This post shows how we measure and interpret load times on Wikipedia. It also explains what real-user metrics are, and how percentiles work. Navigation Timing When a browser loads a page, the page can include program code (JavaScript). This program will run inside the browser, alongside the page. This makes it...

Today, I’d like to challenge the assert.ok and assert.not* methods. I believe they may’ve become an anti-pattern. assert.ok Using assert.ok() indicates one of two problems: The former necessitates improvement to the code being tested. The latter comes with two additional caveats: Common examples: assert.not Using...

How did Apple create Safari, and what is PhantomJS? Safari In January 2003 Apple announced Safari, their new web browser for Mac. The Safari team had just spent 2002 building Safari atop KHTML and KJS, the KDE layout and javascript engines developed for Konqueror. The Safari team kept the codebase somewhat modular....

re·buke verb express sharp disapproval or criticism of (someone) because of their behavior or actions “she had rebuked him for drinking too much“ “the judge publicly rebuked the jury“ noun an expression of sharp disapproval or criticism “he hadn’t meant it as a rebuke, but Neil flinched“ (from the Oxford English...