Testing is becoming an essential keyword and toolkit for developers and development teams who seek to architect and implement successful and performant websites. Thanks to the unprecedented growth in automated testing tools and continuous integration (CI) solutions for all manner of web projects, testing is now table stakes for any implementation. That said, many developers find automated testing to be an altogether intimidating area of exploration. Fortunately, when paired with a development culture that values quality assurance (QA), you can focus on adding business value instead of fixing issues day in and day out. Three years ago, Yuriy Gerasimov (Senior Back-End Engineer at Tag1 Consulting ) gave a talk at DrupalCon New Orleans about some of the key ideas that Drupal developers need to understand in order to implement robust testing infrastructures and to foster a testing-oriented development culture that yields unforeseen business dividends across a range of projects. In this four-part blog series, we summarize some of the most important conclusions from Yuriy’s talk. And in this third installment, we’ll take a closer look at two of the most essential parts of any testing toolkit: unit testing and functional testing. Unit testing Unit testing is a particularly fascinating topic,...