Chrome 38 : TypeError: Constructor Map requires 'new'

[lgersman]

The code generated by Traceur will no more run in current Chrome browser version 38 when you derive from class Map (which is natively available at this version). In Firefox (version 30, supports also native ES6 Maps) everything works fine ...

class MyMap extends Map {
  constructor() {
    super();
  }
}

will result in

"TypeError: Constructor Map requires 'new'
    at MyMap.Map (native)
    at Object.superCall 
    ....

You can try it live here :

Example : http://jsbin.com/rucoy/4/edit?html,js,console

Is that a bug of Traceur or the Chrome implementation of Map ?

[arv]

Little bit of both.
V8 does not yet support extending builtins and Traceur is not trying to work around this limitation.