Jasmine is a great tool to unit test your JavaScript components without writing an expensive end-to-end test for...
Resources RubyGuides: Mastering Ruby Regular Expressions Using regular expressions in JavaScript Testing regular expressions visually Regular Expressions: Quantifier modes...
Learn to create test data effectively using factories. Decouple tests by having each test start with an empty database...
JavaScript code can access and manipulate the browser's DOM tree. Using JavaScript we can add interactive behavior to our...
One really simple way to check whether JavaScript Sentry integration was successful (raven-js or @sentry/browser), is to create an...
Sometimes you need to access a dev server running on localhost from another machine that is not part of the...
When using where.not with a Hash of multiple attributes, Rails applies logical NAND (NOT (A AND B)). This contrasts with...
You can use RSpec::Matchers.define_negated_matcher to define a negated version of an existing matcher. This is particularly useful...
Use option:checked to find the currently selected option: select.querySelector('option:checked') Yes, :checked, not :selected. This is the same...
Jasmine has spyOnProperty(), but it only works if the property is implemented using getter and setter functions. This is a...
TL;DR When using Cache-Control on a Rails application, make sure the Vary: Accept header is set.
Field error steps Spreewald's The...
...field should have an error and The...
...field should have the error...
...steps now...
Elasticsearch defaults to go into readonly mode when you run low on disk space (< 95%). You might then see an...
ImageMagick can convert SVGs to raster image formats. Example for PNG: convert input.svg output.png If the SVG has a...
The Interactive Advertising Bureau (IAB) is a European marketing association which has introduced a standard how advertising can be served...
Some users might use Adblock Plus or similar browser plugins to reduce the number of ads displayed. If you run...
I sometimes had the issue that I received an error when starting an existing vagrant box with vagrant up:
Similar to the Webpack Bundle Analyzer, Chrome's new Lighthouse feature … … shows a visualisation of your JavaScript bundles. It's...
From Exploring ES6: Module imports are hoisted (internally moved to the beginning of the current scope). Therefore, it doesn’t...
Rails 6.1 has a "strict loading" mode that forces the developer to preload any association they plan to use. Associations...
A flaky test is a test that is often green, but sometimes red. It may only fail on some PCs...
Basic validations Read the Rails Guide on ActiveRecord Validations. You should have an overview which kinds of validations are built...
You can configure VCR to automatically record/replay cassettes for any RSpec example tagged as :vcr or vcr: true.
RSpec is smart when using the include-matcher in combination with .not_to. One could assume that .not_to include...