Decorator of Class

  export function logClass(target: Function) {
      // Save link for original constructor
      const original = target;
  
      // function generate instance of class
      function construct(constructor, args) {
          const c: any = function () {
              return constructor.apply(this, args);
          }
          c.prototype = constructor.prototype;
          return new c();
      }
  
      // definition of behavior for new construtor
      const f: any = function (...args) {
          console.log(`New: ${original['name']} is created`);
          //New: Employee создан
          return construct(original, args);
      }
  
      // Copying prototype in order to instanceOf works
      f.prototype = original.prototype;
  
      // Return new constructor which overwright original constructor
      return f;
  }

  @logClass
  class Employee {
  
  }

  let emp = new Employee();
  console.log('emp instanceof Employee');
  //emp instanceof Employee
  console.log(emp instanceof Employee);
  //true