//// [bases.ts] interface I { x; } class B { constructor() { this.y: any; } } class C extends B implements I { constructor() { this.x: any; } } new C().x; new C().y; //// [bases.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; } d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __()); }; var B = (function () { function B() { this.y; any; } return B; })(); var C = (function (_super) { __extends(C, _super); function C() { this.x; any; } return C; })(B); new C().x; new C().y;