// automatic constructors with a class hieararchy of depth > 2 class Base { a = 1; constructor(x: number) { this.a = x; } } class Derived extends Base { b = ''; constructor(y: string, z: string) { super(2); this.b = y; } } class Derived2 extends Derived { x = 1 y = 'hello'; } var r = new Derived(); // error var r2 = new Derived2(1); // error var r3 = new Derived('', ''); class Base2 { a: T; constructor(x: T) { this.a = x; } } class D extends Base { b: T = null; constructor(y: T, z: T) { super(2); this.b = y; } } class D2 extends D { x = 2 y: T = null; } var d = new D2(); // error var d2 = new D2(new Date()); // error var d3 = new D2(new Date(), new Date()); // ok