gistfile1.js

Ember.Test.registerHelper('selectFrom', 
  function(app, selector, value, description) {
    // choose an option
    find(selector).val(value);
    // trigger the change
    find(selector).change();
    // assert the selected option
    equal(find(selector+" option:selected").val(), value, description||"makes the selection");
    // promise
    return wait();
  }
);