Idiomatic React code would not mix views and business logic.  (You shouldn&#x27;t <i>have</i> business logic on your React component&#x27;s; that belongs in a completely different part of that app.)<p>As for testing, you can do testing a lot of different ways, including BDD or DDD (I&#x27;m using a fair amount of DDD in the project I&#x27;m working on).  But other than being a bit easier to test than many competing techs, there&#x27;s nothing special about testing React code.  And no, basically no one outside of Facebook is using Jest; it&#x27;s a <i></i>terrible<i></i> testing tool.  (I don&#x27;t get the feeling you&#x27;ve spent much time writing or learning React?  At any rate you seem to have some odd ideas about testing and React.)<p>Aurelia is great, but I think you&#x27;re vastly overestimating the differences between an idiomatic Aurelia-based project and an idiomatic React-based project, and underestimating the flexibility which React enables.