a.js(1,14): error TS7006: Parameter 'target' implicitly has an 'any' type.
a.js(1,22): error TS7006: Parameter 'key' implicitly has an 'any' type.
a.js(1,27): error TS7006: Parameter 'index' implicitly has an 'any' type.
a.js(4,12): error TS1206: Decorators are not valid here.
a.js(4,12): error TS7006: Parameter 'x' implicitly has an 'any' type.


==== a.js (5 errors) ====
    function dec(target, key, index) {}
                 ~~~~~~
!!! error TS7006: Parameter 'target' implicitly has an 'any' type.
                         ~~~
!!! error TS7006: Parameter 'key' implicitly has an 'any' type.
                              ~~~~~
!!! error TS7006: Parameter 'index' implicitly has an 'any' type.
    
    class Foo {
        method(@dec x) {}
               ~
!!! error TS1206: Decorators are not valid here.
               ~~~~~~
!!! error TS7006: Parameter 'x' implicitly has an 'any' type.
    }
    