Create ingredient on element collection

In the element editor with have a feature that creates ingredients
that are defined but not created yet. Before we removed the abstract
class from Ingredient we needed to create the ingredient on the class
instead of the collection. Since the collection is eager loaded it has
to be updated with the newly created ingredient in order to prevent
the ingredient to be created twice (leading to unique index violation
errors).

app/decorators/alchemy/element_editor.rb

@@ -26,7 +26,7 @@ def contents
     # @return Array<Alchemy::IngredientEditor>
     def ingredients
       element.definition.fetch(:ingredients, []).map do |ingredient|
-        Alchemy::IngredientEditor.new(find_or_create_ingredient(ingredient[:role]))
+        Alchemy::IngredientEditor.new(find_or_create_ingredient(ingredient))
       end
     end
 
@@ -121,9 +121,12 @@ def create_content(name)
       Alchemy::Content.create(element: element, name: name)
     end
 
-    def find_or_create_ingredient(role)
-      element.ingredients.find { |i| i.role == role } ||
-        Ingredient.create(element: element, role: role)
+    def find_or_create_ingredient(definition)
+      element.ingredients.detect { |i| i.role == definition[:role] } ||
+        element.ingredients.create!(
+          role: definition[:role],
+          type: Alchemy::Ingredient.normalize_type(definition[:type]),
+        )
     end
   end
 end

spec/decorators/alchemy/element_editor_spec.rb

@@ -50,6 +50,42 @@
     end
   end
 
+  describe "#ingredients" do
+    let(:element) { create(:alchemy_element, :with_ingredients) }
+
+    subject(:ingredients) { element_editor.ingredients }
+
+    it "returns a ContentEditor instance for each ingredient defined" do
+      aggregate_failures do
+        ingredients.each do |ingredient|
+          expect(ingredient).to be_an(Alchemy::IngredientEditor)
+        end
+      end
+    end
+
+    context "with a ingredient defined but not existing yet" do
+      let(:element) { create(:alchemy_element, name: "headline") }
+
+      before do
+        expect(element).to receive(:definition).at_least(:once) do
+          {
+            name: "headline",
+            ingredients: [
+              {
+                role: "headline",
+                type: "Headline",
+              },
+            ],
+          }.with_indifferent_access
+        end
+      end
+
+      it "creates the missing ingredient" do
+        expect { subject }.to change { element.ingredients.count }.by(1)
+      end
+    end
+  end
+
   describe "#to_partial_path" do
     subject { element_editor.to_partial_path }