bp: a small wrapper to make promises bindable in Angular

bp.js

ngModule.factory('bp', function() {
  return function(q) {
    q.state = 'pending';
    q.isPending = true;
    q.isFulfilled = false;
    q.isRejected = false;
    q.then(function(result) {
      q.state = 'fulfilled';
      q.isPending = false;
      q.isFulfilled = true;
      q.isRejected = false;
      q.result = result;
    }, function(result) {
      q.state = 'rejected';
      q.isPending = false;
      q.isFulfilled = false;
      q.isRejected = true;
      q.result = result;
    });
    return q;
  }
});

ngModule.controller('ExampleCtrl', function(bp, $http) {
  var req = $http.get("http://example.com/foo.json");
  req = req.then(data => {
    return loadData(data);
  });
  this.req = bp(req);
})

example.html

<div ng-controller="ExampleCtrl as e">
  <span ng-if="e.req.isPending" class="loading-spinner"></span>
  <div ng-switch="e.req.state">
    <div ng-case-when="pending">Loading…</div>
    <div ng-case-default>Error loading data: {{ e.req.result }}</div>
    <div ng-case-when="fulfilled">
      Your data: {{ e.req.result }}
    </div>
  </div>
</div>