//// [derivedClassWithAny.ts] class C { x: number; get X(): number { return 1; } foo(): number { return 1; } static y: number; static get Y(): number { return 1; } static bar(): number { return 1; } } class D extends C { x: any; get X(): any { return null; } foo(): any { return 1; } static y: any; static get Y(): any { return null; } static bar(): any { return null; } } // if D is a valid class definition than E is now not safe tranisitively through C class E extends D { x: string; get X(): string{ return ''; } foo(): string { return ''; } static y: string; static get Y(): string { return ''; } static bar(): string { return ''; } } var c: C; var d: D; var e: E; c = d; c = e; var r = c.foo(); // e.foo would return string //// [derivedClassWithAny.js] var __extends = (this && this.__extends) || function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; function __() { this.constructor = d; } __.prototype = b.prototype; d.prototype = new __(); }; var C = (function () { function C() { } Object.defineProperty(C.prototype, "X", { get: function () { return 1; }, enumerable: true, configurable: true }); C.prototype.foo = function () { return 1; }; Object.defineProperty(C, "Y", { get: function () { return 1; }, enumerable: true, configurable: true }); C.bar = function () { return 1; }; return C; })(); var D = (function (_super) { __extends(D, _super); function D() { _super.apply(this, arguments); } Object.defineProperty(D.prototype, "X", { get: function () { return null; }, enumerable: true, configurable: true }); D.prototype.foo = function () { return 1; }; Object.defineProperty(D, "Y", { get: function () { return null; }, enumerable: true, configurable: true }); D.bar = function () { return null; }; return D; })(C); // if D is a valid class definition than E is now not safe tranisitively through C var E = (function (_super) { __extends(E, _super); function E() { _super.apply(this, arguments); } Object.defineProperty(E.prototype, "X", { get: function () { return ''; }, enumerable: true, configurable: true }); E.prototype.foo = function () { return ''; }; Object.defineProperty(E, "Y", { get: function () { return ''; }, enumerable: true, configurable: true }); E.bar = function () { return ''; }; return E; })(D); var c; var d; var e; c = d; c = e; var r = c.foo(); // e.foo would return string