tests/cases/conformance/interfaces/interfacesExtendingClasses/interfaceExtendingClass2.ts(11,5): error TS2411: Property 'a' of type '{ toString: () => {}; }' is not assignable to string index type 'Object'. tests/cases/conformance/interfaces/interfacesExtendingClasses/interfaceExtendingClass2.ts(13,13): error TS1131: Property or signature expected. tests/cases/conformance/interfaces/interfacesExtendingClasses/interfaceExtendingClass2.ts(14,9): error TS1128: Declaration or statement expected. tests/cases/conformance/interfaces/interfacesExtendingClasses/interfaceExtendingClass2.ts(15,5): error TS1128: Declaration or statement expected. ==== tests/cases/conformance/interfaces/interfacesExtendingClasses/interfaceExtendingClass2.ts (4 errors) ==== class Foo { x: string; y() { } get Z() { return 1; } [x: string]: Object; } interface I2 extends Foo { // error a: { ~~~~ toString: () => { ~~~~~~~~~~~~~~~~~~~~~~~~~ !!! error TS2411: Property 'a' of type '{ toString: () => {}; }' is not assignable to string index type 'Object'. return 1; ~~~~~~ !!! error TS1131: Property or signature expected. }; ~ !!! error TS1128: Declaration or statement expected. } ~ !!! error TS1128: Declaration or statement expected.