Artem Denysov denar90

collapsible markdown?

CLICK ME

yes, even hidden code blocks!

print("hello world!")

Gmail and GitHub

How to filter emails from GitHub in Gmail and flag them with labels.

The labels in this document are just examples.

Pull Request

Filter	Label

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's

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;

A few conversations have circled around user-side structural profiling. For context, see React PR #7549: Show React events in the timeline when ReactPerf is active

One particular concern is the measurement overhead. This gist has a benchmarking script (measure.js) for evaluating overhead and initial results.

Results: `performance.mark()`

Runs about 0.65µs per mark() call. Naturally, that's ~= an overhead of 1ms for 1500 mark()s.

RxJS 5 Operators By Example

⚠️ UPDATE: I have moved the contents of this gist plus more to http://www.learnrxjs.io and https://github.com/btroncone/learn-rxjs. For expanded examples, explanations, and resources, please check out this new location!

A complete list of RxJS 5 operators with easy to understand explanations and runnable examples.

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

	const puppeteer = require('puppeteer');

	(async () => {

	const browser = await puppeteer.launch();
	const page = await browser.newPage();
	// Adjustments particular to this page to ensure we hit desktop breakpoint.
	page.setViewport({width: 1000, height: 600, deviceScaleFactor: 1});

	await page.goto('https://www.chromestatus.com/samples', {waitUntil: 'networkidle'});