Aleksey Kulikov alekseykulikov

In reply to Jeremy's tweet, that underscore is 3x smaller (simpler?) than Lodash! https://twitter.com/jashkenas/status/568564455937839106

Apparently, it's only true if you use <script> tag, but if you use lodash's module feature and build your project with browserify(or webpack) you get different numbers. In simple cases underscore can be 4-6 times bigger.

15020 bundle-lodash-without.js
 4820 bundle-lodash-without.min.js
 1647 bundle-lodash-without.min.js.gz

Recently CSS has got a lot of negativity. But I would like to defend it and show, that with good naming convention CSS works pretty well.

My 3 developers team has just developed React.js application with 7668 lines of CSS (and just 2 !important). During one year of development we had 0 issues with CSS. No refactoring typos, no style leaks, no performance problems, possibly, it is the most stable part of our application.

Here are main principles we use to write CSS for modern (IE11+) browsers:

SUIT CSS naming conventions + SUIT CSS design principles;
PostCSS + CSSNext. Future CSS syntax like variables, nesting, and autoprefixer are good enough;
Flexbox is awesome. No need for grid framework;
Normalize.css, base styles and variables are solid foundation for all components;

In this article, I would like to share three features of PageSpeed Insights (PSI), that is not easy to find in the official documentation. I discovered them while hacking on the Lighthouse plugin and integrating PSI to Treo.sh.

For a context, PSI is a simple yet powerful API by Google, that audits your page using Lighthouse and provides real-world users' data from Chrome UX Report (CrUX).

1. Audit many categories with one request

By default, PSI API returns only performance category. It's possible to pass ?category argument multiple times and get a report with many Lighthouse categories using one request (available categories: performance, accessibility, best-practices, seo, pwa).

curl -i "https://www.googleapis.com/pagespe

	/**
	* Required node >= v0.11.2
	* usage: node --harmony index.js
	*/

	var fs = require('fs');
	var run = require('./run');

	function readFile(filename) {
	return fs.readFile.bind(fs, filename, 'utf-8');

	export PATH=/usr/local/bin:/usr/local/share/npm/bin:$PATH
	PS1="\w \[\033[32m\]\$(parse_git_branch) \[\033[37m\]$\[\033[00m\] "

	alias ll='ls -alFG'

	# git aliases
	alias ga='git add -A && gc'
	alias gb='git branch'
	alias gc='git commit -v'
	alias gd='git diff'

	{
	// validate code
	"freeze": true, // prohibits overwriting prototypes
	"unused": true,
	"undef": true,

	// relaxing options
	"expr": true, // suppresses warnings about expressive expressions, like ?
	"laxbreak": true, // allow line breaking
	"lastsemic": true, // suppresses warnings about last missing semicolon

	{
	"preset": "node-style-guide",
	"requireCamelCaseOrUpperCaseIdentifiers": "ignoreProperties", // for external APIs
	"requireCapitalizedComments": null, // why???
	"requireCurlyBraces": null, // allow one lines
	"requireTrailingComma": null, optional

	// personal style
	"maximumLineLength": { // 80 is a goal, but sometimes it's necessary
	"value": 120,

	var co = require('co')

	/**
	* Wrap koa-like generators to express-like callbacks.
	*
	* @param {GeneratorFunction} fn
	* @return {Function}
	*/

	modules.exports = function wrap(fn) {

	$ npm i -g browserify uglify-js pretty-bytes
	$ npm i react
	$ browserify node_modules/react \| uglifyjs -m \| gzip \| wc -c \| pretty-bytes
	> 51.58 kB
	$ npm i backbone jquery
	$ browserify node_modules/backbone \| uglifyjs -m \| gzip \| wc -c \| pretty-bytes
	> 41.99 kB
	$ npm i socket.io-client
	$ browserify node_modules/socket.io-client \| uglifyjs -m \| gzip \| wc -c \| pretty-bytes
	> 20.64 kB

	{
	"userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/85.0.4161.0 Safari/537.36",
	"environment": {
	"networkUserAgent": "Mozilla/5.0 (Linux; Android 6.0.1; Moto G (4)) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3963.0 Mobile Safari/537.36 Chrome-Lighthouse",
	"hostUserAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/85.0.4161.0 Safari/537.36",
	"benchmarkIndex": 1206
	},
	"lighthouseVersion": "6.0.0",
	"fetchTime": "2020-05-31T13:08:20.759Z",
	"requestedUrl": "https://developers.google.com/",