If doing custom getter/setter pair, you should ideally only have to annotate the getter

[jakemac53]

Today you have to annotate the setter as well with @reflectable :(.

example:

@PolymerRegister('my-element')
class MyElement extends PolymerElement {
  MyElement.created() : super.created();

  @property
  int get foo => _foo;
  @reflectable // ouch :(
  void set foo(int value) {
    _foo = value;
    notifyPath('foo', foo);
  }
  int _foo;
}

[Andersmholmgren]

yep that one bit me today

[eernstg]

See update on google/reflectable.dart#42.

[eernstg]

Done in commit 7800cb0a48b7cdf3561337de3374398b2980b9ba.