Use SizedBox.shrink() to return an empty box

Ever needed to return an empty box (that takes no space) in Flutter?

There's a widget for that → SizedBox.shrink().

This is more performant than returning an empty Container (which is complex inside and can't be declared as a const widget).

Note that in many cases, you can avoid returning a widget in the first place.

For example, if you are inside a Row or Column, you can use the collection-if operator instead. 👇