ClassDecorator

ClassDecorator.ts

@logClass
class Person {
    public name: string;

    constructor(name : string) {
        this.name = name;
    }

    public myMethod() {
        console.log('method works!');
    }

}

function logClass<TFunction extends Function>(target: TFunction): TFunction {
    const newConstructor = function(...args) {
        console.log(`New instance of ${target.name}: ${args}`);
        return target.apply(this, args);
    }

    newConstructor.prototype = target.prototype;

    return newConstructor as unknown as TFunction;
}

const p1 = new Person('Person 1');
const p2 = new Person('Person 2');
p1.myMethod();
console.log(p1 instanceof Person)