: 'POST', json: data}, function (error, response, expected) {
  curlify(req.req, data);
  // curl 'http://google.com' -H 'accept: application/json' -H 'content-type: application/json' -H 'connection: keep-alive' --data '{"data":"data"}' --compressed

// Express:

app.get('/', function (req) {
  // curl 'http://localhost/pewpew' -H 'x-real-ip:' -H etc...

I imagine Mikhail has been using this so he can replicate requests based on logs to aid in debugging.