tests/cases/compiler/typeCheckReturnExpression.ts(1,11): error TS7011: Function expression, which lacks return-type annotation, implicitly has an 'any' return type.


==== tests/cases/compiler/typeCheckReturnExpression.ts (1 errors) ====
    var foo = () => undefined;
              ~~~~~~~~~~~~~~~
!!! error TS7011: Function expression, which lacks return-type annotation, implicitly has an 'any' return type.