tests/cases/conformance/es6/computedProperties/computedPropertyNames40_ES6.ts(8,5): error TS2411: Property '[""]' of type '() => Foo' is not assignable to string index type '() => Foo2'.
==== tests/cases/conformance/es6/computedProperties/computedPropertyNames40_ES6.ts (1 errors) ====
class Foo { x }
class Foo2 { x; y }
class C {
[s: string]: () => Foo2;
// Computed properties
[""]() { return new Foo }
~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2411: Property '[""]' of type '() => Foo' is not assignable to string index type '() => Foo2'.
[""]() { return new Foo2 }
}