Generics

• Generics customize the type annotations of properties of a class
• The generics is defined with angle brackets

class HoldNumber {
  data: number;
}
class HoldString {
  data: string;
}

// Generics allows the customization of the type! TypeOfData is usually defined as T
class HoldAnything<TypeOfData> {
  data: TypeOfData;
}
// Instantiation
const holdNumber = new HoldAnything<number>();
holdNumber.data = 123;

const holdString = new HoldAnything<string>();
holdString.data = 'hey!';

interface Event {
  subject: Subjects;
  data: any;
}

abstract class Listener<T extends Event> {
  abstract subject: T['subject'];
  abstract queueGroupName: string;
  abstract onMessage(data: T['data'], msg: Message): void;
  private client: Stan;
}