//// [derivedClassTransitivity2.ts] // subclassing is not transitive when you can remove required parameters and add optional parameters class C { foo(x: number, y: number) { } } class D extends C { foo(x: number) { } // ok to drop parameters } class E extends D { foo(x: number, y?: string) { } // ok to add optional parameters } var c: C; var d: D; var e: E; c = e; var r = c.foo(1, 1); var r2 = e.foo(1, ''); //// [derivedClassTransitivity2.js] // subclassing is not transitive when you can remove required parameters and add optional parameters var __extends = (this && this.__extends) || (function () { var extendStatics = function (d, b) { extendStatics = Object.setPrototypeOf || ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) || function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; }; return extendStatics(d, b); }; return function (d, b) { extendStatics(d, b); function __() { this.constructor = d; } d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __()); }; })(); var C = /** @class */ (function () { function C() { } C.prototype.foo = function (x, y) { }; return C; }()); var D = /** @class */ (function (_super) { __extends(D, _super); function D() { return _super !== null && _super.apply(this, arguments) || this; } D.prototype.foo = function (x) { }; // ok to drop parameters return D; }(C)); var E = /** @class */ (function (_super) { __extends(E, _super); function E() { return _super !== null && _super.apply(this, arguments) || this; } E.prototype.foo = function (x, y) { }; // ok to add optional parameters return E; }(D)); var c; var d; var e; c = e; var r = c.foo(1, 1); var r2 = e.foo(1, '');