[jfdk]

If your application has few or very simple interactions then this may make sense. If it does have complex interactions (I consider a text input updating a model field as complex) then I think tests are necessary, especially if working with a team. You want to know when you break things.

This becomes even more important if you're developing generic UI components that may be re-used in different scenarios throughout your app or company. These types of library components need to be well tested as they often have more complex interactions and are going to be used in potentially very different ways.