This issue was originally filed by def...@gmail.com

I've two polymer elements that share the same dart file. In the dart file I declare both the PolymerElement classes.

Until polymer 0.15.0+1 it was working fine. I've updated the project to polymer 0.15.1 and now I get this exception:

    Exception: Already registered (Polymer) prototype for element my-polymer-a

Where my-polymer-a is the first declared polymer.

I think the polymer transformer is trying to register it two times, the first scanning the my-polymer-a html file, the second when scanning the my-polymer-b html file.

This issues breaks our current use of polymer elements and we're forced to refactor a large codebase towards many finer-grained libs we don't really need and will find difficult to move about as we refactor.

Here the code:

mypolymerA.html
<link rel="import" href="packages/polymer/polymer.html">

<polymer-element name="my-polymer-a">
    <template>
      <div>Hello I'm A</div>
    </template>
  <script type="application/dart" src="mypolymers.dart"></script>
</polymer-element>

mypolymerB.html
<link rel="import" href="packages/polymer/polymer.html">

<polymer-element name="my-polymer-b">
    <template>
      <div>Hello I'm B</div>
    </template>
  <script type="application/dart" src="mypolymers.dart"></script>
</polymer-element>

mypolymers.dart
import 'package:polymer/polymer.dart';

@CustomTag('my-polymer-a')
class MyPolymerA extends PolymerElement {
  
  MyPolymerA.created() : super.created();
  
}

@CustomTag('my-polymer-b')
class MyPolymerB extends PolymerElement {
  
  MyPolymerB.created() : super.created();
  
}