//// [subtypingWithObjectMembersOptionality2.ts] // Derived member is optional but base member is not, should be an error interface Base { foo: string; } interface Derived extends Base { bar: string; } interface T { Foo: Base; } interface S extends T { Foo?: Derived // error } interface T2 { 1: Base; } interface S2 extends T2 { 1?: Derived; // error } interface T3 { '1': Base; } interface S3 extends T3 { '1'?: Derived; // error } // object literal case var a: { Foo: Base; } var b: { Foo?: Derived; } var r = true ? a : b; // error //// [subtypingWithObjectMembersOptionality2.js] // object literal case var a; var b; var r = true ? a : b; // error