Ability to register custom template engines via Jasmine::Headless.register_engine hook

lib/jasmine/headless/files_list.rb

@@ -38,6 +38,7 @@ module Jasmine::Headless
 
       def reset!
         @asset_paths = nil
+        @registered_engines = {}
 
         # register haml-sprockets and handlebars_assets if it's available...
         %w{haml-sprockets handlebars_assets}.each do |library|
@@ -67,6 +68,21 @@ module Jasmine::Headless
           register_engine '.css', Jasmine::Headless::CSSTemplate
           register_engine '.jst', Jasmine::Headless::JSTTemplate
         end
+
+      end
+
+      def registered_engines
+        @registered_engines ||= {}
+      end
+
+      def register_engine(file_extension, template_class)
+        registered_engines[file_extension] = template_class
+      end
+
+      def register_engines!
+        registered_engines.each do |file_extension, template_class|
+          Sprockets.register_engine file_extension, template_class
+        end
       end
 
       def default_files
@@ -95,11 +111,21 @@ module Jasmine::Headless
       @required_files = UniqueAssetList.new
       @potential_files_to_filter = []
 
+      register_engines!
+
       load_initial_assets
 
       use_config if config?
     end
 
+    def register_engines!
+      begin
+        require spec_helper
+      rescue LoadError
+      end
+      self.class.register_engines!
+    end
+
     def load_initial_assets
       self.class.default_files.each do |file|
         begin
@@ -301,5 +327,17 @@ module Jasmine::Headless
         end
       end
     end
+
+    def spec_helper
+      File.join(spec_dir, "helpers", "spec_helper")
+    end
   end
 end
+
+module Jasmine::Headless
+  extend self
+
+  def register_engine(file_extension, template_class)
+    Jasmine::Headless::FilesList.register_engine(file_extension, template_class)
+  end
+end

spec/lib/jasmine/headless/files_list_spec.rb

@@ -218,6 +218,21 @@ describe Jasmine::Headless::FilesList do
         files_list.files.any? { |file| file['.erb'] }.should be_false
       end
     end
+
+    describe "#register_engine!" do
+
+      before(:each) do
+        Jasmine::Headless::FilesList.reset!
+      end
+
+      it "should register code added via configure blocks" do
+        template_class = mock()
+        described_class.register_engine ".foo", template_class
+        Sprockets.expects(:register_engine).with(".foo", template_class)
+        described_class.new
+      end
+
+    end
   end
 end