Decorator cannot set on top of overload method

[falsandtru]

I want to use a following design.

// hello.ts
class C {
  @readonly
  method()
  method() { }
}

function readonly(target, key, descriptor) {
  descriptor.writable = false;
}

$ node built/local/tsc.js hello.ts --noEmit --target ES5
hello.ts(2,3): error TS1206: Decorators are not valid here.

[mhegazy]

Decorating an overload does not make much sense, the overload does not exist at runtime, but this when the decoration happenes. you should be decorating the implementation instead.

class C {   
    method(a: string);
    method(b: number);
    method();
    @readonly
    method(a?:any) { }
}

[falsandtru]

It is regrettable. Thanks for your answer.

[Buildstarted]

Seems to me the decorator should just filter down to the implementation. cleaner to have the overloads closer to each other and the @decorator on top of them all - the decorator can easily get lost in the clutter of doc comments and what not.

[DanielRosenwasser]

That's a bad error message though, so I've filed #6064.