==== tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithCallSignaturesA.ts (1 errors) ====
    declare function foo3(cb: (x: number) => number): typeof cb;
    var r5 = foo3((x: number) => ''); // error
                  ~~~~~~~~~~~~~~~~~
!!! Argument of type '(x: number) => string' is not assignable to parameter of type '(x: number) => number'.