Understand why we test: Low defect rate without a QA department. Customer acceptance testing can concentrate on new features...

Learn to create test data effectively using factories. Decouple tests by having each test start with an empty database...

Basic validations Read the Rails Guide on ActiveRecord Validations. You should have an overview which kinds of validations are built...

In this card we will learn to write code that scales with a large number of database records. We will...

When your code does not behave as expected, you can use a debugger statement ("breakpoint") at any point in your...

Built-in matchers Get an overview of all the matchers that are built into RSpec. Play with some of...

Learn to treat files as an ActiveRecord attribute type, like :string or :integer Research Look at the README for...

Web security basics Einführung in die Web Security 🇩🇪 provides essentials for the topic of this card. Read following chapters:

Get an idea of the varying support for HTML/CSS/JavaScript features in different browsers like Chrome, Firefox, Internet Explorer, Edge...

Exercise 1: XML On the start page of your Movie DB, show the title of a random movie that is...

Jasmine is a great tool to unit test your JavaScript components without writing an expensive end-to-end test for...

Resources Rails Guide: Internationalization API Guide to localizing a Rails application Locale-aware helpers in ActionView::Helpers::NumberHelper

Action Mailer Basics and Previews Chapter "Task H1: Sending Mail" from Agile Web Development with Rails 7.2 (in our...