How to declare a type by specifying a generic class and use it with new?

Question

typescript

Suppose we have an Observable class that is generic, and I create instances through:
new Observable<number>();
And I want it like this:

type NumberStream = Observable<number>;
new NumberStream();

but it doesn't work like that, however, like:
class NumberStream extends Observable<number> {}
And in the first case the compiler swears, in the second it doesn't, but in both cases the compilation result is executed with an error.

Answer 1

Strange, apparently I had a bug somewhere
running