Functional programming and reactive programming principles are not new to JavaScript, but their adoption has recently become widespread across most modern frameworks and toolkits. The ease of using these approaches has improved as we’ve finally seen the decline of legacy browsers, and as we’ve seen the introduction of functional and reactive paradigms within ES6 and ES8.
Intern, via the Leadfoot WebDriver library, provides a lot of low-level control over the browsers it uses to run tests. Tests can navigate to new pages, resize the browser window, examine elements on a page, and interact with controls like inputs and buttons. Unfortunately, with all this power can come great complexity. Many testing tasks will involve a large number of low-level operations and dealing with these can be error prone and make tests difficult to follow. Command helpers to the rescue!