Chapter 4: test MultiRecipeLoader spec suggestions & fix

[so0k]

current github code:

  describe('MultiRecipeLoader', function() {
    var mockBackend, recipe, loader;
    // The _$httpBackend_ is the same as $httpBackend. Only written this way to
    // differentiate between injected variables and local variables
    beforeEach(inject(function(_$httpBackend_, Recipe, MultiRecipeLoader) {
      recipe = Recipe;
      mockBackend = _$httpBackend_;
      loader = MultiRecipeLoader;
    }));

    it('should load list of recipes', function() {
      mockBackend.expectGET('/recipes').respond([{id: 1}, {id: 2}]);

      var recipes;

      var promise = loader();
      promise.then(function(rec) {
        recipes = rec;
      });

      expect(recipes).toBeUndefined();

      mockBackend.flush();

      expect(recipes).toEqualData([{id: 1}, {id: 2}]);
    });
  });

1. first I'd suggest the usage of leading and trailing underscores for all injected variables. the book is not explaining these are ignored by the injector and using this notation helps to highlight injected variables.
2. second, I'd like to point out that the spec will fail as "loader" is the actually promise object and not a function.

my suggestion would be: (this is wrapped in a services test suite where the Recipe resource and $httpBackend mock are scoped for all individual service test suites)

var Recipe,
    $httpBackend;

  describe('MultiRecipeLoader', function(){
    var MultiRecipeLoader;
    //injector will ignore front and trailing underscore, this notation is to clarify injected variables
    //yet give the ability to write tests using variables exactly the same way the actual implementations do
    beforeEach(inject(function (_$httpBackend_, _Recipe_, _MultiRecipeLoader_) {
      Recipe = _Recipe_;
      $httpBackend = _$httpBackend_;
      MultiRecipeLoader = _MultiRecipeLoader_;
    }));

    it('should load a list of recipes', function () {
      $httpBackend.expectGET('/recipes').respond([{id:1}, {id:2}]);

      var recipes;
      var promise = MultiRecipeLoader;
      promise.then(function(rec){
        recipes = rec;
      });

      expect(recipes).toBeUndefined();

      $httpBackend.flush();

      expect(recipes).toEqualData([{id:1},{id:2}]);
    });