Functional testing with qUnit
Automated testing is an essential part of application life-cycle (see Continuous Integration). In web-development we usually test: Back-end (*Unit-tests), Front-end (HTML/CSS validators, JSLint/JSHint, CSSLint, YSlow etc) and UI (functional testing). Unit-testing (Back-end, Front-end) is about checking if all the application components adhere the technical design requirements. Every unit-test simulates the application environment on which runs. Functional tests are to determine if the application as a whole ecosystem has no flaws. They run on a copy of real application environment and show if everything is ok from user prospective.