Let's say you want to merge the properties of two JavaScript objects: let a = { foo: 1, bar: 2 }
If you render markdown from user input, an attacker might be able to use this to inject javascript code into...
When an event listener on a DOM element throws an error, that error will be silenced and not interrupt your...
Speaker today is Henning Koch, Head of Development at makandra. This talk will be in German with English slides.
To make CSS rules dependent on the screen size, we use media queries: @media (max-width: 500px) { // rules for screen...
The linked GitHub repository is a bit like our "dev" cards deck, but groomed from a single person (Josh Branchaud...
Test-Driven Development (TDD) in its most dogmatic form (red-green-refactor in micro-iterations) can be tedious. It does...
When we write a form with date fields, we often use graphical data picker like Rome to get a consistent...
To test that an object was constructed by a given constructor function, use jasmine.any(Klass): describe('plus()', function() { it ('returns...
Browsers come with a set of built-in elements like or . When we need a new component not covered by...
A while ago I tweeted a thread about how a small JavaScript snippet, one that can fit in a single...
ActiveSupport (since 4.1) includes test helpers to manipulate time, just like the Timecop gem: To travel a relative amount of...
This is a bookmarklet you can add to Chrome or Firefox which will allow you to create a story in...
jQuery is still a useful and pragmatic library, but chances are increasingly that you’re not dependent on using it...
Capybara provides execute_script and evaluate_script to execute JavaScript code in a Selenium-controlled browser. This however is not...
CSS transitions are a simple animation framework that is built right into browsers. No need for Javascript here. They're...
Rails is split into a large number of (sub-) frameworks. The most important and central of those are activesupport (extends...
General hints on the DOM the root of the DOM is document custom elements inherit from HTMLElement. They need a...
When an AJAX request raises an exception on the server, Rails will show a minimal error page with only basic...
webpack is a very powerful asset bundler written in node.js to bundle (ES6) JavaScript modules, stylesheets, images, and other assets...
RubyMine comes with a nice way to grep through your project's files: The finder (ctrl + shift + f). Don't...
The goal is to get Jasmine specs running in a Rails project using Webpacker, with the browser based test runner...
In Ruby on Rails, all objects have a useful blank? method. It returns true for nil but also for empty...