I have this declared class in some third party library that I can't modify: export declare class KeyboardSensor implements SensorInstance { private props; constructor(props: KeyboardSensorProps);...

When asserting that a field is definitely initialized in a class, what’s the difference between ! (exclamation point, definite assignment assertion) and the declare modifier? The following code is ...

I am trying to decorate a class with a decorator (a-la-angular style), and add methods and properties to it. this is my example decorated class: @decorator class Person{ } and this is the dec...