Angular 2's property decorators don't work with Babel 5.x.

README.md

The _defineDecoratorPropertyDescriptor calls that Babel 5.x generates mess up @Input decorators somehow.

function Linker() {
  _classCallCheck(this, _Linker);

  _defineDecoratedPropertyDescriptor(this, 'name', _instanceInitializers);

  _defineDecoratedPropertyDescriptor(this, 'url', _instanceInitializers);
}

The Object.defineProperty(target, key, descriptor) does something...

function _defineDecoratedPropertyDescriptor(target, key, descriptors) {
  var _descriptor = descriptors[key];
  if (!_descriptor) return;
  var descriptor = {};
  for (var _key in _descriptor) descriptor[_key] = _descriptor[_key];
  descriptor.value = descriptor.initializer ? descriptor.initializer.call(target) : undefined;
  Object.defineProperty(target, key, descriptor); // This!
}

It seems like the defineProperty overrides the properties passed by the parent or avoids them updated.

Q. What's gonna happen on property initializers in TypeScript?

linker-babel.js

var _createDecoratedClass = (function () {
  function defineProperties(target, descriptors, initializers) {
    for (var i = 0; i < descriptors.length; i++) {
      var descriptor = descriptors[i];
      var decorators = descriptor.decorators;
      var key = descriptor.key;
      delete descriptor.key;
      delete descriptor.decorators;
      descriptor.enumerable = descriptor.enumerable || false;
      descriptor.configurable = true;
      if ('value' in descriptor || descriptor.initializer) descriptor.writable = true;
      if (decorators) {
        for (var f = 0; f < decorators.length; f++) {
          var decorator = decorators[f];
          if (typeof decorator === 'function') {
            descriptor = decorator(target, key, descriptor) || descriptor;
          } else {
            throw new TypeError('The decorator for method ' + descriptor.key + ' is of the invalid type ' + typeof decorator);
          }
        }
        if (descriptor.initializer !== undefined) {
          initializers[key] = descriptor;
          continue;
        }
      }
      Object.defineProperty(target, key, descriptor);
    }
  }
  return function (Constructor, protoProps, staticProps, protoInitializers, staticInitializers) {
    if (protoProps) defineProperties(Constructor.prototype, protoProps, protoInitializers);
    if (staticProps) defineProperties(Constructor, staticProps, staticInitializers);
    return Constructor;
  };
})();

function _defineDecoratedPropertyDescriptor(target, key, descriptors) {
  var _descriptor = descriptors[key];
  if (!_descriptor) return;
  var descriptor = {};
  for (var _key in _descriptor) descriptor[_key] = _descriptor[_key];
  descriptor.value = descriptor.initializer ? descriptor.initializer.call(target) : undefined;
  Object.defineProperty(target, key, descriptor);
}

var Linker = (function () {
  var _instanceInitializers = {};

  _createDecoratedClass(Linker, [{
    key: 'name',
    decorators: [(0, _angular2Angular2.Input)()],
    initializer: null,
    enumerable: true
  }, {
    key: 'url',
    decorators: [(0, _angular2Angular2.Input)()],
    initializer: null,
    enumerable: true
  }], null, _instanceInitializers);

  function Linker() {
    _classCallCheck(this, _Linker);

    _defineDecoratedPropertyDescriptor(this, 'name', _instanceInitializers);

    _defineDecoratedPropertyDescriptor(this, 'url', _instanceInitializers);
  }

  var _Linker = Linker;
  Linker = (0, _angular2Angular2.View)({
    template: '<p><a [href]="url" [title]="name">{{ name }}</a></p>'
  })(Linker) || Linker;
  Linker = (0, _angular2Angular2.Component)({
    selector: 'linker'
    // inputs: ['name', 'url']
  })(Linker) || Linker;
  return Linker;
})();

linker-typescript.js

var __decorate = (this && this.__decorate) || function(decorators, target, key, desc) {
  if (typeof Reflect === "object" && typeof Reflect.decorate === "function")
    return Reflect.decorate(decorators, target, key, desc);
  switch (arguments.length) {
  case 2:
    return decorators.reduceRight(function(o, d) {
      return (d && d(o)) || o;
    }
    , target);
  case 3:
    return decorators.reduceRight(function(o, d) {
      return (d && d(target, key)),
      void 0;
    }
    , void 0);
  case 4:
    return decorators.reduceRight(function(o, d) {
      return (d && d(target, key, o)) || o;
    }
    , desc);
  }
};
var __metadata = (this && this.__metadata) || function(k, v) {
  if (typeof Reflect === "object" && typeof Reflect.metadata === "function")
    return Reflect.metadata(k, v);
};

Linker = (function() {
  function Linker() {
  }
  __decorate([
  angular2_1.Input(),
  __metadata('design:type', String)
  ], Linker.prototype, "name");
  __decorate([
  angular2_1.Input(),
  __metadata('design:type', String)
  ], Linker.prototype, "url");
  Linker = __decorate([
  angular2_1.Component({
    selector: 'linker'
  }),
  angular2_1.View({
    template: '<p><a [href]="url" [title]="name">{{ name }}</a></p>'
  }),
  __metadata('design:paramtypes', [])
  ], Linker);
  return Linker;
})();