==== tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithStringIndexer3.ts (5 errors) ==== // Derived type indexer must be subtype of base type indexer interface Base { foo: string; } interface Derived extends Base { bar: string; } interface Derived2 extends Derived { baz: string; } class A { [x: string]: Derived; } class B extends A { ~ !!! Class 'B' incorrectly extends base class 'A': !!! Index signatures are incompatible: !!! Type 'Base' is not assignable to type 'Derived': !!! Property 'bar' is missing in type 'Base'. [x: string]: Base; // error } class B2 extends A { [x: string]: Derived2; // ok } module Generics { class A { [x: string]: T; } class B extends A { ~~~~~~~ !!! Type 'Base' does not satisfy the constraint 'Derived': !!! Property 'bar' is missing in type 'Base'. [x: string]: Derived; // error } class B2 extends A { [x: string]: Derived2; // ok } class B3 extends A { ~~ !!! Class 'B3' incorrectly extends base class 'A': !!! Index signatures are incompatible: !!! Type 'Base' is not assignable to type 'T'. [x: string]: Base; // error } class B4 extends A { ~~ !!! Class 'B4' incorrectly extends base class 'A': !!! Index signatures are incompatible: !!! Type 'Derived' is not assignable to type 'T'. [x: string]: Derived; // error } class B5 extends A { ~~ !!! Class 'B5' incorrectly extends base class 'A': !!! Index signatures are incompatible: !!! Type 'Derived2' is not assignable to type 'T'. [x: string]: Derived2; // error } }